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AIST3 
* /---   FILE TYPE = E
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         IDENT     AIST3
         ORG       0040H
OFFSET   EQU       *-40H
         SPACE     15 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
* 
* INFORMATION SYSTEMS TERMINAL 3 (IST-III)
*        ASCII RAM RESIDENT LOAD FILE 
*        PROCESSOR...Z80
* 
*         VERSION 02     03/30/81      DSN LOAD FILE 00 
* 
*         CC 15632600        CONTROLWARE ID MF401-JO2 
*         TLA 15632812
* 
* CONTAINS THE FOLLOWING CODE.
*        1. ASCII/PLATO RESIDENT CODE      SEE ERS 16042872.
*        2. ASCII/GRAPHICS RESIDENT CODE   SEE ERS 16042873.
*        3. ASCII/TIMESHARE RESIDENT CODE  SEE ERS 16042874.
* 
*        SCREEN COPY IS AVAILABLE IN ALL THREE MODES. 
*        COMM LINE PRINT IS AVAILABLE IN TIMESHARE AND
*        GRAPHIC MODES. 
* 
* THIS FILE IS INTENDED TO BE LOADED WITH THE ASCII LOADER. 
*        SEE ERS 16042871.
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
         SPACE     4
*        COPYRIGHT CONTROL DATA CORPORATION 1980
*                  FOR INTERNAL USE ONLY
*                  NOT A RELEASED PRODUCT 
         EJECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
* 
* SWITCH ASSIGNMENTS
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
* 
*        FRONT PANEL SWITCHES 
* 
*         -CLOSED/ON/0-         -OPEN/OFF/1-
*  SE-1  NORMAL LOAD FILE      SELECT LOAD FILE 
*  SE-2  INTERNAL LOAD SOURCE  EXTERNAL LOAD SOURCE 
*  SE-3  HOST LOAD SOURCE      LOCAL LOAD SOURCE
*  SE-4  SKIP DIAGNOSTICS      RUN DIAGNOSTICS
*  SE-5  SKIP KB/TP TEST       RUN KB/TP TEST 
*  SE-6  LOUD BEEPER           SOFT BEEPER
*  SE-7  (NOT USED) 
*  SE-8  HALF DUPLEX           FULL DUPLEX
*  SE-9  ODD PARITY            EVEN PARITY
*  SE-10 PARITY OFF            PARITY ON
* 
*        CONFIGURATION SWITCHES 
* 
*         -CLOSED/ON/0-         -OPEN/OFF/1-
*  S2-1  SWITCHED DTR          CONSTANT DTR 
*  S2-2  (NOT USED) 
*  S2-3  PCN TRANSMIT RATE SELECT 
*  S2-4  PCN TRANSMIT RATE SELECT 
*  S2-5  PCN TRANSMIT RATE SELECT 
*  S2-6  (NOT USED) 
*  S2-7  SECONDARY CHAN XMIT   PRIMARY CHAN XMIT
*  S2-8  EXIT DIAGNOSTICS      LOOP ON DIAGNOSTICS
*  S2-9  NO TOUCH PANEL        TOUCH PANEL PRESENT
*  S2-10 16K RAM               32K RAM
* 
*        INTERNAL SWITCHES
* 
*         -CLOSED/ON/0-         -OPEN/OFF/1-
*  S5-1  PCN DEFAULT LOAD FILE SELECT BIT 0 
*  S5-2  PCN DEFAULT LOAD FILE SELECT BIT 1 
*  S5-3  ASCII DEFAULT LOAD FILE SELECT BIT 0 
*  S5-4  ASCII DEFAULT LOAD FILE SELECT BIT 1 
*  S5-5  (NOT USED) 
*  S5-6  DEFAULT ASCII COMM DATA RATE SELECT BIT 0
*  S5-7  DEFAULT ASCII COMM DATA RATE SELECT BIT 1
*  S5-8  DEFAULT ASCII COMM DATA RATE SELECT BIT 2
 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
* 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
*        BIT ASSIGNMENTS FOR INPUT ADDRESSES
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
 
* INPUT ADDRESS 00 (MAINTENANCE SWITCHES) 
*  7  S2-8 (1=LOOP ON DIAG, 0=EXIT DIAG)
*  6  S2-9 (1=TP PRESENT, 0=NO TP)
*  5  S2-10(1=32K RAM, 0=16K RAM) 
*  4  SE-5 (1=DO KB/TP TEST, 0=SKIP KB/TP TEST) 
*  3  SE-4 (1=DO DIAGNOSTICS, 0=SKIP DIAGNOSTICS) 
*  2  SE-3 (1=LOCAL LOAD SOURCE, 0=HOST LOAD SOURCE)
*  1  SE-2 (1=EXTERNAL LOAD, 0=INTERNAL LOAD) 
*  0  SE-1 (1=SELECT LOAD, 0=NORMAL LOAD) 
 
* INPUT ADDRESS 01 (KEYBOARD INPUT DATA)
*  7  KEYBOARD BIT 7, CONTROL BIT (1=ON, 0=OFF) 
*  6  KEYBOARD BIT 6
*  5  KEYBOARD BIT 5, SHIFT BIT (1=ON, 0=OFF) 
*  4  KEYBOARD BIT 4
*  3  KEYBOARD BIT 3
*  2  KEYBOARD BIT 2
*  1  KEYBOARD BIT 1
*  0  KEYBOARD BIT 0
 
* INPUT ADDRESS 02 (TOUCH PANEL INPUT DATA) 
* 7-4  X POSITION BITS 3-0
* 3-0  Y POSITION BITS 3-0
 
* INPUT ADDRESS 03 (LOWER ID BITS)
 
* INPUT ADDRESS 04 (UPPER ID BITS)
 
* INPUT ADDRESS 05 (INTERNAL SWITCHES)
*  7  S5-8 ASCII DEFAULT COMM DATA RATE SELECT BIT 2* 
*  6  S5-7 ASCII DEFAULT COMM DATA RATE SELECT BIT 1* 
*  5  S5-6 ASCII DEFAULT COMM DATA RATE SELECT BIT 0* 
*  4  S5-5 (1=OPEN, 0=CLOSED) 
*  3  S5-4 ASCII DEFAULT LOAD FILE SELECT BIT 1 
*  2  S5-3 ASCII DEFAULT LOAD FILE SELECT BIT 0 
*  1  S5-2 PCN DEFAULT LOAD FILE SELECT BIT 1 
*  0  S5-1 PCN DEFAULT LOAD FILE SELECT BIT 0 
* 
*        *NOTE. 
*         SWITCHES 8-6 ARE USED TO SELECT ASCII COMM
*         DEFAULT DATA RATE FOR LOADER AND RESIDENT.
*         RATES ARE AS FOLLOWS. 
*         SW 8-6   X64 CLOCK   X32 CLOCK   X16 CLOCK
*             0       75 BPS     150 BPS     300 BPS
*             1      150 BPS     300 BPS     600 BPS
*             2      300 BPS     600 BPS    1200 BPS
*             3      600 BPS    1200 BPS    2400 BPS
*             4     1200 BPS    2400 BPS    4800 BPS
*             5     2400 BPS    4800 BPS    9600 BPS
*             6     4800 BPS    9600 BPS   19200 BPS
*             7    EXT CLK X1  EXT CLK X1  EXT CLK X1 
 
*  INPUT ADDRESS 06 (COMMUNICATIONS SWITCHES AND STATUS)
*  7  SERIAL I/O DSR (1=ON, 0=OFF)
*  6  S2-6 (1=OPEN, 0=CLOSED) 
*  5  SE-10 (1=PARITY ON, 0=PARITY OFF) 
*  4  SE-9 (1=EVEN PARITY, 0=ODD PARITY)
*  3  TALK/DATA SWITCH (1=DATA, 0=TALK) 
*  2  S2-1 (1=CONSTANT DTR, 0=SWITCHED DTR) 
*  1  SE-8 (1=FULL DUPLEX, 0=HALF DUPLEX) 
*  0  SE-7 (1=OPEN, 0=CLOSED) 
 
* INPUT ADDRESS 07 (CONTROLLER STATUS)
*  7  BULK ERASE BUSY (1=BUSY, 0=NOT BUSY)
*  6  RESET SWITCH (1=RESET OFF, 0=RESET ON)
*  5  PARALLEL I/O TIMEOUT (1=TIMEOUT, 0=NO TIMEOUT)
*  4  TOUCH PANEL DATA READY (1=DATA READY, 0=NO DATA READY)
*  3  KEYBOARD DATA READY (1=DATA READY, 0=NO DATA READY) 
*  2  PCN TRANSMIT DATA REQUEST (1=REQUEST, 0=NO REQUEST) 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
*  1  HARDWARE FLAG (1=FLAG ON, 0=FLAG OFF)*
*  0  PCN RECEIVE DATA READY (1=READY, 0=NOT READY) 
* 
*        *NOTE. 
*         HARDWARE FLAG IS SET TO 1 BY A POWER ON RESET.
 
* INPUT ADDRESS 08 (PCN RECEIVE DATA) 
* FIRST BYTE
*   7  FIRST BYTE FLAG (=1) 
*   6  START BIT (=1) 
*  5-0 DATA BITS 19-14
* SECOND BYTE 
*   7  FIRST BYTE FLAG (=0) 
*  6-0 DATA BITS 13-07
* THIRD BYTE
*   7  FIRST BYTE FLAG (=0) 
*  6-1 DATA BITS 06-01
*   0  DATA BIT 00 (EVEN PARITY ON DATA BITS 19-01) 
* 
*        NOTE. ADDRESSES 09-0F ARE ALSO PCN RECEIVE DATA
*        DUE TO INCOMPLETE ADDRESS DECODE.
 
* INPUT ADDRESS 10 (ASCII COMM RECEIVE DATA)
* Z80-SIO/2 A PORT
* 
*        NOTE. ADDRESSES 14, 18 AND 1C ARE ALSO ASCII COMM
*        RECEIVE DATA DUE TO INCOMPLETE ADDRESS DECODE. 
 
* INPUT ADDRESS 11 (ASCII COMM STATUS)
* Z80-SIO/2 A PORT
* 
*        NOTE. ADDRESSES 15, 19 AND 1D ARE ALSO ASCII COMM
*        STATUS DUE TO INCOMPLETE ADDRESS DECODE. 
 
* INPUT ADDRESS 12 (SERIAL I/O RECEIVE DATA)
* Z80-SIO/2 B PORT
* 
*        NOTE. ADDRESSES 16, 1A AND 1E ARE ALSO SERIAL I/O
*        RECEIVE DATA DUE TO INCOMPLETE ADDRESS DECODE. 
 
* INPUT ADDRESS 13 (SERIAL I/O STATUS)
* Z80-SIO/2 B PORT
* 
*        NOTE. ADDRESSES 17, 1B AND 1F ARE ALSO SERIAL I/O
*        STATUS DUE TO INCOMPLETE ADDRESS DECODE. 
 
* INPUT ADDRESS 2X-3X (PARALLEL I/O INPUT DATA OR STATUS) 
 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
* 
*        BIT ASSIGNMENTS FOR OUTPUT ADDRESSES 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
 
* OUTPUT ADDRESS 00 (MAINTENANCE REGISTER)
*  7  ROM/RAM ENABLE (1=RAM, 0=ROM) 
*  6  TEST MODE SELECT (1=NORMAL MODE, 0=TEST MODE) 
*  5  DTR LIGHT (1=OFF, 0=ON) 
*  4  DSR LIGHT (1=OFF, 0=ON)*    *DSR, RTS, RCV AND XMT
*  3  RTS LIGHT (1=OFF, 0=ON)*     LIGHTS ARE ONLY AVAILABLE
*  2  RCV LIGHT (1=OFF, 0=ON)*     TO SOFTWARE IN TEST MODE.
*  1  XMT LIGHT (1=OFF, 0=ON)*     IN NORMAL MODE THEY ARE
*  0  ERR LIGHT (1=OFF, 0=ON)      DRIVEN BY HARDWARE.
 
*        NOTE. ALL MAINTENANCE REGISTER BITS ARE RESET TO 0 
*        BY ANY RESET OPERATION.
 
* OUTPUT ADDRESS 01 (PCN TRANSMIT DATA LOWER BITS)
* 7-4 DATA BITS 04-01 
*  3  DATA BIT 00 (EVEN PARITY ON DATA BITS 10-01)
* 2-0 NOT USED
 
* OUTPUT ADDRESS 02 (PCN TRANSMIT DATA UPPER BITS)
* 7-6 NOT USED
* 5-0 DATA BITS 10-05 
 
* OUTPUT ADDRESS 03 (VIDEO CONTROL) 
*  7-3 NOT USED 
*  2  BULK OPERATION (1=DO BULK OPER, 0=DO NOT DO BULK OPER)
*  1  ENABLE/DISABLE VIDEO (1=ENABLE, 0=DISABLE)
*  0  WRITE/ERASE IF DOING BULK OPERATION (1=WRITE,0=ERASE) 
 
* OUTPUT ADDRESS 04 (LOAD INTERRUPT MASK) 
*  7  PCN DATA READY    (1=ENABLE, 0=DISABLE) (VECTOR=00) 
*  6  KYBD DATA READY   (1=ENABLE, 0=DISABLE) (VECTOR=04) 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
*  5  TP DATA READY     (1=ENABLE, 0=DISABLE) (VECTOR=06) 
*  4  PCN DATA REQUEST  (1=ENABLE, 0=DISABLE) (VECTOR=02) 
*  3  EXT CHANNEL       (1=ENABLE, 0=DISABLE) (VECTOR=0C) 
*  2  LONG INTERVAL     (1=ENABLE, 0=DISABLE) (VECTOR=0E) 
*  1  SHORT INTERVAL    (1=ENABLE, 0=DISABLE) (VECTOR=0A) 
*  0  I/O TIMEOUT       (1=ENABLE, 0=DISABLE) (VECTOR=08) 
* 
*        NOTE. LONG INTERVAL INTERRUPT IS 17.5 MSEC.
*              SHORT INTERVAL INTERRUPT IS 0.833 MSEC.
 
* OUTPUT ADDRESS 05 (MISCELLANEOUS CONTROL) 
*  7  1=SELECT RAM FOR OPERAND PART OF NEXT INSTRUCTION 
*  6  SELECT EXTERNAL MODEM CONTROL (1=SELECT, 0=NO SELECT) 
*  5  SELECT INTERNAL MODEM CONTROL (1=SELECT, 0=NO SELECT) 
*  4  SELECT ASCII INTERFACE CONTROL (1=SELECT, 0=NO SELECT)
*  3  SELECT PLATO INTERFACE CONTROL (1=SELECT, 0=NO SELECT)
*  2  HARDWARE FLAG CONTROL (1=SET, 0=RESET)
*  1  I/O TIMEOUT STATUS/INTERRUPT (1=RESET, 0=DO NOT RESET)
*  0  ALARM CONTROL (1=SOUND ALARM, 0=DO NOT SOUND ALARM) 
 
* OUTPUT ADDRESS 06 (ASCII COMM DATA RATE)
* 7-5 RECEIVE DATA BIT RATE 
* 4-2 TRANSMIT DATA BIT RATE
* 1-0 NOT USED
*       BITS 7-5   X64 CLOCK   X32 CLOCK   X16 CLOCK
*             0       75 BPS     150 BPS     300 BPS
*             1      150 BPS     300 BPS     600 BPS
*             2      300 BPS     600 BPS    1200 BPS
*             3      600 BPS    1200 BPS    2400 BPS
*             4     1200 BPS    2400 BPS    4800 BPS
*             5     2400 BPS    4800 BPS    9600 BPS
*             6     4800 BPS    9600 BPS   19200 BPS
*             7    EXT CLK X1  EXT CLK X1  EXT CLK X1 
 
* OUTPUT ADDRESS 07 (SERIAL I/O DATA RATE)
* 7-5 XMIT AND RCV DATA BIT RATE
* 4-1 NOT USED
*  0  EXTERNAL INTERFACE SELECT (1=LONG LINE, 0=RS232)
*       BITS 7-5   X64 CLOCK   X32 CLOCK   X16 CLOCK
*             0       37.5 BPS    75 BPS     150 BPS
*             1       75 BPS     150 BPS     300 BPS
*             2      150 BPS     300 BPS     600 BPS
*             3      300 BPS     600 BPS    1200 BPS
*             4      600 BPS    1200 BPS    2400 BPS
*             5     1200 BPS    2400 BPS    4800 BPS
*             6     2400 BPS    4800 BPS    9600 BPS
*             7     4800 BPS    9600 BPS   19200 BPS
 
* OUTPUT ADDRESS 08-0F (NOT USED) 
 
* OUTPUT ADDRESS 10 (ASCII COMM TRANSMIT DATA)
* Z80-SIO/2 A PORT
* 
*        NOTE. ADDRESSES 14, 18 AND 1C ARE ALSO ASCII COMM
*        TRANSMIT DATA DUE TO INCOMPLETE ADDRESS DECODE.
 
* OUTPUT ADDRESS 11 (ASCII COMM CONTROL)
* Z80-SIO/2 A PORT
* 
*        NOTE. ADDRESSES 15, 19 AND 1D ARE ALSO ASCII COMM
*        CONTROL DUE TO INCOMPLETE ADDRESS DECODE.
 
* OUTPUT ADDRESS 12 (SERIAL I/O TRANSMIT DATA)
* Z80-SIO/2 B PORT
* 
*        NOTE. ADDRESSES 16, 1A AND 1E ARE ALSO SERIAL I/O
*        TRANSMIT DATA DUE TO INCOMPLETE ADDRESS DECODE.
 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
* OUTPUT ADDRESS 13 (SERIAL I/O CONTROL)
* Z80-SIO/2 B PORT
* 
*        NOTE. ADDRESSES 17, 1B AND 1F ARE ALSO SERIAL I/O
*        CONTROL DUE TO INCOMPLETE ADDRESS DECODE.
 
* OUTPUT ADDRESS 2X-3X (PARALLEL I/O OUTPUT DATA OR COMMAND)
 
 
* INTERNAL PCN MODEM INFORMATION
*        MODEM GENERATES DSR, CD AND RD.
*        MODEM LOOKS AT TD. 
*        RTS, DTR AND CTS ARE NOT USED. 
*        TERMINAL GATES RD WITH CD AND DSR. 
 
* I/O INPUT ADDRESS ASSIGNMENTS 
 
MNTSW    EQU       00H        MAINTENANCE SWITCHES
KBDATA   EQU       01H        KEYBOARD DATA 
TPDATA   EQU       02H        TOUCH PANEL DATA
IDLO     EQU       03H        ID CODE, LOWER 8 BITS 
IDUP     EQU       04H        ID CODE, UPPER 8 BITS 
INTSW    EQU       05H        INTERNAL SWITCHES 
COMMSW   EQU       06H        COMM CONTROL SWITCHES 
SYSSTAT  EQU       07H        CONTROLLER STATUS 
CLADATA  EQU       08H        PCN RECEIVE DATA
ASCDATI  EQU       10H        ASCII COMM RECEIVE DATA 
ASCSTAT  EQU       11H        ASCII COMM STATUS 
SERDATI  EQU       12H        SERIAL I/O RECEIVE DATA 
SERSTAT  EQU       13H        SERIAL I/O STATUS 
FDDATA   EQU       0EEH       FLOPPY DISK INPUT DATA
FDSTAT   EQU       0EFH       FLOPPY DISK STATUS
 
* I/O OUTPUT ADDRESS ASSIGNMENTS
 
PNLLTS   EQU       00H        MAINTENANCE PANEL LIGHTS
CLAL     EQU       01H        PCN TRANSMIT DATA LOWER BITS
CLAU     EQU       02H        PCN TRANSMIT DATA UPPER BITS
VIDEOCTL EQU       03H        BULK ERASE AND VIDEO ENABLE 
INTMSK   EQU       04H        SYSTEM INTERRUPT MASK 
MISCTL   EQU       05H        MISCELLANEOUS CONTROL 
ASCRATE  EQU       06H        ASCII COMM DATA RATE
SERRATE  EQU       07H        SERIAL I/O DATA RATE
ASCDATO  EQU       10H        ASCII COMM TRANSMIT DATA
ASCCTRL  EQU       11H        ASCII COMM CONTROL
SERDATO  EQU       12H        SERIAL I/O TRANSMIT DATA
SERCTRL  EQU       13H        SERIAL I/O CONTROL
FDCMND   EQU       0EFH       FLOPPY DISK COMMAND 
         EJECT
* * * * * * * * * * * * * * * * * * * * * * * * * * * * *@* * 
* 
*        PRINTER EQUATES
* 
* * * * * * * * * * * * * * * * * * * * * * * * * * * * *@* * 
DATAFCN  EQU       2AH        001NNNN0
CNTLFCN  EQU       2BH        001NNNN1
MISCFCN  EQU       05H        00000101
MRESET0  EQU       00H        RESET INTERFACE 
MRESET1  EQU       01H        RESET PTR 
DISABLE  EQU       2          DISABLE INTERRUPTS. 
ENABLE   EQU       04H        ENABLE INTERRUPTS.
SECSTAT  EQU       09H        REQUEST SECONDARY STATUS. 
READID   EQU       08H        READ DEVICE ID. 
STIMER   EQU       0EH        START TIMER.
* 
C.ENQ    EQU       05H        DOT ROW PREAMBLE
C.LF     EQU       0AH        LINE / ROW FEED 
C.FF     EQU       0CH        FORM FEED 
PDISABL  EQU       13H        DESELECT PRINTER. 
         EJECT     EXTERNAL EQUATES 
         SPACE     5
* /---   BLOCK      NORTHS     00 000   73/00/00  00.00 
*        USER JUMP TABLE ADDRESSES
         SPACE     2
FWA1     EQU       *          START OF FIRST CHECKSUM AREA
R.INIT   JP        INIT 
R.DOT    JP        POINT
R.LINE   JP        LINE 
R.CHARS  JP        CHARS
R.BLOCK  JP        BLOCK
R.INPX   JP        INPX 
R.INPY   JP        INPY 
R.OUTX   JP        OUTX 
R.OUTY   JP        OUTY 
R.XMIT   JP        TX.STOR
R.MODE   JP        MODESET
R.STEPX  JP        STEPX
R.STEPY  JP        STEPY
R.WE     JP        WE 
R.DIR    JP        DIR
R.INPUT  JP        INPUT
R.SSF    JP        SSF0 
R.CCR    JP        CCR
R.EXTOUT JP        EXTX 
R.EXEC   JP        EXEC 
R.GJOB   JP        GJOB 
R.XJOB   JP        XJOB 
R.RETURN JP        RETURN 
R.CHRCV  JP        CONVERT
R.ALARM  JP        ALARM
         EJECT
         ORG       00F0H+OFFSET 
 
CKSMTBST EQU       *
         DEFW      FWA1       ENTRY POINTS AND CKSM TABLE 
         DEFW      LENGTH1
         DEFW      FWA2       COMMON RESIDENT CODE
         DEFW      LENGTH2
         DEFW      FWA3       401X UNIQUE CODE
         DEFW      LENGTH3
         DEFW      0          END OF TABLE
         DEFW      0            (LENGTH = 0)
 
LENGTH1  EQU       *-FWA1     END OF FIRST CHECKSUM AREA
FWA2     EQU       *          START OF SECOND CHECKSUM AREA 
* 
*        INTERRUPT VECTOR TABLE 
* LOWER 8 BITS OF INTERRUPT VECTOR FIXED AT 00
* UPPER 8 BITS INITIALIZED IN PROGRAM TO (100H+OFFSET)/100H.
* 
         ORG       0100H+OFFSET 
 
IVT      EQU       *
         DEFW      BADINT     PLATO CLA CHARACTER READY 
         DEFW      BADINT     PLATO CLA CHARACTER REQUEST 
         DEFW      KYBD       KEYBOARD DATA 
         DEFW      TP         TOUCH PANEL DATA
         DEFW      BADINT     EXTERNAL I/O TIMEOUT
         DEFW      BADINT     SHORT INTERVAL
         DEFW      EXTI       EXTERNAL CHANNEL
         DEFW      LINT       LONG INTERVAL 
         DEFW      BADINT     SERIAL I/O CHARACTER REQUEST
         DEFW      BADINT     SERIAL I/O EXT/STATUS CHANGE
         DEFW      EXTI       SERIAL I/O CHARACTER READY
         DEFW      EXTI       SERIAL I/O ERROR
         DEFW      ASCCREQ    ASCII COMM CHARACTER REQUEST
         DEFW      ASCXTCHG   ASCII COMM EXT/STATUS CHANGE
         DEFW      ASCCRDY    ASCII COMM CHARACTER READY
         DEFW      ASCERR     ASCII COMM ERROR
 
BADINT   JR        BADINT     ILLEGAL INTERRUPT 
         EJECT     TERMINAL INITIALIZATION
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        TERMINAL INITIALIZATION
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
 
*        INITIALIZATION ENTRY POINT.
INIT     EQU       *
         DI                   DISABLE INTERRUPTS
         LD        A,0DFH     CLEAR TEST MODE, ENABLE RAM 
         OUT       (PNLLTS),A   SET DTR, CLEAR ERR LIGHT
 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        SP,ZSTACK  SET STACK POINTER 
         LD        HL,CKSMTBST  PRESET CHECKSUM TABLE 
         LD        (CKSUMTBL),HL    ADDRESS 
         LD        A,01H      SOUND BEEPER
         OUT       (MISCTL),A 
 
         LD        A,(RESETFLG)  IS THIS A SHORT RESET
         XOR       3CH
         JR        Z,INIT1    JUMP IF YES 
 
* INITIALIZE AFTER LOAD 
         LD        A,(LDSOURCE) 
         LD        B,A
         AND       80H
         LD        (MODE),A 
         LD        A,3CH
         XOR       B
         LD        (RESETFLG),A 
 
         LD        HL,BEGVAR1 CLEAR VARIABLE SCRATCH AREA 
         LD        (HL),0 
         LD        DE,BEGVAR1+1 
         LD        BC,ENDVAR1-BEGVAR1-1 
         LDIR 
         LD        HL,BEGVAR2 
         LD        (HL),0 
         LD        DE,BEGVAR2+1 
         LD        BC,ENDVAR2-BEGVAR2-1 
         LDIR 
 
         LD        A,(RUNINFO)  GET DEFAULT RATE FOR
         RLCA                     STATUS LINE 
         RLCA 
         RLCA 
         AND       07H
         LD        (ASCSPEED),A 
         IN        A,(COMMSW) GET DEFAULT PARITY SETTING
         RLCA                   FOR STATUS LINE 
         RLCA 
         RLCA 
         RLCA 
         AND       03H
         XOR       03H
         CP        03H
         JR        NZ,INITPAR 
         DEC       A
INITPAR  EQU       *
         LD        (PARITY),A 
 
         IN        A,(COMMSW)  GET DEFAULT HALF/FULL DUPLEX 
         RRCA                   SETTING FOR STATUS LINE 
         AND       01H
         LD        (DUPLEXFG),A 
 
* ALL RESETS COME THROUGH THE FOLLOWING CODE
INIT1    EQU       *
         LD        A,38H
         LD        (M.STATUS),A    SET USER PROGRAM NOT RUN.
         XOR       A          FLAG USER PROGRAM NOT RUNNING 
         LD        (USERFLG),A
         CALL      INIT3      INIT INTS AND CHECKSUM
         LD        HL,USBUF   CLEAR OUT KB/TP BUFFER
         XOR       A
         LD        (HL),A 
         INC       HL 
         LD        (HL),A 
         INC       HL 
         LD        (HL),A 
* 
         LD        A,(LDSOURCE) 
         INC       A         TEST FOR MICRO TUTOR LOAD
         JR        Z,INITA   INITIALIZE FOR PLATO 
* 
         LD        A,(MODE)   CHECK PLATO/ASCII OPERATION 
         RLCA 
         JR        NC,INIT1A  JUMP IF ASCII (TS OR GRAPHIC) 
 
INITA    EQU       *
         CALL      PINIT.1    DO PLATO OPERATION INIT 
         CALL      SENDNAK    SEND NAK AND SET ABORT STATE
         LD        HL,0382H   SEND RESET STATUS TO PLATO
         CALL      R.XMIT 
         JR        INIT1C 
 
INIT1A   EQU       *
         LD        A,(TGMODE)  ASCII, SO CHECK TS OR GRAPHIC
         OR        A
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         JR        Z,INIT1B   JUMP IF TIMESHARE 
 
         CALL      AINIT.G    GRAPHIC OPERATION INIT
         JR        INIT1C 
 
INIT1B   EQU       *
         CALL      AINIT      TIMESHARE OPERATION INIT
 
INIT1C   EQU       *
         LD        A,(VERSION)  SET CONTROLWARE VERSION 
         LD        (M.VERS),A 
         LD        HL,0000H   SELECT M0/FWD/SIZE 1/HOR PLOT 
         CALL      R.CCR        AND CLEAR UNCOVER FLAG
 
         LD        A,01H      LOAD IST3 SUBTYPE 
         LD        (M.SBTYPE),A 
         LD        HL,M.TYPE  SET TERMINAL TYPE 
         IN        A,(MNTSW)  GET SWITCH S2-10(32K) 
         AND       60H        SAVE TP AND MEM BITS IN 
         LD        (M.CONFIG),A  CONFIGURATION BYTE 
         AND       20H        AND PUT IN BIT 4 OF M.TYPE
         RRCA 
         OR        12         SET ASCII TERMINAL TYPE 
         LD        (HL),A       IN BITS 3..0
 
INIT2    EQU       *
         LD        HL,0       DISPLAY 
         CALL      R.OUTY       .TERMINAL READY NN. 
         LD        HL,184       MESSAGE 
         CALL      R.OUTX 
         LD        HL,TRMRDY
         CALL      R.CHARS
         LD        HL,LDSOURCE
         INC       (HL)       TEST FOR DISK LOAD
* 
         CALL      Z,5306H    GO TO INTERPRETER 
* 
         XOR       A
         LD        (LDSOURCE),A 
 
         LD        A,(MODE)   CHECK ASCII/PLATO 
         RLCA 
         CALL      NC,AFF.1   HOME CURSOR FOR TS OR GRAPHIC 
         JP        CHKCARR    GO CHECK FOR CARRIER
 
INIT3    EQU       *
         LD        HL,IVT     SET INT TABLE ADDRESS 
         LD        A,H            (UPPER BITS)
         LD        I,A           INTO INT. VECTOR 
         IM        2          SET FOR MODE 2 INTERRUPTS 
         LD        HL,0444H   ENABLE KEYBOARD AND 
         CALL      R.SSF        LONG INTERVAL INTERRUPTS
         LD        HL,ASCPKGI SET UP ASCII INIT PACKAGE 
         LD        DE,ASCPKG
         LD        BC,8 
         LDIR 
         CALL      STAT.F1    SET UP SIO
         LD        B,8
         LD        C,SERCTRL
         LD        HL,SERPKGI 
         OTIR 
         CALL      CHKSUM.I   INITIALIZE MEMORY CHECKSUM
         EI 
         RET
 
ASCSETUP EQU       *
         LD        B,8        SET UP ASCII COMM PORT
         LD        C,ASCCTRL
         LD        HL,ASCPKG
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         OTIR 
         RET
 
ASCPKGI  EQU       *          ASCII COMM INIT PACKAGE 
         DEFB      04H        REG. 4 NEXT 
         DEFB      0C4H       X64 CLK, 1 STOP BIT, NO PARITY
         DEFB      03H        REG. 3 NEXT 
         DEFB      0C1H       8 BITS/CH, NO AUTO EN, EN RCVR
         DEFB      05H        REG. 5 NEXT 
         DEFB      0EAH       DTR ON,8 BITS/CH,TX EN,RTS ON 
         DEFB      01H        REG. 1 NEXT 
         DEFB      1BH        PAR NOT AFF VECT,EN TX/EXT INT
 
SERPKGI  EQU       *          SERIAL I/O INIT PACKAGE 
         DEFB      00H        REG. 0 NEXT 
         DEFB      18H        CHANNEL CLEAR, REG. 0 NEXT
         DEFB      04H        REG. 4 NEXT 
         DEFB      0C4H       X64 CLK,1 STOP BIT,NO PARITY
         DEFB      01H        REG. 1 NEXT 
         DEFB      04H        DIS RCV INT, STAT AFF VECT
         DEFB      02H        REG. 2 NEXT 
         DEFB      10H        INTERRUPT VECTOR = XX10H
         EJECT
**********
* PLATO INITIALIZE
**********
PINIT    EQU       *
         LD        A,01H      SET ERROR PROTOCOL TO STATE 0 
         LD        (EREG),A 
         LD        A,20       INIT WORD COUNTER 
         LD        (E.CNTR),A 
         LD        C,06H      SEND ACK
         CALL      XMIT.1 
         LD        C,0+20H    SEND 00 WORD COUNT
         CALL      XMIT.1 
 
PINIT.1  EQU       *
         LD        A,01 
         LD        (BYPASS),A   SET BYPASS
* 
PINIT.2  EQU       *
         LD        A,80H
         LD        (MODE),A  SET PLATO MODE 
         LD        HL,M0CODE00  SET UP M.M0 
         LD        (M.M0),HL
         XOR       A          SET (M.KSW) TO PUT INPUT DATA 
         LD        (M.KSW),A    INTO THE TRANSMIT BUFFER
         LD        (CURSAVED),A  CLEAR CURSOR SAVED FLAG
         LD        HL,ISTASC  SELECT PLATO/ASCII KEYBOARD 
         LD        (KBAADR),HL
         LD        HL,CTLADR.P   SELECT PLATO CTL TBL 
         LD        (CTLADR),HL
         LD        HL,ESCADR.P   SELECT PLATO ESC SEQ TBL 
         LD        (ESCADR),HL
         LD        HL,00      NO GRAPH MODE SCREEN BIAS 
         LD        (BIAS),HL
         LD        A,01       DO NOT SCALE
         LD        (SCALEFG),A
         LD        L,00       SET HOR/MEM0/SIZE1/FWD
         CALL      R.CCR
         LD        L,1AH      SET ALPHA/REWRITE MODE
         JP        R.MODE 
 
PINIT.3  EQU       *
         LD        HL,00D0H 
         CALL      R.XMIT    SEND ECHO
         JR        PINIT.2
 
 
*TERMINAL READY MESSAGE 
TRMRDY   EQU       *
         HEX       54,05,12,0D
         HEX       09,0E,01,0C
         HEX       2D,52,05,01
         HEX       04,19
 
*VERSION (CHANGE WITH NEW PRODUCTION BINARY)
VER      EQU       *
         HEX       2D,1B,1D    02 
         HEX       3F,00
 
* BLOCK FAILURE MESSAGE 
BLKFAIL  EQU       *
         HEX       42,0C,0F,03,0B,2D
         HEX       46,01,09,0C,15,12,05,3F,00 
 
VERSION  DEFB      02       CHANGE WITH NEW PRODUCTION BIN. 
         EJECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
* 
*        LONG INTERVAL INTERRUPT PROCESSOR
*        INTERRUPTS OCCUR AT 17.5 MILLISECOND INTERVALS 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
LINT     EQU       *
         PUSH      AF 
         PUSH      BC 
         PUSH      DE 
         PUSH      HL 
 
         LD        A,(M.ENAB) CLEAR LONG INTERVAL INT.
         LD        B,A
         RES       2,A
         OUT       (INTMSK),A 
         LD        A,B        REENABLE LONG INTERVAL INT. 
         OUT       (INTMSK),A 
 
         LD        A,(USERFLG)  IS A USER PROGRAM RUNNING 
         OR        A
         JR        Z,LINT1    JUMP IF NO
 
         LD        A,(MODE)   YES, IS THIS PLATO OPERATION
         RLCA 
         JP        NC,R.INIT  NO, SIMULATE A SHORT RESET
 
LINT1    EQU       *
 
         LD        HL,(M.CLOCK) AND INCREMENT (M.CLOCK) 
         INC       HL 
         LD        (M.CLOCK),HL 
 
         LD        HL,BLINKCTR  CHECK BLINK COUNTER 
         LD        A,(HL) 
         OR        A
         JP        Z,RETURN 
         DEC       (HL)       DECREMENT IF NOT ZERO 
         JP        R.RETURN 
         EJECT
         EJECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
* 
*        ASCII COMMUNICATIONS PORT INTERRUPT PROCESSOR
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
ASCCRDY  EQU       *          CHARACTER READY ENTRY 
         PUSH      AF           (PARITY MAY BE GOOD OR BAD) 
         PUSH      BC 
         PUSH      DE 
         PUSH      HL 
 
         IN        A,(ASCDATI)  INPUT DATA
         LD        C,A
         CALL      ERRCHK     CALL ERROR PROTOCOL HANDLER 
         JP        C,R.RETURN EXIT IF CHAR TO BE IGNORED
 
ASCCRDY1 EQU       *
         LD        A,(LOC.RMT)  THROW AWAY CHARACTER
         OR        A              IF LOCAL
         JP        NZ,RETURN
         RES       7,C        CLEAR PARITY BIT
         LD        HL,RXBUF   RECEIVE BUFFER ADDRESS
         LD        A,0FFH     LOAD MASK FOR INDEX 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         CP        (HL)       TEST FOR FULL BUFF
         JR        Z,ASCCRDY2 JUMP IF FULL
         INC       (HL)       INCREMENT DIFF COUNT
         INC       HL         STEP TO INPUT INDEX 
         AND       (HL)       INDEX TO REG A
         INC       (HL)       INCREMENT INPUT INDEX 
         INC       HL         STEP TO START OF
         INC       HL            STORE AREA 
         LD        E,A        ADD INDEX 
         LD        D,00 
         ADD       HL,DE
         LD        (HL),C     STORE DATA
         LD        HL,M.JOBS  INCREMENT (M.JOBS)
         INC       (HL) 
         JP        R.RETURN 
 
ASCCRDY2 EQU       *
         LD        A,(MODE)   SEND NAK AND ABORT RECEIVE
         RLCA                   IF PLATO MODE 
         CALL      C,SENDNAK
         JP        RETURN 
 
ASCERR   EQU       *          RECEIVE CHARACTER ERROR ENTRY 
         PUSH      AF           (OVERRUN OR FRAMING ERROR)
         PUSH      BC 
         PUSH      DE 
         PUSH      HL 
 
         IN        A,(ASCDATI)  INPUT DATA
         LD        C,A        SAVE CHARACTER IN C 
         LD        A,30H      CLEAR ERROR FLAGS 
         OUT       (ASCCTRL),A
         LD        A,(MODE)   CHECK MODE
         RLCA 
         JR        NC,ASCERR1 
         CALL      ERR.P      PLATO MODE ERROR
         JR        ASCERR2
ASCERR1  EQU       *
         CALL      ERR.A      ASCII MODE ERROR
ASCERR2  EQU       *
         JR        NC,ASCCRDY1  SAVE CHAR IF FLAGGED OK 
         JP        RETURN     OTHERWISE IGNORE IT 
 
ASCCREQ  EQU       *          CHARACTER REQUEST ENTRY 
         PUSH      AF 
         PUSH      BC 
         PUSH      DE 
         PUSH      HL 
 
         LD        HL,TXBUF   LOAD ADDRESS OF TRANSMIT BUFF 
         XOR       A          TEST FOR EMPTY
         OR        (HL)          BUFFER 
         JR        Z,ASCCREQ1 JUMP IF BUFFER EMPTY
 
         DEC       (HL)       DECREMENT DIFFERENCE COUNT
         INC       HL         STEP TO 
         INC       HL            OUT INDEX
         LD        A,07       LOAD MASK FOR INDEX 
         AND       (HL)       GET INDEX 
         INC       (HL)       INCREMENT INDEX 
         INC       HL         STEP TO STORE AREA
         LD        E,A        ADD INDEX TO
         LD        D,00          START OF STORE AREA
         ADD       HL,DE
         LD        A,(HL)     LOAD DATA TO TRANSMIT 
         OUT       (ASCDATO),A  OUTPUT DATA 
         JP        RETURN 
 
ASCCREQ1 EQU       *
         LD        A,28H      TURN OFF CHARACTER REQUEST INT
         OUT       (ASCCTRL),A
         XOR       A          CLEAR ASCII TRANSMIT BUSY FLAG
         LD        (TXBUSY),A 
         JP        RETURN 
 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
ASCXTCHG EQU       *          CHANGE OF CTS OR DCD, OR BREAK
         PUSH      AF 
         PUSH      BC 
         PUSH      DE 
         PUSH      HL 
 
         LD        A,10H      CLEAR EXT/STATUS INTERRUPT
         OUT       (ASCCTRL),A
         JP        RETURN 
         EJECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        KEY BOARD INTERRUPT PROCESSOR
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
KYBD     EQU       *
         PUSH      AF 
         PUSH      BC 
         PUSH      DE 
         PUSH      HL 
         SPACE     1
         IN        A,(KBDATA)     INPUT KEY BOARD DATA
         LD        L,A            LOAD KEYBOARD DATA
         LD        H,40H            OP CODE AND CATAGORY
         LD        A,(MODE)   CLEAR CTRL BIT IF PLATO MODE
         RLCA 
         JR        NC,KYBD1 
         RES       7,L
KYBD1    EQU       *
         LD        A,(SCOPYFLG)  IS SCREEN COPY ACTIVE
         OR        A
         JR        NZ,KYBD2   JUMP IF YES 
 
* DO A SCREEN COPY IF SHIFT-PRINT IS PRESSED. 
* OTHERWISE, JUST TRANSMIT THE CHARACTER. 
         LD        A,L        NO, IS KEY = SHIFT-PRINT
         CP        3FH
         JR        NZ,KYBD3   JUMP IF NO
 
         LD        A,01       SET SCREEN COPY ACTIVE FLAG 
         LD        (SCOPYFLG),A 
         EI                   ENABLE INTERRUPTS 
         CALL      G.PRINT    DO THE SCREEN COPY
         DI                   DISABLE INTERRUPTS
         XOR       A          CLEAR SCREEN COPY ACTIVE FLAG 
         LD        (SCOPYFLG),A 
         JR        RETURN 
 
* TURN OFF SCREEN COPY IF STOP OR SHIFT-STOP IS PRESSED.
* OTHERWISE IGNORE THE KEY. 
KYBD2    EQU       *
         LD        A,L        IS KEY = STOP OR SHIFT-STOP 
         RES       5,A
         CP        1AH
         JR        NZ,RETURN  NO, IGNORE KEY
 
         LD        A,01       YES, SET SCREEN COPY TURNOFF
         LD        (TURNOFF),A  FLAG AND TRANSMIT THE KEY 
         LD        A,(MODE)   CHECK MODE
         RLCA 
         JR        NC,RETURN  TRANSMIT ONLY IF PLATO MODE 
 
KYBD3    EQU       *
         CALL      FIFO.ST      AND STORE FOR TRANSMIT
         JR        RETURN 
         SPACE     4
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        TOUCH PANEL INTERRUPT PROCESSOR
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
TP       EQU       *
         PUSH      AF 
         PUSH      BC 
         PUSH      DE 
         PUSH      HL 
         SPACE     1
         IN        A,(TPDATA)     INPUT TOUCH PANEL DATA
         LD        L,A            LOAD TOUCH PANEL DATA 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        H,41H            OP CODE AND CATAGORY
         CALL      FIFO.ST      AND STORE FOR TRANSMIT
         LD        A,01 
         OUT       (MISCTL),A 
         JR        RETURN         RETURN TO INTERRUPTED PROCES
         EJECT     EXTERNAL INTERRUPT PROCESSOR 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        EXTERNAL CHANNEL INTERRUPT PROCESSOR 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
EXTI     EQU       *
         PUSH      AF 
         PUSH      BC 
         PUSH      DE 
         PUSH      HL 
* 
         LD        HL,(M.EXTPA)   LOAD PROCESSOR ADDR.
         LD        A,L        TEST FOR ZERO 
         OR        H
         JR        Z,EXTI0
         JP        (HL)       NONZERO, GO TO USER ROUTINE 
* 
EXTI0    EQU       *
         LD        A,(EXT.IN)     LOAD EXTERNAL DEVICE ADDRESS
         LD        C,A
         AND       1CH            TEST FOR SERIAL OR PARALLEL 
         JR        Z,EXTI1
         SET       5,C        SELECT PARALLEL CHANNEL 
         JR        EXTI2
* 
EXTI1    EQU       *
         SET       4,C        SELECT SERIAL CHANNEL 
EXTI2    EQU       *
         IN        L,(C)          INPUT FROM EXTERNAL CHANNEL 
         LD        H,82H          LOAD OP CODE AND USER/PLATO 
         CALL      FIFO.ST      AND STORE FOR TRANSMIT
         SPACE     4
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        RESTORE ALL REGISTERS AND ENABLE INTERRUPTS
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
RETURN   EQU       *
         POP       HL 
         POP       DE 
         POP       BC 
         POP       AF 
         EI                       ENABLE SYSTEM INTERRUPTS
         RETI 
         EJECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
* 
*        STORE DATA FROM INPUT DEVICES (KEYBOARD, TOUCH 
*        PANEL OR EXTERNAL DEVICE) INTO EITHER THE TRANSMIT 
*        BUFFER OR THE USER BUFFER DEPENDING ON (M.KSW) 
* 
*        ON ENTRY, DATA IS IN HL
*          H7=1 FOR CATEGORY 2 DATA (EXT) 
*          H6=1 FOR CATEGORY 1 DATA (KB OR TP)
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
FIFO.ST  EQU       *
         LD        A,0C0H     GET CATEGORY BITS 
         AND       H
         RLCA                 PUT CATEGORY BITS IN LOWER
         RLCA                     BITS
         LD        B,A            AND SAVE IN B REGISTER
         LD        A,(M.KSW)  CHECK FOR TRANSMIT/USER 
         AND       B
         JP        Z,R.XMIT 
 
US.STOR  EQU       *
         LD        E,L        DE = HL WITH UPPER BITS CLEAR 
         LD        A,H
         AND       03H
         LD        D,A
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        HL,USBUF 
         LD        A,07H      TEST FOR FULL BUFFER
         CP        (HL) 
         RET       Z          BUFFER FULL, RETURN TO CALLER 
 
         INC       (HL)       NOT FULL, INCREMENT DIFF CNTR 
         INC       HL         POINT TO INPUT POINTER
         AND       (HL)       GET LOWER BITS
         RLCA                   AND SET FOR TWO BYTE ADDRESS
         INC       (HL)       INCREMENT POINTER 
         LD        B,0        PUT INDEX IN BC 
         LD        C,A
         INC       HL         POINT TO START OF BUFFER AREA 
         INC       HL 
         ADD       HL,BC      INDEX INTO BUFFER 
         LD        (HL),E     STORE DATA LOWER BITS 
         INC       HL 
         LD        (HL),D     STORE DATA UPPER BITS 
         RET
         EJECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
* 
*        MAIN IDLE LOOP 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
IDLE     EQU       *
         XOR       A          FLAG USER PROGRAM NOT RUNNING 
         LD        (USERFLG),A
         CALL      CHKSUM     CHECKSUM MEMORY DURING IDLE 
         JR        Z,IDLE1
         JR        BLOCKF     NOP THIS FOR EXP TESTING
IDLE1    EQU       *
         LD        A,(MODE)   TEST FOR OPERATING MODE 
         RLCA 
         JP        NC,AIDLE   ASCII IDLE IF BIT 7 CLEAR 
 
**********
* PLATO OPERATIONS IDLE LOOP
**********
PIDLE    EQU       *
         CALL      R.EXEC     TEST FOR RECEIVE OR XMIT DATA 
         JR        IDLE       LOOP TO IDLE
 
**********
* DISPLAY .BLOCK FAILURE. MESSAGE 
* TERMINAL MUST BE RESET TO RECOVER 
**********
BLOCKF   EQU       *
         LD        HL,400 
         CALL      R.OUTX 
         LD        HL,256 
         CALL      R.OUTY 
         LD        HL,BLKFAIL 
         CALL      R.CHARS
BLOCKF1  JR        BLOCKF1    HANG
         EJECT
**********
* EXECUTE RECEIVE DATA UNTIL RECEIVE BUFFER IS EMPTY. 
**********
EXEC     EQU       *
         LD        A,(EREG)   CHECK TIME OUT
         AND       04           IF COMM ERROR STATE 
         CALL      NZ,TIMOUT
         CALL      CHECKSWS   CHECK FRONT PNL SWS FOR CHANGE
         LD        A,(MODE)   CHECK MODE
         RLCA 
         JR        NC,EXEC3   NO TEST IF ASCII MODE 
         LD        B,3
EXEC1    EQU       *
         CALL      CARRIER
         JR        NC,EXEC3   IF CARRIER PRESENT
         LD        HL,0       WAIT ABOUT HALF A SECOND
EXEC2    EQU       *
         DEC       HL 
         LD        A,L
         OR        H
         JR        NZ,EXEC2 
         DJNZ      EXEC1   SEE IF CARRIER IS BACK ON
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        (RESETFLG),A  FORCE A FULL TIMESHARE 
         JP        R.INIT         MODE INIT AFTER 3 SECONDS 
 
EXEC3    EQU       *
         LD        A,(M.JOBS) TEST FOR RECEIVE DATA 
         OR        A
         RET       Z          EXIT IF NO RECEIVE DATA 
         CALL      PROCESS
         JR        EXEC3
 
**********
* FETCH A BYTE FROM THE RECEIVE BUFFER. 
* ON EXIT, THE BYTE IS IN THE C-REGISTER. 
**********
GJOB     EQU       *
         LD        HL,M.JOBS  DECREMENT (M.JOBS)
         DEC       (HL) 
         LD        HL,RXBUF 
         DEC       (HL)       DECREMENT DIFF COUNT
         INC       HL         STEP TO OUT 
         INC       HL 
         LD        A,0FFH     MASK OUT INDEX WITH BUFF LEN
         AND       (HL)       DATA IN A REG 
         INC       (HL)       INCREMENT OUT INDEX 
         INC       HL         BEGIN OF DATA STORE 
         LD        E,A
         LD        D,00 
         ADD       HL,DE
         LD        C,(HL)     DATA TO C REGISTER
         RET
         EJECT
**********
* PROCESS A CHARACTER TAKEN FROM RECEIVE BUFFER 
**********
PROCESS  EQU       *
         CALL      R.GJOB     GET NEXT CHAR 
 
**********
* EXECUTE CHARACTER IN THE C-REGISTER 
**********
XJOB     EQU       *
         RES       7,C        CLEAR UPPER BIT OF CHARACTER
         PUSH      BC         SAVE CHARACTER
         CALL      ESCCTL     CHECK FOR ESC SEQ OR CTL CODE 
         POP       BC         GET SAVED CHARACTER 
         JR        C,XJOB2    JUMP IF ESC SEQ OR CTL CODE 
 
         LD        A,(CMODE)  TEST FOR COMMAND MODE ACTIVE
         OR        A
         JR        Z,XJOB.DAT JUMP IF NOT 
 
XJOB.CMD EQU       *
         LD        HL,SELECT.C-2  SELECT COMMAND TABLE
         JR        XJOB1       AND JUMP VIA (CMODE) 
 
XJOB.DAT EQU       *
         LD        A,(BYPASS) CHECK BYPASS
         OR        A
         RET       NZ         IGNORE DATA IF BYPASS ON
 
         LD        A,(MODE)   JUMP VIA (MODE) 
         ADD       A,A
         LD        HL,SELECT.D SELECT DATA TABLE
 
XJOB1    EQU       *
         LD        E,A        INDEX INTO SELECTED TABLE 
         LD        D,0
         ADD       HL,DE      SELECT.C OR SELECT.D
         LD        E,(HL)     GET JUMP ADDRESS
         INC       HL 
         LD        D,(HL) 
         EX        DE,HL
         PUSH      BC         SAVE CHARACTER
         CALL      JMPHL      EXECUTE COMMAND OR DATA 
         POP       BC         GET SAVED CHARACTER 
XJOB2    EQU       *
         LD        A,(CPRINTFG)  CHECK FOR COMM PRINT ACTIVE
         OR        A
         JP        NZ,CPRINT  OUTPUT CHARACTER TO PRINTER 
         RET
 
JMPHL    EQU       *
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         JP        (HL)       JUMP VIA HL 
 
SELECT.C EQU       *          COMMAND JUMP TABLE
         DEFW      LDC
         DEFW      SSF
         DEFW      LDE
         DEFW      LDA
         DEFW      EXT
         DEFW      COLOR
 
SELECT.D EQU       *          DATA JUMP TABLE 
         DEFW      APOINT     MODE 0
         DEFW      GRAPH      MODE 1
         DEFW      MEMORY     MODE 2
         DEFW      CHARACT    MODE 3
         DEFW      ABLOCK     MODE 4
         DEFW      MODE5      MODE 5
         DEFW      MODE6      MODE 6
         DEFW      MODE7      MODE 7
         DEFW      TEMP       MODE 8
 
 
**********
* CHECK FOR CHANGE IN TALK/DATA SWITCH AND UPDATE 
* COMM CHANNEL DTR SIGNAL ACCORDINGLY.
**********
CHECKSWS EQU       *
         LD        HL,XCOMMSW POINT TO OLD SWITCH SETTING 
         IN        A,(COMMSW) GET NEW SWITCH SETTING
         LD        C,A
         LD        A,(HL)     GET OLD SWITCH SETTING
         LD        (HL),C     SAVE NEW SWITCH SETTING 
         XOR       C          COMPARE 
         BIT       3,A
         RET       Z          EXIT IF NO CHANGE OF TALK/DATA
 
         BIT       2,C
         RET       NZ         IGNORE TALK/DATA IF CONST DTR 
 
         LD        HL,ASCPKG+5 POINT AT REG. 5 CONTROL BYTE 
         RES       7,(HL)     CLEAR DTR BIT 
         LD        A,0FFH     CLEAR DTR AND ERR LIGHTS
         OUT       (PNLLTS),A 
         BIT       3,C        SET DTR BIT IF IN DATA POS. 
         JR        Z,CHKSWS1
         SET       7,(HL)     SET DTR BIT 
         LD        A,0DFH     SET DTR LIGHT, CLEAR ERR LIGHT
         OUT       (PNLLTS),A 
CHKSWS1  EQU       *
         JP        ASCSETUP   SET UP SIO
         EJECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
* CHECK FOR AND EXECUTE ESCAPE SEQUENCES OR CONTROL CODES.
* ON ENTRY, THE CHARACTER TO BE EXECUTED IS IN THE C-REG. 
* ON EXIT, CARRY IS SET IF CHARACTER WAS A CONTROL CODE 
* OR THE SECOND CHARACTER OF AN ESCAPE SEQUENCE.
* OTHERWISE CARRY IS CLEAR ON EXIT. 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
ESCCTL   EQU       *
         LD        A,(G.ESC)  TEST FOR ESCAPE FLAG SET
         OR        A
         JR        Z,CTLCK    JUMP IF NOT SET 
         XOR       A          CLEAR FLAG
         LD        (G.ESC),A
 
EX.ESC   EQU       *
         LD        HL,(ESCADR)  SEARCH FOR ESC SEQ MATCH
         JR        CTLEXEC
 
CTLCK    EQU       *
         LD        A,C        TEST FOR CONTROL CODE 
         CP        20H
         RET       NC         NOT A CTL CODE, RETURN
 
         XOR       A
         LD        (CMODE),A  CLEAR COMMAND MODE
         LD        (NBYTES),A CLEAR NBYTES COUNTER
 
EX.CTL   EQU       *
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        HL,(CTLADR) SEARCH FOR CONTROL CODE MATCH
 
CTLEXEC  EQU       *
         CALL      SEARCH     EXECUTE CHAR
         SCF                  SET CARRY FLAG
         RET
* 
SEARCH   EQU       *
         LD        A,(HL)     IF FF REACHED, NO MATCH 
         CP        0FFH 
         RET       Z          IGNORE CHAR IF NOT FOUND
 
SEARCH1  EQU       *
         CP        C
         JR        Z,MATCH    CHECK FOR CHAR MATCH
         INC       HL         CONTINUE SEARCHING
         INC       HL 
         INC       HL 
         JR        SEARCH 
 
MATCH    EQU       *
         INC       HL 
         LD        E,(HL) 
         INC       HL         MATCH, JUMP TO EXECUTE COMMAND
         LD        D,(HL) 
         EX        DE,HL
         LD        DE,M.CCR 
         JP        (HL) 
         EJECT
**********
* CONVERT KEYBOARD CODE IN E REG TO ASCII CODE IN C REG.
* ON EXIT, THE ZERO FLAG IS SET IF THE KEY IS UNDEFINED.
* FOR DEFINED KEYS, THE ZERO FLAG IS CLEAR. 
**********
KBCON    EQU       *
         LD        D,00 
         LD        HL,(KBAADR)
         ADD       HL,DE
         LD        A,(HL) 
         LD        C,A
         CP        0FFH 
         RET
* 
ISTASC   EQU       *
         HEX       30,31,32,33  0X
         HEX       34,35,36,37
         HEX       38,39,26,60
         HEX       0A,5E,2B,2D
         HEX       13,04,07,08  1X
         HEX       7B,0B,0D,1A
         HEX       02,12,01,03
         HEX       7D,0C,FF,FF
         HEX       3C,3E,5B,5D  2X
         HEX       24,25,5F,7C
         HEX       2A,28,40,27
         HEX       1C,5C,23,7E
         HEX       17,05,14,19  3X
         HEX       7F,09,1E,18
         HEX       0E,1D,11,16
         HEX       00,0F,FF,FF
         HEX       20,61,62,63  4X
         HEX       64,65,66,67
         HEX       68,69,6A,6B
         HEX       6C,6D,6E,6F
         HEX       70,71,72,73  5X
         HEX       74,75,76,77
         HEX       78,79,7A,3D
         HEX       3B,2F,2E,2C
         HEX       1F,41,42,43  6X
         HEX       44,45,46,47
         HEX       48,49,4A,4B
         HEX       4C,4D,4E,4F
         HEX       50,51,52,53  7X
         HEX       54,55,56,57
         HEX       58,59,5A,29
         HEX       3A,3F,21,22
         EJECT
**********
* 'THE FOLLOWING ROUTINE TRANSFERS DATA IN HL TO THE
* TRANSMIT BUFFER.  KEYBOARD DATA IS CONVERTED TO ASCII.
**********
TX.STOR  EQU       *
         LD        E,L       SAVE DATA IN DE
         LD        D,H
         ADD       HL,HL      IS THIS KYBD DATA 
         LD        A,07H
         AND       H
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         JR        NZ,TX.STOR3  NO, JUMP
 
         CALL      KBCON     CONVERT CHAR TO ASCII IN C 
         JP        NZ,XMIT.1  SEND THE CHAR IF DEFINED KEY
         RET                  EXIT FOR UNDEFINED KEYS 
 
TX.STOR3 EQU       *         NOT KYBD DATA, SO
         PUSH      DE 
         LD        C,1BH     SEND ESC CODE
         CALL      XMIT.1 
         POP       DE 
         LD        A,3FH     SEND LOWER 6 BITS
         AND       E
         ADD       A,40H
         LD        C,A
         PUSH      DE 
         CALL      XMIT.1 
         POP       HL         SEND UPPER 4 BITS 
         ADD       HL,HL
         ADD       HL,HL
         LD        A,H
         AND       0FH
         ADD       A,40H
         LD        C,A
         CALL      XMIT.1 
         RET                 AND EXIT.
 
**********
* STORE CHAR FROM C-REGISTER INTO TRANSMIT BUFFER.
**********
XMIT.1A  EQU       *          GRAPHIC/TIMESHARE MODE ENTRY
         LD        A,(LOC.RMT)
         OR        A
         RET       NZ         JUST EXIT IF LOCAL
 
XMIT.1   EQU       *          PLATO MODE ENTRY
         LD        HL,TXBUF   TEST FOR FULL BUFFER
         LD        A,07H
         CP        (HL) 
         JR        C,XMIT.1   JUMP IF FULL
 
         INC       (HL)       NOT FULL, INC DIFF CNT
         INC       HL         POINT TO INPUT INDEX
         AND       (HL)         GET IT
         INC       (HL)         AND INCREMENT IT
         INC       HL         POINT TO BUFFER AREA
         INC       HL 
         LD        E,A        ADD THE INPUT INDEX 
         LD        D,00H
         ADD       HL,DE
         LD        A,C        CALCULATE PARITY ON XMIT CHAR 
         OR        A
         JP        PE,XMIT.1B 
         SET       7,C        ASSUME EVEN PARITY
XMIT.1B  EQU       *
         LD        A,(MODE)   CHECK MODE
         RLCA 
         JR        C,XMIT.1E  JUMP IF PLATO 
         LD        A,(PARITY)  IS PARITY SELECTED 
         BIT       1,A
         JR        NZ,XMIT.1C  JUMP IF NO 
         BIT       0,A         YES, IS IT EVEN OR ODD 
         JR        Z,XMIT.1E  JUMP IF EVEN
         JR        XMIT.1D    ODD 
XMIT.1C  EQU       *
         IN        A,(COMMSW) CHECK EVEN/ODD
         BIT       4,A
         JR        NZ,XMIT.1E  JUMP IF EVEN 
XMIT.1D  EQU       *
         LD        A,C        CHANGE TO ODD PARITY
         XOR       80H
         LD        C,A
XMIT.1E  EQU       *
         LD        (HL),C     STORE DATA IN TXBUF 
         LD        HL,TXBUSY  EXIT IF ASCII TRANSMITTER BUSY
         BIT       0,(HL) 
         RET       NZ 
         DI                   TRANSMITTER IS IDLE, SO SET 
         SET       0,(HL)     BUSY FLAG AND START TRANSMIT
         CALL      ASCCREQ
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         RET
         EJECT
**********
* ROUTINE TO CHECKSUM RAM DURING IDLE TIME. 
* ON EXIT, ZERO FLAG IS SET IF CHECKSUM IS PROCEEDING OK. 
* IF THERE IS A CHECKSUM ERROR, THE ZERO FLAG IS CLEAR. 
**********
CHKSUM   EQU       *
         LD        DE,(CKSUMADD)  GET CURRENT ADDRESS 
         LD        HL,(CKSUMWC)   GET CURRENT WORD COUNT
         LD        A,(CKSUM)     GET CURRENT CHECKSUM 
         LD        C,A
         LD        B,100        SET COUNTER 
 
CHKSUM1  EQU       *
         LD        A,L        ARE WE DONE WITH THIS PART
         OR        H
         JR        Z,CHKSUM4  YES, JUMP 
 
         LD        A,(DE)     ADD BYTE TO CHECKSUM
         ADD       A,C
         LD        C,A
         INC       DE 
         DEC       HL 
         DJNZ      CHKSUM1    LOOP IF COUNT NOT EXPIRED 
 
CHKSUM2  EQU       *
         LD        (CKSUMADD),DE  SAVE CURRENT ADDRESS
         LD        (CKSUMWC),HL   SAVE CURRENT WORD COUNT 
         LD        A,C        SAVE CURRENT CHECKSUM 
         LD        (CKSUM),A
         XOR       A          SET ZERO FLAG 
         RET
 
CHKSUM4  EQU       *
         LD        HL,(CKSUMTAD)  GET CURRENT TABLE ADDRESS 
         LD        E,(HL)     DE = NEW ADDRESS
         INC       HL 
         LD        D,(HL) 
         INC       HL 
         LD        A,(HL)     BA = NEW WORD COUNT 
         INC       HL 
         LD        B,(HL) 
         INC       HL 
         LD        (CKSUMTAD),HL  SAVE PLACE IN TABLE 
         LD        L,A        HL = BA = NEW WORD COUNT
         LD        H,B
         OR        B          IS BYTE COUNT = 0 
         JR        NZ,CHKSUM2  NO, CONTINUE 
 
CHKSUM5  EQU       *          END OF TABLE FOUND
         LD        A,(CHECKSUM)  DOES CHECKSUM AGREE
         CP        C
         PUSH      AF         SAVE TEST RESULT
         CALL      CHKSUM.I   REINITIALIZE
         POP       AF         GET SAVED TEST RESULT 
         RET
 
CHKSUM.I EQU       *
         XOR       A          INITIALIZE FOR CHECKSUM 
         LD        C,A          COMPUTATION 
         LD        (CKSUM),A
         LD        HL,(CKSUMTBL)
         LD        (CKSUMTAD),HL
         JR        CHKSUM4
         EJECT
**********
* THIS ROUTINE PERFORMS ERROR RECOVERY PROTOCOL DURING
* TRANSFERS FROM THE DSN NETWORK TO THE TERMINAL. 
* THE PROTOCOL FOR ASCII MODES (TIMESHARE OR GRAPHIC) MERELY
* CHECKS FOR PARITY ERRORS AND TURNS ON THE ERR LIGHT UNTIL 
* THE NEXT CHARACTER IS RECEIVED IF THERE IS A PARITY ERROR 
* AND PARITY CHECKING IS SELECTED.  IN TIMESHARE MODE, AN 
* ERROR CHARACTER IS DISPLAYED AS A PAD CHARACTER.  IN PLATO
* MODE, THE PROTOCOL UTILIZES EVEN PARITY ON EACH CHARACTER 
* TRANSFERRED AND ALSO A MODULO 96 WORD COUNT ON THE
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
* BLOCK.  'THE FIRST CHARACTER RECEIVED IS AN ACK CODE
* FOLLOWED BY A WORD COUNT BYTE FOLLOWED BY THE REST OF 
* THE DATA.  'THE TERMINAL SENDS AN ACK,WC AFTER EACH 20TH
* BYTE RECEIVED UNLESS A PARITY ERROR HAS OCCURRED IN WHICH 
* CASE A NAK,WC IS SENT IMMEDIATELY.
* 'THE C REGISTER CONTAINS THE DATA BYTE ON ENTRY.
* ON EXIT, CARRY=1 SAYS TO DISCARD THE CHARACTER
*          CARRY=0 SAYS TO UTILIZE THE CHARACTER. 
**********
ERRCHK   EQU       *
         LD        A,(MODE)   CHECK MODE
         RLCA 
         JR        C,ERRCHKP  JUMP IF PLATO 
 
         LD        A,(PARITY) ASCII, SO CHECK PAR/NO PAR
         BIT       1,A
         JR        NZ,ERRCHK2 JUMP IF NO PAR
         BIT       0,A        PAR, SO CHECK EVEN/ODD
         LD        A,C        PUT CHAR IN A 
         JR        Z,ERRCHK1  JUMP IF EVEN PAR
         XOR       80H        TOGGLE PARITY BIT 
ERRCHK1  EQU       *
         OR        A
         JP        PO,ERR.A   JUMP IF PARITY ERROR
ERRCHK2  EQU       *
         LD        A,C        PARITY OK...
         RES       7,A
         CP        7FH        IS CHARACTER A RUBOUT 
         JR        NZ,E006    NO, CONTINUE
         LD        A,0DFH     TURN OFF ERR LIGHT
         OUT       (PNLLTS),A 
         LD        A,(MODE)   CHECK FOR ALPHA MODE
         XOR       3
         RET       NZ         EXIT (USE CHAR) IF NOT ALPHA
         SCF
         RET                  EXIT(IGNORE CHARACTER)
 
ERR.A    EQU       *          ASCII MODE ERROR ENTRY
         LD        A,(TGMODE) CHECK TIMESHARE/GRAPHIC 
         OR        A
         JR        NZ,ERR.P   JUMP IF GRAPHIC MODE
         LD        C,7FH      TS,SO CHANGE ERROR CHAR TO PAD
 
ERR.P    EQU       *          PLATO MODE ERROR ENTRY
         LD        A,0DEH     TURN ON ERR LIGHT 
         OUT       (PNLLTS),A 
         LD        HL,EREG    POINT TO ERROR PROTOCOL FLAGS 
         RES       6,(HL)     CLEAR ACK FLAG
         OR        A          CLEAR CARRY 
         BIT       0,(HL)     TEST STATE 0
         RET       NZ         USE CHAR IF STATE = 0 
         BIT       1,(HL)     TEST STATE 1
         CALL      NZ,SENDNAK SEND NAK,M AND SET STATE 2 IF 
         SCF                      STATE=1 
         RET                  EXIT(DISCARD CHARACTER) 
 
ERRCHKP  EQU       *          PLATO MODE ERROR PROTOCOL 
         LD        A,C
         OR        A
         JP        PO,ERR.P   JUMP IF PARITY ERROR
 
         LD        HL,EREG    POINT TO ERROR CONTROL FLAGS
         LD        A,06H     IF CHAR=ACK THEN 
         CP        C
         JR        NZ,E001
         SET       6,(HL)     SET ACK FLAG
         SCF
         RET                  AND EXIT(DISCARD) 
 
E001     EQU       *
         BIT       0,(HL)     ELSE IF STATE=0 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         JR        Z,E100       (NON ERROR CONTROL) THEN
         BIT       6,(HL)     IF ACK FLAG=1 THEN
         JR        Z,E006 
 
E002     EQU       *
         RES       6,(HL)     CLEAR ACK FLAG
         LD        A,C
         RES       7,A
         SUB       20H
         RET       C          EXIT(DISCARD) IF CTRL CHAR
         LD        (MREG),A      THEN SAVE BIASED CHAR
         LD        (NREG),A      AT M AND N 
         LD        (HL),02H   SET STATE=1 
         LD        A,0DFH     TURN OFF ERR LIGHT
         OUT       (PNLLTS),A 
         SCF                  AND EXIT(DISCARD) 
         RET
 
E006     EQU       *
         LD        A,0DFH     TURN OFF ERR LIGHT
         OUT       (PNLLTS),A 
         OR        A          CLEAR CARRY 
         RET                  EXIT(USE CHAR)
 
E100     EQU       *
         BIT       1,(HL)     IF NOT STATE 1 THEN JUMP
         JR        Z,E200 
 
         BIT       6,(HL)     IF ACK FLAG=1 THEN
         JR        Z,E105 
         RES       6,(HL)     CLEAR ACK FLAG
         LD        A,C
         SUB       20H          SET N = CHAR-20H
         LD        (NREG),A 
         SCF                  EXIT(DISCARD) 
         RET
 
E105     EQU       *         ELSE 
         LD        A,(MREG)  IF N=M (NORMAL CASE) THEN
         LD        B,A
         LD        A,(NREG) 
         CP        B
         JR        NZ,E107
 
         INC       A           SET M AND N =
         CP        60H          N+1 MOD 96
         JR        NZ,E106
         XOR       A
E106     LD        (NREG),A 
         LD        (MREG),A 
         RES       7,(HL)     MARK AS OK CHAR 
         JR        E109 
 
E107     EQU       *         M<>N, SO 
         INC       A         SET N = N+1 MOD 96 
         CP        60H
         JR        NZ,E108
         XOR       A
E108     LD        (NREG),A 
         SET       7,(HL)     MARK AS DISCARD CHAR
 
E109     EQU       *         NOW TEST THE CHAR COUNTER. 
         LD        A,(E.CNTR) IF E.CNTR&lt;>1 THEN 
         DEC       A
         JR        NZ,E110
         LD        A,20       RESET IF = 0
E110     EQU       *
         LD        (E.CNTR),A   DECREMENT E.CNTR
         JR        NZ,E114
 
         PUSH      BC         COUNTER=0, SO 
         LD        C,06H     SEND ACK 
         CALL      XMIT.1 
         LD        A,(MREG)  SEND M+20H 
         ADD       A,20H
         LD        C,A
         CALL      XMIT.1 
         POP       BC 
 
E114     EQU       *
         LD        A,(HL)     PUT MARK IN CARRY FLAG
         RLCA 
         RET                 AND EXIT 
 
E200     EQU       *         ERROR STATE
         BIT       6,(HL)     TEST ACK FLAG 
         JP        NZ,E002    RESYNC IF SET 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         SCF                  EXIT(DISCARD) 
         RET
 
* PLATO COMMUNICATIONS ERROR STATE TIMER, 
* RESENDS NAK SEQUENCE EVERY 250 MS UNTIL ACK RECEIVED. 
TIMOUT   EQU       *
         LD        HL,(ECLOCK)  HAS TIMER EXPIRED 
         DEC       HL 
         LD        (ECLOCK),HL
         LD        A,L
         OR        H
         RET       NZ           NO, EXIT
 
* CALLABLE ROUTINE TO SEND NAK SEQUENCE AND SET ERROR STATE.
SENDNAK  EQU       *
         LD        A,0DEH     TURN ON ERR LIGHT 
         OUT       (PNLLTS),A 
         LD        HL,EREG
         BIT       0,(HL)    TEST FOR STATE 0 
         RET       NZ 
* 
         LD        (HL),04   ELSE SET ABORT STATE 
         LD        C,15H      SEND NAK
         CALL      XMIT.1 
         LD        A,(MREG)   SEND WC+20H 
         ADD       A,20H
         LD        C,A
         CALL      XMIT.1 
         LD        HL,300     RESET 250 MS TIMER
         LD        (ECLOCK),HL
         RET
         EJECT     PROCESS LDM COMMAND
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        LOAD MODE INSTRUCTION, (LDM) 
* 
*        LOAD TERMINAL OPERATING MODE 
* 
*        BIT 1     BULK ERASE 
* 
*        BIT 3     BIT 2
*        0         0              ERASE          WRITE INVERSE
*        0         1              WRITE          WRITE NORMAL 
*        1         0              ERASE          OVERSTRIKE ER
*        1         1              WRITE          OVERSTRIKE WR
* 
*        BITS 4-6  LOAD OPERATING MODE
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
MODESET  EQU       *          USER ENTRY POINT
         LD        A,L
         SRL       A          SET CARRY IF BULK ERASE 
         LD        (M.MODE),A STORE MODE BITS 
         CALL      C,BULKER   BULK ERASE IF CARRY SET 
         LD        A,(M.MODE) GET MODE BITS 
         RRCA 
         RRCA 
         AND       07H
         LD        C,A
         LD        A,(MODE)   INSERT THEM INTO MODE 
         AND       80H
         OR        C
         LD        (MODE),A 
         JP        CG.SEL     SELECT CHARACTER GENERATOR
 
MODESET1 EQU       *          LOCAL ENTRY TO SET W/E BITS 
         LD        A,(M.MODE) GET PRESENT MODE
         AND       0FCH       CLEAR WRITE/ERASE BITS
         OR        L          INSERT NEW WRITE/ERASE BITS 
         LD        (M.MODE),A STORE MODE BITS 
         LD        A,(MODE)   IF PLATO OPER. THEN 
         RLCA 
         JP        C,CG.SEL     SELECT CHARACTER GENERATOR
         RET
 
MODESET2 EQU       *          LOCAL ENTRY TO SET MODE BITS
         LD        A,(MODE)   GET OLD MODE BITS 
         AND       80H        CLEAR OLD MODE BITS 
         JR        Z,MODSET2A JUMP IF ASCII MODE
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         XOR       A          CLEAR BYPASS IN PLATO MODE
         LD        (BYPASS),A 
         LD        A,80H      GET BACK PLATO MODE BIT 
MODSET2A EQU       *
         OR        C          INSERT NEW MODE BITS
         LD        (MODE),A   STORE MODE BITS 
         ADD       A,A        SHIFT LEFT 2 AND SAVE IN C
         ADD       A,A
         LD        C,A
         LD        A,(M.MODE) UPDATE MODE BITS IN M.MODE
         AND       0E3H 
         OR        C
         LD        (M.MODE),A 
         RET
         EJECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        PROCESS LOAD COORDINATE , (LDC)
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
LDC      EQU       *
         CALL      GETXY      GET COORDINATES 
         PUSH      DE        SAVE Y COORDINATE. 
         CALL      R.OUTX     SET COORDINATES 
         POP       HL        GET Y COORDINATE.
         CALL      R.OUTY 
         RET
         EJECT     ECHO COMMAND PROCESSOR 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        PROCESS LOAD ECHO INSTRUCTION  (LDE) 
* 
*        BITS 1-7  ECHO CODE
* 
*        ECHO CODE =70            STATUS REQUEST. THE CONTENTS
*                                 M.TYPE IS LOADED AS THE ECHO
* 
*                  =71       REQUEST (M.SBTYPE) 
* 
*                  =72       REQUEST (M.LDFILE) 
* 
*                  =73       REQUEST (M.CONFIG) 
* 
* 
*                  =7A            SEND BACKOUT, TURN OFF DTR
* 
*                  =7B            SOUND AUDIBLE TONE AT TERMIN
* 
*                  =7C            TERMINAL ID CODE REQUEST. TH
*                                 TERMINAL SIXTEEN BIT ID CODE
*                                 LOADED INTO FOUR ECHO RESPON
* 
*                  =7D            REQUEST FOR TERMINAL FLAG 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
LDE      EQU       *
         CALL      GET3       GET NEXT 3 BYTES
         LD        A,L
         AND       7FH
         CP        70H            TEST FOR STATUS REQUEST 
         JR        NZ,LDE0
         SPACE     1
         LD        A,(M.TYPE)     LOAD TERMINAL TYPE CODE 
         SET       7,A            SET ECHO OP CODE
         LD        L,A            LOAD TYPE AS ECHO 
         LD        H,00       CATEGORY 3 SET TO 0 FOR 
         CALL      R.XMIT        TEST IN TX.STOR FOR XMIT 
         RET
* 
LDE0     EQU       *
         CP        7AH        TEST FOR TURN OFF 'D'T'R
         JR        NZ,LDE1
BACKOUT  EQU       *
         LD        HL,03FFH   SEND OUT BACK OUT CODE
         CALL      R.XMIT        TO PLATO 
BACKOUT1 EQU       *
         LD        A,01H      WAIT UNTIL BACKOUT IS SENT
         OUT       (ASCCTRL),A
         IN        A,(ASCSTAT)
         BIT       0,A
         JR        Z,BACKOUT1 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        A,05H      TURN OFF DTR AND RTS
         OUT       (ASCCTRL),A
         LD        A,28H
         OUT       (ASCCTRL),A
         LD        A,0FFH     TURN OFF DTR AND ERR LIGHTS 
         OUT       (PNLLTS),A 
         LD        B,6        WAIT 3 SECONDS
BACKOUT2 EQU       *
         LD        HL,0 
BACKOUT3 EQU       *
         DEC       HL 
         LD        A,L
         OR        H
         JR        NZ,BACKOUT3
         DJNZ      BACKOUT2 
         XOR       A          FORCE FULL TIMESHARE MODE INIT
         LD        (RESETFLG),A 
         JP        R.INIT 
* 
LDE1     EQU       *
         CP        7CH            TEST FOR ID REQUEST 
         JR        NZ,LDE2        NOT ID REQUEST
* 
         IN        A,(IDLO)       INPUT LOWER EIGHT BITS OF ID
         PUSH      AF 
         AND       0FH            MASK LOWER FOUR BITS
         OR        80H            INCLUDE OP CODE AND ID COUNT
         LD        L,A
         LD        H,00       CATEGORY 3 SET TO 0 FOR 
         CALL      R.XMIT        TEST IN TX.STOR FOR XMIT 
* 
         POP       AF 
         RRCA 
         RRCA 
         RRCA 
         RRCA 
         AND       0FH            MASK SECOND FOUR BITS 
         OR        90H            INCLUDE OP CODE AND ID COUNT
         LD        L,A
         LD        H,00       CATEGORY 3 SET TO 0 FOR 
         CALL      R.XMIT        TEST IN TX.STOR FOR XMIT 
* 
         IN        A,(IDUP)       INPUT UPPER EIGHT BITS
         PUSH      AF 
         AND       0FH            MASK LOWER FOUR BITS
         OR        0A0H           INCLUDE OP CODE  AND COUNT
         LD        L,A
         LD        H,00       CATEGORY 3 SET TO 0 FOR 
         CALL      R.XMIT        TEST IN TX.STOR FOR XMIT 
* 
         POP       AF 
         RRCA 
         RRCA 
         RRCA 
         RRCA 
         AND       0FH            MASK UPPER FOUR BITS
         OR        0B0H           INCLUDE OP CODE AND ID COUNT
         LD        L,A
         LD        H,00       CATEGORY 3 SET TO 0 FOR 
         CALL      R.XMIT        TEST IN TX.STOR FOR XMIT 
         RET
* 
LDE2     EQU       *
         CP        7BH            TEST FOR AUDIBLE
         JR        NZ,LDE3        NOT AUDIBLE 
 
* 
* BEEP THE BEEPER 
* 
ALARM    EQU       *
         LD        A,01 
         OUT       (MISCTL),A    SOUND AUDIBLE ALARM
         RET
* 
LDE3     EQU       *
         CP        7DH            TEST FOR TERMINAL FLAG REGIS
         JR        NZ,LDE4        NOT FLAG REQUSET
* 
         LD        HL,(MEMREG)    LOAD FLAG POINTER 
         LD        A,(HL)         LOAD CONTENTS OF FLAG REGIST
         AND       7FH              AND MASK LOWER SEVEN BITS 
* 
LDE4     EQU       *
         CP        71H       TEST FOR M.SBTYPE REQUEST
         JR        NZ,LDE5
 
         LD        A,(M.SBTYPE) 
         SET       7,A
         LD        L,A
         LD        H,00 
         CALL      R.XMIT 
         RET
 
LDE5     EQU       *
         CP        72H       TEST FOR M.LDFILE REQUEST
         JR        NZ,LDE6
 
         LD        A,(M.LDFILE) 
         SET       7,A
         LD        L,A
         LD        H,00 
         CALL      R.XMIT 
         RET
 
LDE6     EQU       *
         CP        73H       TEST FOR M.CONFIG REQUEST
         JR        NZ,LDE7
 
         LD        A,(M.CONFIG) 
         SET       7,A
         LD        L,A
         LD        H,00 
         CALL      R.XMIT 
         RET
 
LDE7     EQU       *
         OR        80H            SET ECHO OP CODE
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        L,A            LOAD ECHO CODE
         LD        H,00       CATEGORY 3 SET TO 0 FOR 
         CALL      R.XMIT        TEST IN TX.STOR FOR XMIT 
         RET                      EXIT
         EJECT     PROCESS LDA COMMAND
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        LOAD MEMORY ADDRESS, (LDA) 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
LDA      EQU       *
         CALL      GET3       GET NEXT 3 BYTES
         CALL      CHKRG      CHECK ADDRESS RANGE 
         LD        (MEMREG),HL
         RET
* 
* CHECK ADDRESS IN HL BETWEEN BOUNDS
* ADDRESS MUST BE BETWEEN BEGVAR1..ENDVAR1 OR ENDRES..7FFFH.
* ROUTINE RETURNS TO CALLER WITH HL UNCHANGED IF IN BOUNDS. 
* ROUTINE EXITS THE CALLER IF HL WAS OUT OF BOUNDS. 
CHKRG    EQU       *
         EX        DE,HL      ADDRESS TO DE 
         LD        HL,-ENDRES 
         ADD       HL,DE
         JR        NC,CHKRG0  JUMP IF &lt;END OF RESIDENT
 
         EX        DE,HL      ADDRESS BACK TO HL
         BIT       7,H
         RET       Z          EXIT IF OK (&lt;8000H) 
         EX        DE,HL      ADDRESS BACK TO DE
 
CHKRG0   EQU       *          ADDRESS IS <END OF RESIDENT 
         LD        HL,-BEGVAR1    OR >7FFFH 
         ADD       HL,DE
         JR        NC,CHKRG1  JUMP IF &lt;BEGVAR1 (ERROR)
 
         LD        HL,-ENDVAR1
         ADD       HL,DE
         EX        DE,HL      ADDRESS BACK TO HL
         RET       NC         EXIT IF &lt;ENDVAR1 (OK) 
 
CHKRG1   EQU       *          OUT OF BOUNDS 
         POP       HL 
         RET
         EJECT     SSF AND EXT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        SELECT SPECIAL FUNCTION
* 
*        THIS COMMAND IS USED TO COMMUNICATE WITH VARIOUS DEVI
*        CONNECTED TO THE EXTERNAL CHANNELS, AND SET THE TERMI
*        INTERNAL INTERRUPT MASK. 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
* 
*        ON-LINE ENTRY POINT
* 
SSF      EQU       *
         CALL      GET3       GET NEXT 3 BYTES
         RES       7,H        CLEAR UPPER BIT 
* 
*        USER ENTRY POINT 
* 
SSF0     EQU       *
         LD        A,H
         RRCA 
         RRCA 
         AND       1FH            MASK DEVICE ADDRESS BITS
         JR        NZ,SSF1        NOT SLIDE PROJECTOR 
* 
*        OUTPUT TO SLIDE PROJECTOR
* 
         LD        C,20H          LOAD SLIDE PROJECTOR ADDRESS
         OUT       (C),L          OUTPUT LOWER EIGHT BITS 
         LD        A,03 
         AND       H              MASK UPPER TWO BITS 
         OUT       (C),A          OUTPUT UPPER TWO BITS 
         RET
* 
SSF1     EQU       *
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         CP        01             TEST FOR INTERRUPT MASK 
         JR        NZ,SSF2        NOT INTERRUPT MASK
         LD        A,L            LOAD MASK 
         JP        ENAB             AND SET INTERRUPT NASK
* 
SSF2     EQU       *
         BIT       1,H            TEST FOR INPUT OR OUTPUT
         JR        NZ,SSF3        GO TO INPUT IF NOT ZERO 
* 
*        OUTPUT TO EXTERNAL DEVICE
* 
         LD        (EXT.OUT),A    STORE DEVICE ADDRESS
         LD        C,A
         BIT       0,H            TEST FOR DATA IN LOWER BITS 
         RET       NZ             EXIT IF NONE
* 
         LD        E,L
         LD        HL,EXTD        LOAD DATA STORE ADDRESS 
         LD        (HL),E           AND STORE DATA BYTE 
         CP        03         TEST FOR SERIAL/PARALLEL
         RET       Z          CANNOT OUTPUT TO SER CTRL PORT
         JP        C,SCOUT    JUMP IF SER DATA PORT 
         SET       5,C        SET EXTERNAL CHANNEL BIT
         OUTI                     OUTPUT DATA FROM MEMORY 
         RET
* 
* 
*        INPUT FROM EXTERNAL DEVICE 
* 
SSF3     EQU       *
         LD        (EXT.IN),A     STORE DEVICE ADDRESS
         LD        C,A
         BIT       0,H            TEST FOR DATA IN LOWER BITS 
         RET       NZ             EXIT IF NONE
         AND       1CH            TEST FOR SERIAL OR PARALLEL 
         JR        NZ,SSF4    JUMP IF PARALLEL CHANNEL
 
* SERIAL CHANNEL INPUT
         SET       4,C        SELECT SERIAL CHANNEL 
         BIT       0,C
         JR        Z,SSF4A    JUMP IF DATA INPUT
 
         LD        L,00H      STATUS INPUT....
         LD        A,11H      RESET EXTERNAL STATUS 
         OUT       (C),A
         IN        A,(C)      GET STATUS REG 1(ERROR STATUS)
         AND       70H
         JR        Z,SSF3A
         SET       4,L        SET RECEIVE DATA ERROR STATUS 
         LD        A,30H      RESET ERROR LATCHES 
         OUT       (C),A
SSF3A    EQU       *
         IN        A,(C)      GET STATUS REG 0
         AND       0ADH       CLEAR UNUSED BITS 
         OR        L          INSERT RECEIVE ERROR STATUS 
         LD        L,A
         IN        A,(COMMSW) GET DSR STATUS
         BIT       7,A
         JR        Z,SSF4B
         SET       1,L        SET DSR STATUS
         JR        SSF4B
 
* PARALLEL CHANNEL INPUT
SSF4     EQU       *
         SET       5,C        SELECT PARALLEL CHANNEL 
SSF4A    EQU       *
         IN        L,(C)          INPUT FROM DEVICE 
SSF4B    EQU       *
         LD        H,82H          LOAD OP CODE AND CATAGORY 
         LD        A,(M.KSW)      LOAD USER/PLATO FLAG
         PUSH      HL 
         CP        02         FOR M.KSW=0 OR M.KSW=1
         CALL      C,R.XMIT      STORE FOR TRANSMIT TO PLATO
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         POP       HL         FOR M.KSW=2 OR M.KSW=3
*                                RETURN DATA IN L TO USER 
         RET
         EJECT     EXT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        OUTPUT DATA TO EXTERNAL DEVICE 
* 
*        THIS COMMAND TRANSFERS TWO BYTES OF DATA TO THE DEVIC
*        CONNECTED TO THE EXTERNAL CHANNEL, AND ADDRESSED BY T
*        LAST SSF COMMAND RECEIVED BY THE TERMINAL. 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
* 
*        ON-LINE ENTRY POINT
* 
EXT      EQU       *
         CALL      GET3       GET NEXT 3 BYTES
         EX        DE,HL      SAVE DATA IN TEMP AREA
         LD        HL,EXTD+1
         LD        (HL),E 
         DEC       HL 
         LD        (HL),D     HL NOW POINTS TO TEMP AREA
         LD        DE,02          LOAD DATA BYTE COUNT
* 
*        USER ENTRY POINT 
* ON ENTRY, HL=FWA AND DE=LENGTH IN BYTES 
EXTX     EQU       *
         LD        A,(EXT.OUT)    LOAD EXTERNAL DEVICE ADDRESS
         LD        C,A
         AND       1CH            TEST FOR SERIAL OR PARALLEL 
         JR        NZ,EXT3    JUMP IF PARALLEL CHANNEL
 
* 
* SERIAL CHANNEL OUTPUT 
* 
         BIT       0,C
         JR        Z,EXT2     JUMP IF DATA OUTPUT 
 
         SET       4,C        SELECT SERIAL CHANNEL 
         SRL       D          CONTROL OUTPUT
         RR        E          DIVIDE BYTE COUNT BY 2
 
EXT0     EQU       *
         LD        A,(HL)     CHECK WHICH SIO REGISTER IS 
         AND       07H          BEING WRITTEN INTO
         DEC       A
         JR        NZ,EXT0A 
 
         INC       HL         REG 1 (CANNOT WRITE TO REG 1) 
         INC       HL 
         JR        EXT1 
 
EXT0A    EQU       *
         DEC       A
         JR        NZ,EXT0B 
 
         INC       HL         REG 2 SETS CLOCK RATE 
         LD        B,(HL)     GET RATE INFORMATION
         RES       0,B        INSERT LONG LINE/RS232 BIT
         LD        A,(RUNINFO)  FROM RUNINFO
         AND       01H
         OR        B
         OUT       (SERRATE),A
         INC       HL 
         JR        EXT1 
 
EXT0B    EQU       *
         OUTI                 OTHER REGISTERS ARE WRITTEN 
         OUTI                   INTO IN BYTE PAIRS
 
EXT1     EQU       *
         DEC       DE 
         LD        A,E
         OR        D
         JR        NZ,EXT0    LOOP UNTIL OUTPUT IS DONE 
         RET
 
EXT2     EQU       *
         CALL      SCOUT      DATA OUTPUT 
         DEC       DE 
         LD        A,E
         OR        D
         JR        NZ,EXT2
         RET
 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
* OUTPUT DATA FROM (HL) TO SERIAL I/O ADDRESS (C).
* OUTPUT IS ABORTED IF CHARACTER REQUEST TIMEOUT OCCURS.
SCOUT    EQU       *
         SET       4,C        SELECT SERIAL CHANNEL 
         LD        A,(M.CLOCK)  INITIALIZE TIMER
         ADD       A,8
         LD        B,A
SCOUT1   EQU       *
         IN        A,(SERSTAT)  CHECK SERIAL CHANNEL STATUS 
         BIT       2,A
         JR        NZ,SCOUT2  JUMP IF CHAR REQUEST
         LD        A,(M.CLOCK)
         CP        B
         JR        NZ,SCOUT1  LOOP IF NO TIMEOUT
         RET                  ABORT OUTPUT
 
SCOUT2   EQU       *
         OUTI                 OUTPUT DATA 
         RET
* 
*        PARALLEL CHANNELS
* 
EXT3     EQU       *
         SET       5,C        ADD EXT CHANNEL BIT 
* 
EXT4     EQU       *
         OUTI                     OUTPUT DATA FROM MEMORY 
* 
         DEC       DE             DECREMENT BYTE COUNT
         LD        A,D
         OR        E              TEST FOR LAST BYTE
         JR        NZ,EXT4        OUT PUT NEXT BYTE 
         RET
         SPACE     4
* 
*        COLOR COMMAND
* 
COLOR    EQU       *
         LD        HL,NBYTES
         INC       (HL) 
         LD        A,02 
         CP        (HL) 
         RET       NZ 
         XOR       A
         LD        (CMODE),A
         RET
         EJECT     MODE 0, POINT PLOT 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        POINT PLOT MODE
* 
*        EACH MODE 0 DATA WORD SPECIFIES THE COORDINATES ON TH
*        DISPAY TO BE WRITTEN OR ERASED. BIT 2 OF THE LAST LDM
*        COMMAND RECEIVED WILL DETERMINE WRITE OR ERASE.
* 
*        MODE 0 DATA WORD 
*                  BITS 1-9       Y COORDINATE
*                  BITS 10-18     X COORDINATE
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
         SPACE     1
APOINT   EQU       *
         CALL      GETXY      GET COORDINATES 
* 
*        WRITE/ERASE SINGLE DOT 
* 
*        USER ENTRY POINT 
         SPACE     1
POINT    EQU       *
         PUSH      DE        SAVE Y COORDINATE
         CALL      R.OUTX         LOAD X COORDINATE 
         POP       HL             RETREIVE Y COORDINATE 
         CALL      R.OUTY         LOAD Y COORDINATE 
         SPACE     1
*        USER ENTRY POINT 
         SPACE     1
WE       EQU       *
         CALL      MASKS          GENERATE WRITE/ERASE MASKS
* 
         EX        DE,HL
         LD        HL,(DMAA)      LOAD DMA ADDRESS
         LD        A,(M.MODE)     LOAD WRITE/ERASE FLAG 
         BIT       0,A            TEST FOR WRITE OR ERASE 
         JR        Z,MODE01       GO TO ERASE 
* 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        A,E            LOAD WRITE MASK 
         OR        (HL)           INCLUDE POINT IN DMA DATA 
         LD        (HL),A           AND STORE IN DMA
         RET
* 
MODE01   EQU       *
         LD        A,D            LOAD ERASE MASK 
         AND       (HL)           ERASE POINT 
         LD        (HL),A         STORE RESULT IN DMA 
         RET
         EJECT     MODE 1, VECTOR GENERATOR 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        VECTOR MODE
* 
*        EACH DATA WORD RECEIVED SPECIFIES THE END COORDINATES
*        THE LINE TO BE DRAWN. THIS LINE IS DRWWN BETWEEN THE 
*        CURRENT COORDINATES AND THE END COORDINATES SPECIFIED
*        THE MODE 1 DATA WORD. THE END COORDINATES IS ALSO THE
*        OF THE NEXT LINE TO BE DRAWN.
* 
*        MODE 1 DATA WORD 
*                  BITS 1-9       Y COORDINATE
*                  BITS 10-18     X COORDINATE
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
GRAPH    EQU       *
         CALL      GETXY      GET COORDINATES 
         LD        A,(DARK) 
         AND       A          IF DARK VECTOR, 
         JR        Z,ALINE       BASE POSITION
         PUSH      DE         SAVE Y COORD
         CALL      R.OUTX     OUTPUT X
         POP       HL 
         CALL      R.OUTY     OUTPUT Y
         XOR       A          TURN OFF DARK VECTOR
         LD        (DARK),A 
         RET
* 
ALINE    EQU       *
         LD        A,(DASH)   LOAD FLAG FOR DASHED/SOLID
         RRA
         JP        C,G.LINE1  IF SET, USE DASHED VECTOR 
*                             OTHERWISE R.LINE
* 
LINE     EQU       *
* 
         LD        (XEND),HL      STORE X END COORDINATE
         EX        DE,HL
         LD        (YEND),HL      STORE Y END COORDINATE
* 
         LD        C,00           CLEAR C FOR VECTOR FLAG 
         LD        HL,(XREG)      LOAD CURRENT X COORDINATE 
         CALL      CALDELX        CALCULATE DELTA X 
         LD        HL,(YREG)      LOAD CURRENT Y COORDINATE 
         CALL      CALDELY        CALCULATE DELTA Y 
* 
         LD        A,08H      TEST FOR NEGATIVE X 
         AND       C
         LD        A,C
         LD        (VECFLG),A     STORE VECTOR FLAG 
         JR        Z,MODE11       JUMP IF Y POSITIVE
         XOR       10H        TOGGLE Y DIRECTION
         LD        (VECFLG),A       AND STORE 
         LD        HL,(YEND)      RESET VECTOR
         CALL      R.OUTY           LOAD COORDINATE.
         LD        HL,(XEND)
         CALL      R.OUTX           LOAD COORDINATE.
* 
MODE11   EQU       *
         LD        HL,(YDELTA)
         EX        DE,HL
         LD        HL,(XDELTA)    LOAD DELTA X
         SBC       HL,DE
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         JR        NC,MODE12      JUMP IF X GREATER 
* 
*        DELTA Y GREATER
* 
         LD        HL,(XDELTA)    LOAD DELTA X
         CALL      DIVIDE         CALCULATE SLOPE 
         LD        BC,(YDELTA) LOAD DELTA FOR LOOP COUNT
         CALL      VECINIT    INIT REGS FOR VECTOR ROUTINE
         JR        YVEC 
* 
*        DELTA Y IS EQUAL TO OR LESS THAN DELTA X 
* 
MODE12   EQU       *
         LD        HL,(XDELTA)    LOAD DELTA X
         EX        DE,HL
         CALL      DIVIDE         CALCULATE SLOPE 
         LD        BC,(XDELTA)    LOAD DELTA FOR LOOP COUNT 
         CALL      VECINIT    INIT REGS FOR VECTOR ROUTINE
         JR        XVEC 
* 
* INITIALIZATION ROUTINE FOR VECTOR GENERATORS. 
* 
VECINIT  EQU       *
         LD        A,C        TOGGLE BIT 7 OF C FOR 
         XOR       80H            USE BY VECTOR GENERATOR 
         LD        C,A            JP,PE INSTRUCTION 
         EXX
         CALL      MASKS              GENERATE MASKS
         LD        C,L
         LD        B,00       SET WRITE MASK
         LD        DE,0FFFFH  LOAD FOR POSITIVE 'Y
         LD        HL,(DMAA)      LOAD STARTING ADDRESS 
         LD        A,(VECFLG)     LOAD VECTOR PARAMETERS
         BIT       4,A        TEST FOR POS 'Y DELTA 
         JR        Z,VECINIT1     JUMP IF X POSITIVE
* 
         INC       DE         SET DE FOR
         INC       DE         NEGATIVE 'Y 
* 
VECINIT1 EQU       *
         LD        A,(M.MODE)     TEST MODE BITS
         RRA                        FOR WRITE OR ERASE
         RET       C          GO TO WRITE VECTOR
         DEC       B          SET ERASE MASK
         RET                  GO TO ERASE VECTOR
         EJECT
* VECTOR GENERATOR.  Y IS LONG AXIS, X IS SHORT AXIS. 
* WRITE/ERASE VECTOR. 
* 
* ON ENTRY, 
*   B=WRITE/ERASE MASK (00=WRITE, FF=ERASE) 
*   C=BIT MASK (BIT TO BE CHANGED=1, OTHER BITS=0)
*  DE=-1 IF WRITING UP TO RIGHT, +1 IF WRITING DOWN TO RIGHT
*  HL=CURRENT DISPLAY MEMORY ADDRESS
*  BC*=DELTA Y (BIT 7 OF C IS TOGGLED FOR USE WITH JP,PE) 
*  DE*=SLOPE
*  HL*=ACCUMULATOR (INITIALLY 8000H)
* 
*  ENTRY POINT IS YVEC. 
* 
* THIS CODE IS TIME OPTIMIZED.  DO NOT CHANGE WITHOUT 
* CAREFUL THOUGHT.
* 
* TIMING FOR THIS ROUTINE.
* 
* T STATES = 110*DELTA Y + 13*DELTA X 
*        + 26*NO. OF HORIZONTAL BYTE BOUNDARIES CROSSED 
*        + 16 (IF DELTA Y >=256) + 85 
* 
* TIME FOR DELTA Y=511, DELTA X=000 IS 14.078 MILLISECONDS. 
* TIME FOR DELTA Y=511, DELTA X=510 IS 16.145 MILLISECONDS. 
* 
YVEC1    EQU       *
         ADD       HL,DE      ADD SLOPE TO ACCUMULATOR
         EXX
         JR        NC,YVEC2 
 
         RLC       C          MOVE ONE DOT RIGHT
         JR        C,YVEC3
 
YVEC2    EQU       *
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         ADD       HL,DE      MOVE ONE DOT UP OR DOWN 
         SET       7,H
 
* ENTRY POINT 
YVEC     EQU       *
         LD        A,(HL)     MODIFY CURRENT DOT
         XOR       B
         OR        C
         XOR       B
         LD        (HL),A 
 
         EXX                  DECREMENT AND TEST COUNT
         DEC       C
         JP        PO,YVEC1   (LOOP IF NO OVERFLOW) 
 
         DEC       B
         JP        P,YVEC1    LOOP IF NOT DONE YET
         JP        MODE19     EXIT
 
YVEC3    EQU       *
         INC       H          MOVE RIGHT ONE BYTE 
         INC       H
         JP        YVEC2
         EJECT
* VECTOR GENERATOR.  X IS LONG AXIS, Y IS SHORT AXIS. 
* WRITE/ERASE VECTOR. 
* 
* ON ENTRY, 
*   B=WRITE/ERASE MASK (00=WRITE, FF=ERASE) 
*   C=BIT MASK (BIT TO BE CHANGED=1, OTHER BITS=0)
*  DE=-1 IF WRITING UP TO RIGHT, +1 IF WRITING DOWN TO RIGHT
*  HL=CURRENT DISPLAY MEMORY ADDRESS
*  BC*=DELTA X (BIT 7 OF C IS TOGGLED FOR USE WITH JP,PE) 
*  DE*=SLOPE
*  HL*=ACCUMULATOR (INITIALLY 8000H)
* 
*  ENTRY POINT IS XVEC. 
* 
* THIS CODE IS TIME OPTIMIZED.  DO NOT CHANGE WITHOUT 
* CAREFUL THOUGHT.
* 
* TIMING FOR THIS ROUTINE.
* 
* T STATES = 106*DELTA X + 17*DELTA Y 
*        + 36*NO. OF HORIZONTAL BYTE BOUNDARIES CROSSED 
*        + 16 (IF DELTA X >=256) + 85 
* 
* TIME FOR DELTA X=511, DELTA Y=000 IS 14.134 MILLISECONDS. 
* TIME FOR DELTA X=511, DELTA Y=511 IS 16.306 MILLISECONDS. 
* 
XVEC1    EQU       *
         ADD       HL,DE      ADD SLOPE TO ACCUMULATOR
         EXX
         JR        NC,XVEC2 
 
         ADD       HL,DE      MOVE ONE DOT UP OR DOWN 
         SET       7,H
 
XVEC2    EQU       *
         RLC       C          MOVE ONE DOT RIGHT
         JR        C,XVEC3
 
* ENTRY POINT 
XVEC     EQU       *
         LD        A,(HL)     MODIFY CURRENT DOT
         XOR       B
         OR        C
         XOR       B
         LD        (HL),A 
 
         EXX                  DECREMENT AND TEST COUNT
         DEC       C
         JP        PO,XVEC1   (LOOP IF NO OVERFLOW) 
 
         DEC       B
         JP        P,XVEC1    LOOP IF NOT DONE YET
         JP        MODE19     EXIT
 
XVEC3    EQU       *
         INC       H          MOVE RIGHT ONE BYTE 
         INC       H
         SET       7,H
         JP        XVEC 
* 
* 
* 
MODE19   EQU       *
         LD        HL,(YEND)
         CALL      R.OUTY           LOAD COORDINATE.
         LD        HL,(XEND)
         JP        R.OUTX           LOAD COORDINATE.
         EJECT     MODE 2, DATA LOAD AND STORE
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
*        LOAD TERMINAL MEMORY 
* 
*        EACH DATA WORD RECEIVED CONTAINS 16 BITS OF DATA TO B
*        STORED IN THE TERMINAL MEMORY. THIS DATA IS STORED IN
*        SUCCESSIVE LOCATIONS STARTING WITH THE CURRENT CONTEN
*        OF THE MEMORY ADDRESS REGISTER. AFTER EACH EIGHT BITS
*        IS STORED, THE MEMORY ADDRESS REGISTER IS INCREMENTED
*        THE MEMORY ADDRESS REGISTER IS INITIALIZED BY THE
*        LAST LDA COMMAND RECEIVED. 
* 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     2
MEMORY   EQU       *
         CALL      GET3       GET NEXT 3 BYTES
         LD        B,H        SAVE DATA IN BC 
         LD        C,L
         LD        HL,(MEMREG) GET MEMORY ADDRESS 
         CALL      CHKRG      CHECK AGAINST BOUNDS
         LD        (HL),C     STORE DATA
         INC       HL 
         LD        (HL),B 
         INC       HL 
         LD        (MEMREG),HL SAVE UPDATED ADDRESS 
         LD        A,(CONFLG)    TEST FOR CONVERTING
         OR        A             CHAR. DATA 
         RET       Z          DO NOT CONVERT
 
         LD        A,(NDATAB) 
         INC       A
         LD        (NDATAB),A  INCREMENT COUNT ON DATA BYTES
         CP        08         IF 16 BYTES, THEN CONVERT DATA
         RET       NZ 
         LD        DE,0010H 
         XOR       A          CLEAR CARRY 
         SBC       HL,DE
         EX        DE,HL      DE _ FWA CHAR. DATA 
         LD        HL,0001    HL _ CHAR. COUNT OF 1 
         CALL      CONVERT
         XOR       A
         LD        (NDATAB),A    CLEAR NUMBER DATA BYTES FG.
         RET
         EJECT     MODE 3, CHARACTER GENERATOR
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
* 
*        ALPHA MODE 
* 
*        MODE 3 DATA WORDS ARE CHARACTERS TO BE DISPLAYED.
*        ON ENTRY, THE CHAR IS IN THE C-REG.
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     2
CHARACT  EQU       *
         LD        A,(MODE)   CHECK MODE
         RLCA 
         JP        NC,ALPHMODE  GO TO ASCII CHAR GEN
 
         LD        HL,M.CCR   IS REVERSE SET
         BIT       6,(HL) 
         JR        Z,CHARS0   NO, JUMP
 
         PUSH      BC         YES, DO TAB FIRST 
         EX        DE,HL      PUT M.CCR IN DE 
         CALL      TAB
         POP       BC 
 
CHARS0   LD        DE,(MEMSEL)   DISPLAY THE CHARACTER
         LD        A,C
         SUB       20H
         LD        L,A
         JP        CHARGEN
 
**********
* USER ENTRY POINT
**********
CHARS    EQU       *
         LD        A,(HL)     GET DATA
         RES       7,A        MASK TO 7 BITS
         INC       HL 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        (CHFWA),HL SAVE CHAR ADDRESS 
         LD        HL,M.CCR 
         CP        3FH        IS CHAR AN UNCOVER CODE 
         JR        NZ,CHARS1  NO, JUMP
 
         SET       7,(HL)     SET UNCOVER FLAG
         JR        CHARS6 
 
CHARS1   EQU       *
         BIT       7,(HL)     IS UNCOVER FLAG SET 
         JR        NZ,CHARS10 YES, JUMP TO HANDLE CTL CODES 
 
         BIT       6,(HL)     IS REVERSE SET
         JR        Z,CHARS2   NO, JUMP
 
         PUSH      AF         YES, DO TAB BEFORE PLOTTING 
         PUSH      HL 
         EX        DE,HL      PUT M.CCR INTO DE 
         CALL      TAB
         POP       HL 
         POP       AF 
 
CHARS2   EQU       *          NOW PLOT THE CHAR 
         LD        C,A        SAVE CHAR IN C
         LD        A,(HL)     GET SELECTED CHAR MEM 
         AND       0EH
         JR        Z,CHARS4   JUMP IF M0 SELECTED 
         SUB       2
         JR        Z,CHARS3   JUMP IF M1 SELECTED 
         LD        DE,(MEMSEL)  M2..M7, SO USE SELECTED MEM 
         LD        L,C          AND UNTRANSLATED CHAR 
         JR        CHARS5 
 
CHARS3   EQU       *          M1 SELECTED, SO 
         SET       6,C          BIAS CHAR 
 
CHARS4   EQU       *          M0 OR M1 SELECTED 
         LD        B,0        TRANSLATE CHAR TO ASCII 
         LD        HL,PCHARS
         ADD       HL,BC
         LD        L,(HL)     GET BIASED ASCII CHAR IN L
         LD        DE,M0CODE00  M0 IF L7=0
         BIT       7,L
         JR        Z,CHARS5 
         RES       7,L        CLEAR FLAG BIT
         LD        DE,M1CODE00  M1 IF L7=1
 
CHARS5   EQU       *
         CALL      CHARGEN    DISPLAY THE CHAR
 
CHARS6   EQU       *
         LD        HL,(CHFWA) GET SAVED CHAR ADDRESS
         JR        CHARS      LOOP
 
CHARS10  EQU       *          UNCOVER FLAG IS SET 
         DEC       A          EXIT IF CHAR=01 
         RET       Z
 
         RES       7,(HL)     CLEAR UNCOVER FLAG
         INC       A          EXIT IF CHAR=00 
         RET       Z
 
         CP        08H        EXECUTE CONTROL CODES 
         JR        C,CHARS6   IGNORE 00-07
 
         CP        0EH
         JR        NC,CHARS11 
 
         LD        C,A        EXCUTE 08-0D
         CALL      EX.CTL 
         JR        CHARS6 
 
CHARS11  EQU       *
         CP        1EH
         JR        NC,CHARS6  IGNORE 1E-7F
 
         ADD       A,32H      EXECUTE 0E-1D 
         LD        C,A        (BIASED TO 40-4F) 
         CALL      EX.ESC 
         JR        CHARS6 
 
         EJECT
**********
* THE FOLLOWING TABLE IS USED TO TRANSLATE FROM 6-BIT 
* PLATO CHARACTER CODES TO ASCII CODES. 
* BIT 7 SET INDICATES THE CHARACTER IS PHYSICALLY FOUND IN
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
* M1, WHILE BIT 7 CLEAR INDICATES THE CHARACTER IS
* PHYSICALLY FOUND IN M0.  BITS 6-0 ARE THE ASCII CHARACTER 
* WITH 20H SUBTRACTED OFF FOR USE BY THE CHARACTER GENERATOR
**********
PCHARS   EQU       *
         HEX       1A,41,42,43  0X  (M0)
         HEX       44,45,46,47
         HEX       48,49,4A,4B
         HEX       4C,4D,4E,4F
         HEX       50,51,52,53  1X
         HEX       54,55,56,57
         HEX       58,59,5A,10
         HEX       11,12,13,14
         HEX       15,16,17,18  2X
         HEX       19,0B,0D,0A
         HEX       0F,08,09,04
         HEX       1D,00,0C,0E
         HEX       8F,3B,3D,05  3X
         HEX       8A,84,07,02
         HEX       01,1B,1C,1E
         HEX       3F,1F,9F,00
 
         HEX       03,21,22,23  4X  (M1)
         HEX       24,25,26,27
         HEX       28,29,2A,2B
         HEX       2C,2D,2E,2F
         HEX       30,31,32,33  5X
         HEX       34,35,36,37
         HEX       38,39,3A,83
         HEX       80,3E,A6,40
         HEX       86,87,88,89  6X
         HEX       5E,8B,8C,8D
         HEX       8E,5B,5D,06
         HEX       85,00,AA,9D
         HEX       82,90,91,92  7X
         HEX       93,94,95,96
         HEX       97,98,99,9A
         HEX       9B,20,3C,00
         EJECT
* 
* 
*        BACKSPACE
* 
BKSP     EQU       *
         LD        A,(DE)         LOAD PLOTTING FLAG
         XOR       40H        TOGGLE FORW/REV BIT 
         JR        TAB0 
* 
*        HORIZONTAL TAB 
* 
TAB      EQU       *
         LD        A,(DE)         LOAD PLOTTING FLAG
* 
TAB0     EQU       *
         LD        DE,(SIZE)      LOAD CHARACTER SIZE 
         BIT       0,A            TEST FOR HORIZONTAL/VERTICAL
         JR        NZ,TAB2        GO TO VERT ROUTINE
         BIT       6,A            TEST FOR FORWARD/REVERSE
         LD        HL,(XREG)      LOAD CURRENT X COORDINATE 
         JR        NZ,TAB1        GO TO REVERSE ROUTINE 
* 
         ADD       HL,DE          ADD CHARACTER SIZE
         JP        R.OUTX           LOAD COORDINATE.
* 
TAB1     EQU       *
         AND       A              CLEAR CARRY BIT 
         SBC       HL,DE          SUBTRACT CHARACTER SIZE 
         JP        R.OUTX           LOAD COORDINATE.
* 
TAB2     EQU       *
         BIT       6,A            TEST FOR FORWARD/REVERSE
         LD        HL,(YREG)      LOAD CURRENT Y COORDINATE 
         JR        NZ,TAB3        GO TO REVERSE ROUTINE 
* 
         ADD       HL,DE          ADD CHARACTER SIZE
         JP        R.OUTY           LOAD COORDINATE.
* 
TAB3     EQU       *
         AND       A              CLEAR CARRY BIT 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         SBC       HL,DE          SUBTRACT CHARACTER SIZE 
         JP        R.OUTY           LOAD COORDINATE.
* 
*        LINE FEED
* 
LF       EQU       *
         LD        HL,(SIZE)      LOAD CHARACTER SIZE 
         ADD       HL,HL            AND ADJUST FOR HEIGHT 
         EX        DE,HL
         BIT       0,(HL)         TEST FOR HOR/VERT 
         JR        NZ,LF1         GO TO VERTICAL ROUTINE
* 
         LD        HL,(YREG)      LOAD CURRENT Y COORDINATE 
         AND       A              CLEAR CARRY BIT 
         SBC       HL,DE          SUBTRACT CHARACTER SIZE 
         JP        R.OUTY           LOAD COORDINATE.
* 
LF1      EQU       *
         LD        HL,(XREG)      LOAD CURRENT X COORDINATE 
         ADD       HL,DE          ADD CHARACTER SIZE
         JP        R.OUTX           LOAD COORDINATE.
* 
*        VERTICAL TAB 
* 
VT       EQU       *
         LD        HL,(SIZE)      LOAD CHARACTER SIZE 
         ADD       HL,HL            AND ADJUST FOR HEIGHT 
         EX        DE,HL
         BIT       0,(HL)         TEST FOR HOR/VERT 
         JR        NZ,VT1         GO TO VERTICAL ROUTINE
* 
         LD        HL,(YREG)      LOAD CURRENT Y COORDINATE 
         ADD       HL,DE          ADD CHARACTER SIZE
         JP        R.OUTY           LOAD COORDINATE.
* 
VT1      EQU       *
         LD        HL,(XREG)      LOAD CURRENT X COORDINATE 
         AND       A              CLEAR CARRY BIT 
         SBC       HL,DE          SUBTRACT CHARACTER SIZE 
         JP        R.OUTX           LOAD COORDINATE.
* 
*        FORM FEED
* 
FF       EQU       *
         LD        HL,512 
         LD        A,(M.CCR)      LOAD PLOTTING PARAMETERS
         BIT       6,A            TEST FOR FORWARD OR REVERSE 
         JR        Z,FF1          JUMP IF FORWARD 
* 
         LD        DE,(SIZE)      LOAD CHARACTER SIZE 
         AND       A              CLEAR CARRY BIT 
         SBC       HL,DE            AND SUBTRACT FROM FULL SCE
* 
FF1      EQU       *
         BIT       0,A            TEST FOR HORIZONTAL OR VERTI
         JR        NZ,FF2         JUMP IF VERTICAL
* 
         CALL      R.OUTX           LOAD COORDINATE.
* 
         LD        HL,(SIZE)      LOAD CHARACTER SIZE 
         ADD       HL,HL            AND DOUBLE IT 
         LD        DE,512         LOAD FULL SCREEN SIZE 
         EX        DE,HL
         AND       A              CLEAR CARRY BIT 
         SBC       HL,DE          SUBTRACT SIZE FROM FULL SCRE
         JP        R.OUTY           LOAD COORDINATE.
* 
FF2      EQU       *
         CALL      R.OUTY           LOAD COORDINATE.
* 
         LD        HL,(SIZE)      LOAD CHARACTER SIZE 
         ADD       HL,HL            AND DOUBLE IT 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         DEC       HL                 SUBTRACT ONE
         JP        R.OUTX           LOAD COORDINATE.
* 
*        CARRIAGE RETURN
* 
CR       EQU       *
         LD        HL,(SIZE)      LOAD CHARACTER SIZE 
         ADD       HL,HL            AND ADJUST FOR HEIGHT 
         EX        DE,HL
         BIT       0,(HL)         TEST FOR HOR/VERT 
         JR        NZ,CR1         GO TO VERTICAL ROUTINE
* 
         LD        HL,(YREG)      LOAD CURRENT Y COORDINATE 
         AND       A              CLEAR CARRY BIT 
         SBC       HL,DE          SUBTRACT CHARACTER SIZE 
         CALL      R.OUTY         LOAD Y COORDINATE 
         LD        HL,(M.MARGIN)  LOAD MARGIN 
         JP        R.OUTX           LOAD COORDINATE.
* 
CR1      EQU       *
         LD        HL,(XREG)      LOAD CURRENT X COORDINATE 
         ADD       HL,DE          ADD CHARACTER SIZE
         CALL      R.OUTX         LOAD X COORDINATE 
         LD        HL,(M.MARGIN)  LOAD MARGIN 
         JP        R.OUTY           LOAD COORDINATE.
* 
SUB      EQU       *
         LD        HL,-0005       LOAD DISPLACEMENT 
         JR        SUB0 
* 
SUPER    EQU       *
         LD        HL,0005        LOAD DISPLACEMENT 
SUB0     EQU       *
         LD        A,(DE)         LOAD PLOTTING FLAFG 
         BIT       0,A            TEST HORIZONTAL OR VERTICAL 
         JR        NZ,SUP1        GO TO VERTICAL PLOT 
* 
         BIT       5,A
         JR        Z,SUP0         JUMP IF SIZE ZERO 
         ADD       HL,HL            ELSE DOUBLE DISPLACEMENT
SUP0     EQU       *
         EX        DE,HL
         LD        HL,(YREG)      LOAD Y COORDINATE 
         ADD       HL,DE          ADJUST COORDINATE 
         JP        R.OUTY           LOAD COORDINATE.
* 
SUP1     EQU       *
         BIT       5,A
         JR        Z,SUP2         JUMP IF SIZE ZERO 
         ADD       HL,HL            ELSE DOUBLE DISPLACEMENT
SUP2     EQU       *
         EX        DE,HL
         LD        HL,(XREG)      LOAD X COORDINATE 
         AND       A              CLEAR CARRY BIT 
         SBC       HL,DE          ADJUST COORDINATE 
         JP        R.OUTX           LOAD COORDINATE.
* 
SELECTMM EQU       *
         LD        A,C        GET CHAR
         SUB       42H        REMOVE BIAS 
         RLCA 
         CALL      LDMEMSEL   SELECT M0..M7 
         LD        HL,M.CCR   UPDATE MEM SEL BITS IN (M.CCR)
         LD        A,0F1H 
         AND       (HL) 
         OR        C
         LD        (HL),A 
         RET
 
* CALLABLE ROUTINE TO SELECT M0..M7 AS SPECIFIED IN A-REG.
* 
* ON ENTRY.. A-REG = 2 * MEM NO.
* 
* ON EXIT... (MEMSEL) = FWA OF MEM NO.
*            C-REG = 2 * MEM NO.
* 
LDMEMSEL EQU       *
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        C,A        SAVE 2*MEM IN C 
         LD        DE,M0CODE00
         OR        A
         JR        Z,LDMEM1   JUMP IF M0 SELECTED 
         LD        DE,M1CODE00
         DEC       A
         DEC       A
         JR        Z,LDMEM1   JUMP IF M1 SELECTED 
         LD        B,0        SELECT M2..M7 
         LD        HL,MEM2-4
         ADD       HL,BC
         LD        E,(HL) 
         INC       HL 
         LD        D,(HL) 
LDMEM1   LD        (MEMSEL),DE
         RET
* 
HOR      EQU       *
         EX        DE,HL
         RES       0,(HL)           AND SET HORIZONTAL PLOT 
         JP        CG.SEL         SELECT CHARACTER GENERATOR
* 
VERT     EQU       *
         EX        DE,HL
         SET       0,(HL)           AND SET VERTICAL PLOT 
         JP        CG.SEL         SELECT CHARACTER GENERATOR
* 
FWD      EQU       *
         EX        DE,HL
         RES       6,(HL)           AND SET FORWARD PLOT
         RET
* 
REV      EQU       *
         EX        DE,HL
         SET       6,(HL)           AND SET REVERSE PLOT
         RET
* 
SIZE0    EQU       *
         LD        HL,08          LOAD SIZE ONE CHARACTER 
         LD        (SIZE),HL
         EX        DE,HL
         RES       5,(HL)         SET SIZE 0 FLAG 
         RET
* 
SIZE2    EQU       *
         LD        HL,10H         LOAD SIZE TWO CHARACTER 
         LD        (SIZE),HL
         EX        DE,HL
         SET       5,(HL)         SET SIZE 2 FLAG 
         RET
         EJECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *
* 
*        CHARACTER GENERATOR
*        CALCULATES CHARACTER DATA ADDRESS AND JUMPS TO CHARAC
*        GENERATOR FOR PLOTTING DATA. 
* 
*        ON ENTRY,  L CONTAINS BIASED CHAR TO PLOT
*                  DE CONTAINS FWA OF CHAR MEM TO BE USED 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
CHARGEN  EQU       *
* 
         LD        H,00           ADJUST CHARACTER CODE 
         ADD       HL,HL              CHARACTER DATA TABLE
         ADD       HL,HL
         ADD       HL,HL
         ADD       HL,HL
         LD        BC,000FH 
         ADD       HL,BC
         ADD       HL,DE          CHARACTER DAT ADDRESS 
         LD        A,(M.CCR)      LOAD PLOTTING PARAMETERS
         BIT       5,A            TEST FOR SIZE ZERO OR SIZE T
         JP        NZ,SIZE.2
* 
         EX        DE,HL
         LD        HL,(CG.ADR)    LOAD CHARACTER GENERATOR ADD
         JP        (HL) 
         EJECT     BLOCK WRITE/ERASE
         EJECT     SIZE 2 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        SIZE 2 CHARACTER GENERATOR 
*        CHARACTER DATA IS EXPANDED TO DOUBLE THE WIDTH AND HE
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
*        OF THE CHARACTER AS IT IS DISPLAYED ON THE DISPLAY SC
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
SIZE.2   EQU       *
         PUSH      HL         PUT CHAR. DATA ADDR.
         POP       IX            INTO  IX REG.
         LD        DE,SAVE3F  LOAD TEMP. STORE ADDRESSES
         LD        HL,SAVE1F
         EXX
         LD        BC,0010H   BYTE COUNT
SIZE2.A  EQU       *
         EXX
         LD        B,02       PASS COUNT
         LD        C,(IX+0)   DATA BYTE 
SIZE2.B  EQU       *
         XOR       A          EXPLODE 4 BITS TO 16 BITS 
         SRL       C
         JR        NC,SIZE2.C 
         OR        03 
SIZE2.C  EQU       *
         SRL       C
         JR        NC,SIZE2.D 
         OR        0CH
SIZE2.D  EQU       *
         SRL       C
         JR        NC,SIZE2.E 
         OR        30H
SIZE2.E  EQU       *
         SRL       C
         JR        NC,SIZE2.F 
         OR        0C0H 
SIZE2.F  EQU       *
         LD        (DE),A     STORE EXPLODED DATA 
         DEC       DE 
         LD        (DE),A 
         DEC       DE 
         EX        DE,HL
         DJNZ      SIZE2.B    LOOP ON 2 PASSES
         DEC       IX         POINT TO NEXT CHAR. DATA BYTE 
         EXX
         DEC       BC         LOOP ON 16 COUNT
         LD        A,B
         OR        C
         JR        NZ,SIZE2.A 
         EXX
         LD        A,(M.CCR)
         BIT       0,A
         JR        NZ,SIZE2V  DO VERTICAL SIZE TWO
SIZE2H   EQU       *
         LD        HL,SAVE3F  LOAD 3RD QUAD.
         CALL      CHARGEN1      AND DISPLAY
         SPACE     2
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        HORIZONTAL PLOT
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
         BIT       6,A            TEST FOR REVERSE PLOT 
         JR        NZ,SIZE2R  DO REVERSE CHAR. PLOTTING 
         LD        HL,(XREG)      LOAD X COORDINATE 
         LD        DE,-8
         ADD       HL,DE          ADJUST FOR TOP HALF 
         CALL      R.OUTX           LOAD COORDINATE.
         LD        HL,(YREG)      LOAD Y COORDINATE 
         LD        DE,10H 
         ADD       HL,DE
         CALL      R.OUTY           LOAD COORDINATE.
* 
         LD        HL,SAVE2F  LOAD 2ND QUAD.
         CALL      CHARGEN1         AND DISPLAY 
         LD        HL,SAVE0F  LOAD 1ST QUAD.
         CALL      CHARGEN1         AND DISPLAY 
* 
         LD        HL,(XREG)      LOAD X COORDINATE 
         LD        DE,-8
         ADD       HL,DE          ADJUST COORDINATE FOR NEXT P
         CALL      R.OUTX           LOAD COORDINATE.
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        HL,(YREG)      LOAD Y COORDINATE 
         LD        DE,-10H
         ADD       HL,DE          ADJUST COORDINATE FOR NEXT P
         CALL      R.OUTY           LOAD COORDINATE.
* 
         LD        HL,SAVE1F  LOAD 4TH QUAD.
         JP        CHARGEN1       PLOT LAST PART OF CHARACTER 
         SPACE     2
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        REVERSE HORIZONTAL PLOT
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
SIZE2R   EQU       *
         LD        HL,(YREG)      LOAD Y COORDINATE 
         LD        DE,10H 
         ADD       HL,DE
         CALL      R.OUTY           LOAD COORDINATE.
* 
         LD        HL,SAVE2F  LOAD 2ND QUAD.
         CALL      CHARGEN1       PLOT NEXT PART OF CHARACTER 
         LD        HL,(XREG)      LOAD CURRENT X COORDINATE 
         LD        DE,08          LOAD ADJUST CONSTANT
         ADD       HL,DE
         CALL      R.OUTX           LOAD COORDINATE.
         LD        HL,SAVE0F  LOAD 1ST QUAD.
         CALL      CHARGEN1       PLOT NEXT PART OF CHARACTER 
         LD        HL,(YREG)      LOAD Y COORDINATE 
         LD        DE,-10H
* /---   BLOCK      NORTHS     00 000   73/00/00  00.00 
         ADD       HL,DE          ADJUST COORDINATE FOR NEXT P
         CALL      R.OUTY           LOAD COORDINATE.
* 
         LD        HL,SAVE1F  LOAD 4TH QUAD.
         CALL      CHARGEN1       PLOT LAST PART OF CHARACTER 
         LD        HL,(XREG)      LOAD CURRENT X COORDINATE 
         LD        DE,-08         LOAD ADJUST CONSTANT
         ADD       HL,DE
         JP        R.OUTX           LOAD COORDINATE.
         SPACE     2
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        VERTICAL PLOT
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
SIZE2V   EQU       *
         LD        HL,SAVE3F  PLOT 3RD QUAD 
         CALL      CHARGEN1 
         LD        A,(M.CCR)  TEST FOR REVERSE PLOTTING 
         BIT       6,A
         JR        NZ,SIZE2VR DO VERTICAL REVERSE PLOT
         LD        HL,(XREG)  POSITION FOR 2ND QUAD 
         LD        DE,-10H
         ADD       HL,DE
         CALL      R.OUTX 
         LD        HL,(YREG)
         LD        DE,-08H
         ADD       HL,DE
         CALL      R.OUTY 
         LD        HL,SAVE2F  PLOT 2ND QUAD 
         CALL      CHARGEN1 
         LD        HL,SAVE0F  PLOT 1ST QUAD 
         CALL      CHARGEN1 
         LD        HL,(XREG)  POSITION FOR 4TH QUAD 
         LD        DE,10H 
         ADD       HL,DE
         CALL      R.OUTX 
         LD        HL,(YREG)
         LD        DE,-08H
         ADD       HL,DE
         CALL      R.OUTY 
         LD        HL,SAVE1F  PLOT 4TH QUAD 
         JP        CHARGEN1 
         EJECT     SIZE 2 VERTICAL REVERSE
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        REVERSE VERTICAL PLOT
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
SIZE2VR  EQU       *
         LD        HL,(XREG)  POSITION FOR 2ND QUAD 
         LD        DE,-10H
         ADD       HL,DE
         CALL      R.OUTX 
         LD        HL,SAVE2F  PLOT 2ND QUAD 
         CALL      CHARGEN1 
         LD        HL,(YREG)  POSITION FOR 1ST QUAD 
         LD        DE,08H 
         ADD       HL,DE
         CALL      R.OUTY 
         LD        HL,SAVE0F  PLOT 1ST QUAD 
         CALL      CHARGEN1 
         LD        HL,(XREG)  POSITION FOR 4TH QUAD 
         LD        DE,10H 
         ADD       HL,DE
         CALL      R.OUTX 
         LD        HL,SAVE1F  PLOT 4TH QUAD 
         CALL      CHARGEN1 
         LD        HL,(YREG)  POSITION FOR NEXT CHAR
         LD        DE,-08H
         ADD       HL,DE
         CALL      R.OUTY 
         RET
CHARGEN1 EQU       *
         EX        DE,HL
         LD        HL,(CG.ADR)    LOAD CHARACTER GENERATOR ADD
         JP        (HL) 
         EJECT     FAST PLOT NORMAL(HORIZONTAL) 
**********
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
*        FAST HORIZONTAL PLOT NORMAL
**********
         SPACE     2
FHPLOT   EQU       *
         LDDR 
FH.ADV   EQU       *
         LD        HL,0010H   MOVE TO CHARACTER BOTTOM
         ADD       HL,DE
         LD        A,(M.CCR)
         BIT       6,A
         JR        NZ,FH.ADV1 IF REVERSE, JUST ADJUST Y 
         INC       H          MOVE TO NEXT CHAR. POSITION 
         INC       H             IN THE X DIRECTION 
         SET       7,H
         LD        (DMAA),HL
         LD        BC,0008
         LD        HL,(XREG)
         ADD       HL,BC
         LD        A,H
         AND       01 
         LD        H,A
         LD        (XREG),HL
         RET
FH.ADV1  EQU       *
         SET       7,H
         LD        (DMAA),HL
         RET
         EJECT     FAST PLOT INVERSE (HORIZONTAL) 
**********
*        FAST PLOT INVERSE HORIZONTAL 
**********
         SPACE     2
FPLOTI   EQU       *
         LD        A,(DE)     COMPLEMENT CHAR. DATA 
         CPL                    BEFORE WRITING TO SCREEN
         LD        (HL),A 
         DEC       DE 
         DEC       HL 
         DEC       C
         JR        NZ,FPLOTI
         EX        DE,HL
         JP        FH.ADV 
         EJECT     FAST PLOT OVERSTRIKE WRITE(HOR.) 
**********
*        FAST PLOT OVERSTRIKE WRITE HORIZONTAL
**********
         SPACE     2
FPLOTOW  EQU       *
         LD        A,(DE)     CHAR. DATA .OR. WITH SCREEN 
         OR        (HL) 
         LD        (HL),A 
         DEC       DE 
         DEC       HL 
         DEC       C
         JR        NZ,FPLOTOW 
         EX        DE,HL
         JP        FH.ADV 
         EJECT     FAST PLOT OVERSTRIKE ERASE(HOR.) 
**********
*        FAST PLOT OVERSTRIKE ERASE HORIZONTAL
**********
         SPACE     2
FPLOTOE  EQU       *
         LD        A,(DE) 
         CPL
         AND       (HL) 
         LD        (HL),A 
         DEC       DE 
         DEC       HL 
         DEC       C
         JR        NZ,FPLOTOE 
         EX        DE,HL
         JP        FH.ADV 
         EJECT     HORIZONTAL PLOT NORMAL 
**********
*        HORIZONTAL PLOT NORMAL 
**********
         SPACE     2
HPLOTN   EQU       *
         EX        DE,HL
         LD        DE,(DMAA)
         LD        BC,0010H 
         LD        A,(BP) 
         OR        A
         JP        Z,FHPLOT   X AND Y ON BOUNDARY 
         AND       07H
         JR        NZ,HPN0
MHP1     EQU       *          ONLY Y OFF BOUNDARY 
         LDD
         JP        PO,H.ADV   CHAR DONE, POINT TO NEXT CHAR 
         LD        A,E
         INC       A
         JR        NZ,MHP1
         BIT       0,D
* /---   BLOCK      NORTHS     00 000   73/00/00  00.00 
         JR        Z,MHP1 
         INC       D
         INC       D
         SET       7,D
         JR        MHP1 
* 
HPN0     EQU       *          X AND Y OFF CHAR. BOUNDARIES
         EXX
         CALL      MASKS
         EXX
         PUSH      HL 
         POP       IX         IX HAS FWA OF CHAR. DATA
         LD        HL,(DMAA)  DISPLAY MEMORY ADDR.
         LD        DE,(DMA1)  DISPLAY MEMORY ADDR. NEXT COL.
         LD        B,10H      LOOP COUNT
HPN1     EQU       *
         EXX
         LD        A,(BP) 
         AND       07H
         LD        B,A
         LD        A,(IX+0) 
HPN2     EQU       *
         RLA
         RL        C
         DJNZ      HPN2 
* 
         AND       D
         LD        B,A
         LD        A,C
         AND       E
         LD        C,A
         EXX
         LD        A,(HL) 
         EXX
         AND       E
         OR        B
         EXX
         LD        (HL),A 
         LD        A,(DE) 
         EXX
         AND       D
         OR        C
         EXX
         EX        DE,HL
         LD        (HL),A 
         EX        DE,HL
         DEC       DE 
         DEC       HL 
         DEC       IX 
         DJNZ      HPN3 
         JP        H.ADV
HPN3     EQU       *
         LD        A,L
         INC       A
         JR        NZ,HPN1
         BIT       0,H
         JR        Z,HPN1 
         INC       H
         INC       H
         SET       7,H
         INC       D
         INC       D
         SET       7,D
         JP        HPN1 
         EJECT     HORIZONTAL PLOT INVERSE
**********
*        HORIZONTAL PLOT INVERSE
**********
         SPACE     2
HPLOTI   EQU       *
*                             DE HAS CHAR. FWA
         LD        HL,(DMAA)  HL HAS DISPLAY MEM. ADDR. 
         LD        BC,0010H 
         LD        A,(BP) 
         OR        A
         JP        Z,FPLOTI   X AND Y ON BOUNDARIES 
         AND       07H
         JR        NZ,HPI0
MHPI1    EQU       *          ONLY Y ON BOUNDARY
         LD        A,(DE)     COMPLEMENT CHAR. DATA 
         CPL
         LD        (HL),A 
         DEC       HL 
         DEC       DE 
         DEC       C
         JP        Z,H.ADV
         LD        A,L
         INC       A
         JR        NZ,MHPI1   CHECK FOR TOP OF SCREEN WRAP
         BIT       0,H
         JR        Z,MHPI1       IF SET, ADJUST X FOR WRAP
         INC       H
         INC       H
         SET       7,H
         JR        MHPI1      CONTINUE PLOTTING 
* 
HPI0     EQU       *           X AND Y OFF CHAR. BOUNDARIES 
         EXX
* /---   BLOCK      NORTHS     00 000   73/00/00  00.00 
         CALL      MASKS
         EXX
         PUSH      DE 
         POP       IX         IX HAS FWA OF CHAR. DATA
         LD        HL,(DMAA)  DISPLAY MEMORY ADDR.
         LD        DE,(DMA1)  DISPLAY MEMORY ADDR. NEXT COL.
         LD        B,10H      LOOP COUNT
HPI1     EQU       *
         EXX
         LD        A,(BP) 
         AND       07H
         LD        B,A
         LD        A,(IX+0) 
         CPL
HPI2     EQU       *
         RLA
         RL        C
         DJNZ      HPI2 
         AND       D
         LD        B,A
         LD        A,C
         AND       E
         LD        C,A
         EXX
         LD        A,(HL) 
         EXX
         AND       E
         OR        B
         EXX
         LD        (HL),A 
         LD        A,(DE) 
         EXX
         AND       D
         OR        C
         EXX
         EX        DE,HL
         LD        (HL),A 
         EX        DE,HL
         DEC       DE 
         DEC       HL 
         DEC       IX 
         DJNZ      HPI3 
         JP        H.ADV
HPI3     EQU       *
         LD        A,L
         INC       A
         JR        NZ,HPI1
         BIT       0,H
         JR        Z,HPI1 
         INC       H
         INC       H
         SET       7,H
         INC       D
         INC       D
         SET       7,D
         JP        HPI1 
         EJECT     HORIZONTAL OVERSTRIKE WRITE
**********
*        HORIZONTAL OVERSTRIKE WRITE
**********
         SPACE     2
HPLOTOW  EQU       *
*                             DE HAS CHAR. FWA
         LD        HL,(DMAA)  HL HAS DISPLAY MEM. ADDR. 
         LD        BC,0010H 
         LD        A,(BP) 
         OR        A
         JP        Z,FPLOTOW  X AND Y ON BOUNDARY 
         AND       07H
         JR        NZ,HPOW0 
MHPOW1   EQU       *          ONLY Y ON BOUNDARY
         LD        A,(DE)     CHAR. DATA .OR. WITH SCREEN 
         OR        (HL) 
         LD        (HL),A 
         DEC       HL 
         DEC       DE 
         DEC       C
         JP        Z,H.ADV
         LD        A,L
         INC       A
         JR        NZ,MHPOW1   CHECK FOR TOP OF SCREEN WRAP 
         BIT       0,H
         JR        Z,MHPOW1       IF SET, ADJUST X FOR WRAP 
         INC       H
         INC       H
         SET       7,H
         JR        MHPOW1      CONTINUE PLOTTING
HPOW0    EQU       *           X AND Y OFF CHAR. BOUNDARIES 
         EXX
         CALL      MASKS
         EXX
         PUSH      DE 
         POP       IX         IX HAS FWA OF CHAR. DATA
         LD        HL,(DMAA)  DISPLAY MEMORY ADDR.
* /---   BLOCK      NORTHS     00 000   73/00/00  00.00 
         LD        DE,(DMA1)  DISPLAY MEMORY ADDR. NEXT COL.
         LD        B,10H      LOOP COUNT
HPOW1    EQU       *
         EXX
         LD        A,(BP) 
         AND       07H
         LD        B,A
         LD        A,(IX+0) 
HPOW2    EQU       *
         RLA
         RL        C
         DJNZ      HPOW2
         AND       D
         LD        B,A
         LD        A,C
         AND       E
         LD        C,A
         EXX
         LD        A,(HL) 
         EXX
         OR        B
         EXX
         LD        (HL),A 
         LD        A,(DE) 
         EXX
         OR        C
         EXX
         EX        DE,HL
         LD        (HL),A 
         EX        DE,HL
         DEC       DE 
         DEC       HL 
         DEC       IX 
         DJNZ      HPOW3
         JP        H.ADV
HPOW3    EQU       *
         LD        A,L
         INC       A
         JR        NZ,HPOW1 
         BIT       0,H
         JR        Z,HPOW1
         INC       H
         INC       H
         SET       7,H
         INC       D
         INC       D
         SET       7,D
         JP        HPOW1
         EJECT     HORIZONTAL OVERSTRIKE ERASE
**********
*        HORIZONTAL OVERSTRIKE ERASE
**********
         SPACE     2
HPLOTOE  EQU       *
*                             DE HAS CHAR. FWA
         LD        HL,(DMAA)  HL HAS DISPLAY MEM. ADDR. 
         LD        BC,0010H 
         LD        A,(BP) 
         OR        A
         JP        Z,FPLOTOE  X AND Y ON BOUNDARIES 
         AND       07H
         JR        NZ,HPOE0 
MHPOE1   EQU       *          ONLY Y ON BOUNDARY
         LD        A,(DE)     CHAR. DATA .OR. WITH SCREEN 
         CPL
         AND       (HL) 
         LD        (HL),A 
         DEC       HL 
         DEC       DE 
         DEC       C
         JP        Z,H.ADV
         LD        A,L
         INC       A
         JR        NZ,MHPOE1   CHECK FOR TOP OF SCREEN WRAP 
         BIT       0,H
         JR        Z,MHPOE1       IF SET, ADJUST X FOR WRAP 
         INC       H
         INC       H
         SET       7,H
         JR        MHPOE1      CONTINUE PLOTTING
HPOE0    EQU       *          X AND Y ON CHAR. BOUNDARIES 
         EXX
         CALL      MASKS
         EXX
         PUSH      DE 
         POP       IX         IX HAS FWA OF CHAR. DATA
         LD        HL,(DMAA)  DISPLAY MEMORY ADDR.
         LD        DE,(DMA1)  DISPLAY MEMORY ADDR. NEXT COL.
         LD        B,10H      LOOP COUNT
HPOE1    EQU       *
         EXX
         LD        A,(BP) 
         AND       07H
         LD        B,A
         LD        A,(IX+0) 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         CPL
HPOE2    EQU       *
         RLA
         RL        C
         DJNZ      HPOE2
         AND       D
         OR        E
         LD        B,A
         LD        A,C
         AND       E
         OR        D
         LD        C,A
         EXX
         LD        A,(HL) 
         EXX
         AND       B
         EXX
         LD        (HL),A 
         LD        A,(DE) 
         EXX
         AND       C
         EXX
         EX        DE,HL
         LD        (HL),A 
         EX        DE,HL
         DEC       DE 
         DEC       HL 
         DEC       IX 
         DJNZ      HPOE3
         JP        H.ADV
HPOE3    EQU       *
         LD        A,L
         INC       A
         JR        NZ,HPOE1 
         BIT       0,H
         JR        Z,HPOE1
         INC       H
         INC       H
         SET       7,H
         INC       D
         INC       D
         SET       7,D
         JP        HPOE1
         SPACE     2
**********
*        HORIZONTAL ADVANCE 
**********
         SPACE     2
H.ADV    EQU       *
         LD        A,(M.CCR)
         BIT       6,A
         RET       NZ         IF REVERSE, RETURN
         LD        HL,(XREG)  OTHERWISE ADVANCE 
         LD        DE,0008       BY ONE CHAR. WIDTH 
         ADD       HL,DE
         JP        R.OUTX 
         EJECT     VERTICAL FPLOT NORMAL
**********
*        FAST PLOT NORMAL VERTICAL
**********
         SPACE     2
*        THIS CHARACTER GENERATOR WORKS FOR VERTICAL
*        CHARACTERS WHICH ARE ON THE X BOUNDARY.
*        THE Y BOUNDARY WILL BE CHECKED DURING EXECUTION. 
*        VDMA1 AND VDMA2 ARE WRITTEN TO IN THAT ORDER.
*        EACH IS DECREMENTED BY 1 AND SCREEN WRAP IS
*        CHECKED.  THIS IS REPEATED 8 TIMES FOR  THE
*        16 BYTES MAKING UP THE CHARACTER.
         SPACE     2
FVPLTN   EQU       *
         LD        B,08 
*                             IX-LWA OF ROTATED CHAR DATA 
         LD        HL,(VDMA1) 
         LD        DE,(VDMA2) 
FVN.0    EQU       *
         LD        A,(IX+0) 
         LD        (HL),A 
         LD        A,(IX-1) 
         LD        (DE),A 
         DEC       B
         JR        Z,FVN.1
         DEC       IX 
         DEC       IX 
         DEC       HL 
         DEC       DE 
         CALL      V.WRAP 
         JR        FVN.0
FVN.1    EQU       *
         CALL      V.ADV
         RET
         EJECT     FAST PLOT INVERSE VERTICAL 
**********
*        FAST PLOT INVERSE VERTICAL 
**********
         SPACE     2
*        THIS CHARACTER GENERATOR WORKS FOR VERTICAL
*        CHARACTERS WHICH ARE ON THE X BOUNDARY.
* /---   BLOCK      NORTHS     00 000   73/00/00  00.00 
*        THE Y BOUNDARY WILL BE CHECKED DURING EXECUTION. 
*        VDMA1 AND VDMA2 ARE WRITTEN TO IN THAT ORDER.
*        EACH IS DECREMENTED BY 1 AND SCREEN WRAP IS
*        CHECKED.  THIS IS REPEATED 8 TIMES FOR  THE
*        16 BYTES MAKING UP THE CHARACTER.
         SPACE     2
FVPLTI   EQU       *
         LD        B,08 
*                             IX-LWA OF ROTATED CHAR DATA 
         LD        HL,(VDMA1) 
         LD        DE,(VDMA2) 
FVI.0    EQU       *
         LD        A,(IX+0) 
         CPL
         LD        (HL),A 
         LD        A,(IX-1) 
         CPL
         LD        (DE),A 
         DEC       B
         JR        Z,FVI.1
         DEC       IX 
         DEC       IX 
         DEC       HL 
         DEC       DE 
         CALL      V.WRAP 
         JR        FVI.0
FVI.1    EQU       *
         CALL      V.ADV
         RET
         EJECT     FAST OVERSTRIKE WRITE VERTICAL 
**********
*        FAST OVERSTRIKE WRITE VERTICAL 
********* 
         SPACE     2
*        THIS CHARACTER GENERATOR WORKS FOR VERTICAL
*        CHARACTERS WHICH ARE ON THE X BOUNDARY.
*        THE Y BOUNDARY WILL BE CHECKED DURING EXECUTION. 
*        VDMA1 AND VDMA2 ARE WRITTEN TO IN THAT ORDER.
*        EACH IS DECREMENTED BY 1 AND SCREEN WRAP IS
*        CHECKED.  THIS IS REPEATED 8 TIMES FOR  THE
*        16 BYTES MAKING UP THE CHARACTER.
         SPACE     2
FVPLTOW  EQU       *
         LD        B,08 
*                             IX-LWA OF ROTATED CHAR DATA 
         LD        HL,(VDMA1) 
         LD        DE,(VDMA2) 
FVOW.0   EQU       *
         LD        A,(IX+0) 
         OR        (HL) 
         LD        (HL),A 
         LD        A,(IX-1) 
         EX        DE,HL
         OR        (HL) 
         LD        (HL),A 
         EX        DE,HL
         DEC       B
         JR        Z,FVOW.1 
         DEC       IX 
         DEC       IX 
         DEC       HL 
         DEC       DE 
         CALL      V.WRAP 
         JR        FVOW.0 
FVOW.1   EQU       *
         CALL      V.ADV
         RET
         EJECT     FAST OVERSTRIKE ERASE VERTICAL 
**********
*        FAST OVERSTRIKE ERASE VERTICAL 
**********
         SPACE     2
*        THIS CHARACTER GENERATOR WORKS FOR VERTICAL
*        CHARACTERS WHICH ARE ON THE X BOUNDARY.
*        THE Y BOUNDARY WILL BE CHECKED DURING EXECUTION. 
*        VDMA1 AND VDMA2 ARE WRITTEN TO IN THAT ORDER.
*        EACH IS DECREMENTED BY 1 AND SCREEN WRAP IS
*        CHECKED.  THIS IS REPEATED 8 TIMES FOR  THE
*        16 BYTES MAKING UP THE CHARACTER.
         SPACE     2
FVPLTOE  EQU       *
         LD        B,08 
*                             IX-LWA OF ROTATED CHAR DATA 
         LD        HL,(VDMA1) 
* /---   BLOCK      NORTHS     00 000   73/00/00  00.00 
         LD        DE,(VDMA2) 
FVOE.0   EQU       *
         LD        A,(IX+0) 
         CPL
         AND       (HL) 
         LD        (HL),A 
         LD        A,(IX-1) 
         EX        DE,HL
         CPL
         AND       (HL) 
         LD        (HL),A 
         EX        DE,HL
         DEC       B
         JR        Z,FVOE.1 
         DEC       IX 
         DEC       IX 
         DEC       HL 
         DEC       DE 
         CALL      V.WRAP 
         JR        FVOE.0 
FVOE.1   EQU       *
         CALL      V.ADV
         RET
         EJECT     VERTICAL CHARACTER DATA ROTATION 
*        VERRT- VERTICAL ROTATION ROUTINE 
*        THIS ROUTINE MOVES THE CURRENT CHARACTER DATA
*        TO A TEMPORARY STORAGE AREA, SAVE4F.  THEN IT
*        ROTATES 16 BYTES OF CHARACTER DATA TO A TEMPORARY
*        STORAGE AREA, SAVE5F.  'THE ALGORITHM STORES BACK
*        INTO SAVE4F AREA THE INTERMEDIATE ROTATES WHICH
*        IS WHY THE INITIAL CHARACTER DATA MOVE IS NEEDED.
*        THIS ROTATION FACILITATES  THE VERTICAL
*        CHARACTER GENERATION.
*           ENTRY- DE HAS LWA OF CHARACTER DATA 
*           EXIT- IX HAS LWA OF ROTATED CHAR. DATA, SAVE5F
         SPACE     2
VERRT    EQU       *
         EX        DE,HL      MOVE CHARACTER DATA 
         LD        DE,SAVE4F     TO TEMPORARY STORE AREA
         LD        BC,0010H 
         LDDR 
         EX        DE,HL
         LD        BC,0008
         ADD       HL,BC      IX HAS LWA-8 OF CHAR. DATA
         PUSH      HL            C RETAINS OUTER LOOP COUNT 
         POP       IX 
VERRT.0  EQU       *
         LD        HL,SAVE5F  FWA OF TEMPORARY CHAR. STORE
         LD        B,08 
VERRT.1  EQU       *
         LD        A,(IX+8) 
         RRA
         LD        (IX+8),A 
         RL        (HL) 
         DEC       HL 
         LD        A,(IX+0) 
         RRA
         LD        (IX+0),A 
         RL        (HL) 
         DEC       HL 
         DJNZ      VERRT.1    INNER LOOP 8 TIMES
         DEC       IX 
         DEC       C
         JR        NZ,VERRT.0    OUTER LOOP 8 TIMES 
         LD        HL,SAVE5F  LOAD IX WITH LWA OF 
         PUSH      HL            OF ROTATED CHAR. DATA
         POP       IX            FOR CHARACTER GENERATORS 
         RET
         EJECT     VERTICAL PLOT ADDRESS ADJUST/ADVANCE 
**********
*        VERTICAL PLOT ADDRESS ADJUST 
**********
         SPACE     2
VADR.ADJ EQU       *
         LD        HL,(DMAA)
         DEC       H
         DEC       H
         SET       7,H
         LD        (VDMA1),HL   POINT TO WORD LEFT OF DMAA
         DEC       H
         DEC       H
         SET       7,H
         LD        (VDMA2),HL   POINT TO WORD LEFT OF VDMA1 
         RET
         SPACE     2
**********
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
*        VERTICAL CHARACTER GENERATOR ADVANCE ROUTINE 
********* 
V.ADV    EQU       *
         LD        A,(M.CCR)
         BIT       6,A
         RET       NZ         IF REVERSE, RETURN
         LD        DE,0008
         CALL      R.INPY 
         ADD       HL,DE
         CALL      R.OUTY 
         RET
         EJECT     VERTICAL SCREEN TOP WRAP CHECK 
**********
*        VERTICAL WRAP ROUTINE
*                  CHECKS TO SEE IF SCREEN TOP HAS BEEN 
*                  REACHED AND ADJUSTS VDMA1 AND VDMA2
*                  IF SO. 
*           ENTRY- DE HAS CURRENT DISPLAY MEM. ADDR.
**********
         SPACE     2
V.WRAP   EQU       *
         LD        A,E
         INC       A
         RET       NZ 
         BIT       0,D
         RET       Z
         INC       D
         INC       D
         INC       H
         INC       H
         SET       7,D
         SET       7,H
         RET
         EJECT     VERTICAL BIT ROTATE
**********
*        VERTICAL PLOT NORMAL 
**********
VPLOTN   EQU       *
         CALL      VERRT      ROTATE CHAR DATA TO SAVE5F
         CALL      VADR.ADJ   ADJUST SCREEN ADDRESSES 
         LD        A,(BP)        FOR VERTICAL WRITING 
         AND       07 
         JP        Z,FVPLTN   ON X BOUNDARY, FAST PLOT
* 
*        OTHERWISE CHARACTER PLOTTING IS OVER THREE 
*        EIGHT BIT WORDS.  ROW BY ROW, CHARACTER DATA 
*        ON THE SCREEN WITHIN THE RIGHTMOST AND LEFTMOST
*        BYTES MUST BE LEFT UNDISTURBED WHILE THE NEW 
*        CHARACTER IS WRITTEN IN NORMAL MODE TO THE 
*        16 BITS MAKING UP THE CHARACTER HEIGHT.  THE 
*        RIGHT BYTE AND RIGHT OF MIDDLE BYTE ARE WRITTEN TO 
*        FIRST THEN THE LEFT BYTE AND LEFTMOST PART OF
*        MIDDLE BYTE ARE WRITTEN TO ON A ROW BY ROW BASIS 
*        FOR THE 8 ROWS MAKING UP THE CHARACTER WIDTH.
* 
         EXX
         CALL      MASKS      DE - MASKS FOR CHAR DATA
*                                  AND DISPLAY WORDS
         LD        BC,0802H   B-CHAR WIDTH COUNT, C-COLUMNS 
         EXX
         LD        HL,SAVE5F  LWA OF VERTICAL CHAR DATA 
         PUSH      HL 
         POP       IX 
         LD        HL,(DMAA)  RIGHTMOST BYTE OF VERTICALS 
         LD        DE,(VDMA1) MIDDLE BYTE OF VERTICALS
VNORM.0  EQU       *
         LD        A,(BP) 
         AND       07 
         LD        B,A
         LD        A,(IX+0) 
VNORM.1  EQU       *
         RLA
         RL        C
         DJNZ      VNORM.1
         EXX
         AND       D
         EXX
         LD        B,A
         LD        A,(DE) 
         EXX
         AND       E
         EXX
         OR        B
         LD        (DE),A 
         LD        A,C
* /---   BLOCK      NORTHS     00 000   73/00/00  00.00 
         EXX
         AND       E
         EXX
         LD        B,A
         LD        A,(HL) 
         EXX
         AND       D
         EXX
         OR        B
         LD        (HL),A 
         EXX
         DEC       B          REPEAT FOR CHAR WIDTH OF 8
         JR        Z,VNORM.2
         EXX
         DEC       IX 
         DEC       IX 
         DEC       HL 
         DEC       DE 
         CALL      V.WRAP 
         JR        VNORM.0
VNORM.2  EQU       *
         LD        B,08       RESET INNER LOOP COUNT
         DEC       C
         EXX
         JR        Z,VNORM.3
         LD        HL,(VDMA1) REPEAT FOR LEFTMOST BYTE
         LD        DE,(VDMA2)    AND LEFT OF MIDDLE BYTE
         LD        BC,000DH 
         ADD       IX,BC
         JR        VNORM.0
VNORM.3  EQU       *
         CALL      V.ADV
         RET
         EJECT     VERTICAL PLOT INVERSE
**********
*        VERTICAL PLOT INVERSE
**********
         SPACE     2
VPLOTI   EQU       *
         CALL      VADR.ADJ 
         CALL      VERRT      IX - LWA OF ROTATED CHAR DATA 
         LD        A,(BP) 
         AND       07 
         JP        Z,FVPLTI 
* 
*        OTHERWISE CHARACTER PLOTTING IS OVER THREE 
*        EIGHT BIT WORDS.  ROW BY ROW, CHARACTER DATA 
*        ON THE SCREEN WITHIN THE RIGHTMOST AND LEFTMOST
*        BYTES MUST BE LEFT UNDISTURBED WHILE THE NEW 
*        CHARACTER IS WRITTEN IN NORMAL MODE TO THE 
*        16 BITS MAKING UP THE CHARACTER HEIGHT.  THE 
*        RIGHT BYTE AND RIGHT OF MIDDLE BYTE ARE WRITTEN TO 
*        FIRST THEN THE LEFT BYTE AND LEFTMOST PART OF
*        MIDDLE BYTE ARE WRITTEN TO ON A ROW BY ROW BASIS 
*        FOR THE 8 ROWS MAKING UP THE CHARACTER WIDTH.
* 
         EXX
         CALL      MASKS      DE - MASKS FOR CHAR DATA
*                                  AND DISPLAY WORDS
         LD        BC,0802H   B-CHAR WIDTH COUNT, C-COLUMNS 
         EXX
*                             IX-LWA ROTATED CHAR DATA
         LD        HL,(DMAA)  RIGHTMOST BYTE OF VERTICALS 
         LD        DE,(VDMA1) MIDDLE BYTE OF VERTICALS
VINV.0   EQU       *
         LD        A,(BP) 
         AND       07 
         LD        B,A
         LD        A,(IX+0) 
         CPL
VINV.1   EQU       *
         RLA
         RL        C
         DJNZ      VINV.1 
         EXX
         AND       D
         EXX
         LD        B,A
         LD        A,(DE) 
         EXX
         AND       E
         EXX
         OR        B
         LD        (DE),A 
         LD        A,C
         EXX
         AND       E
         EXX
         LD        B,A
         LD        A,(HL) 
         EXX
         AND       D
* /---   BLOCK      NORTHS     00 000   73/00/00  00.00 
         EXX
         OR        B
         LD        (HL),A 
         EXX
         DEC       B          REPEAT FOR CHAR WIDTH OF 8
         JR        Z,VINV.2 
         EXX
         DEC       IX 
         DEC       IX 
         DEC       HL 
         DEC       DE 
         CALL      V.WRAP 
         JR        VINV.0 
VINV.2   EQU       *
         LD        B,08       RESET INNER LOOP COUNT
         DEC       C
         EXX
         JR        Z,VINV.3 
         LD        HL,(VDMA1) REPEAT FOR LEFTMOST BYTE
         LD        DE,(VDMA2)    AND LEFT OF MIDDLE BYTE
         LD        BC,000DH 
         ADD       IX,BC
         JR        VINV.0 
VINV.3   EQU       *
         CALL      V.ADV
         RET
         EJECT     VERTICAL PLOT OVERSTRIKE WRITE 
**********
*        VERTICAL PLOT OVERSTRIKE WRITE 
**********
         SPACE     2
VPLOTOW  EQU       *
         CALL      VADR.ADJ 
         CALL      VERRT      IX - LWA OF ROTATED CHAR DATA 
         LD        A,(BP) 
         AND       07 
         JP        Z,FVPLTOW
* 
*        OTHERWISE CHARACTER PLOTTING IS OVER THREE 
*        EIGHT BIT WORDS.  ROW BY ROW, CHARACTER DATA 
*        ON THE SCREEN WITHIN THE RIGHTMOST AND LEFTMOST
*        BYTES MUST BE LEFT UNDISTURBED WHILE THE NEW 
*        CHARACTER IS WRITTEN IN NORMAL MODE TO THE 
*        16 BITS MAKING UP THE CHARACTER HEIGHT.  THE 
*        RIGHT BYTE AND RIGHT OF MIDDLE BYTE ARE WRITTEN TO 
*        FIRST THEN THE LEFT BYTE AND LEFTMOST PART OF
*        MIDDLE BYTE ARE WRITTEN TO ON A ROW BY ROW BASIS 
*        FOR THE 8 ROWS MAKING UP THE CHARACTER WIDTH.
* 
         EXX
         CALL      MASKS      DE - MASKS FOR CHAR DATA
*                                  AND DISPLAY WORDS
         LD        BC,0802H   B-CHAR WIDTH COUNT, C-COLUMNS 
         EXX
*                             IX-LWA OF ROTATED CHAR DATA 
         LD        HL,(DMAA)  RIGHTMOST BYTE OF VERTICALS 
         LD        DE,(VDMA1) MIDDLE BYTE OF VERTICALS
VOW.0    EQU       *
         LD        A,(BP) 
         AND       07 
         LD        B,A
         LD        A,(IX+0) 
VOW.1    EQU       *
         RLA
         RL        C
         DJNZ      VOW.1
         EXX
         AND       D
         EXX
         EX        DE,HL
         OR        (HL) 
         EX        DE,HL
         LD        (DE),A 
         LD        A,C
         EXX
         AND       E
         EXX
         OR        (HL) 
         LD        (HL),A 
         EXX
         DEC       B          REPEAT FOR CHAR WIDTH OF 8
         JR        Z,VOW.2
         EXX
         DEC       IX 
         DEC       IX 
         DEC       HL 
         DEC       DE 
         CALL      V.WRAP 
* /---   BLOCK      NORTHS     00 000   73/00/00  00.00 
         JR        VOW.0
VOW.2    EQU       *
         LD        B,08       RESET INNER LOOP COUNT
         DEC       C
         EXX
         JR        Z,VOW.3
         LD        HL,(VDMA1) REPEAT FOR LEFTMOST BYTE
         LD        DE,(VDMA2)    AND LEFT OF MIDDLE BYTE
         LD        BC,000DH 
         ADD       IX,BC
         JR        VOW.0
VOW.3    EQU       *
         CALL      V.ADV
         RET
         EJECT     VERTICAL OVERSTRIKE ERASE
**********
*        VERTICAL OVERSTRIKE ERASE
**********
         SPACE     2
VPLOTOE  EQU       *
         CALL      VADR.ADJ 
         CALL      VERRT      IX - LWA OF ROTATED CHAR DATA 
         LD        A,(BP) 
         AND       07 
         JP        Z,FVPLTOE
* 
*        OTHERWISE CHARACTER PLOTTING IS OVER THREE 
*        EIGHT BIT WORDS.  ROW BY ROW, CHARACTER DATA 
*        ON THE SCREEN WITHIN THE RIGHTMOST AND LEFTMOST
*        BYTES MUST BE LEFT UNDISTURBED WHILE THE NEW 
*        CHARACTER IS WRITTEN IN NORMAL MODE TO THE 
*        16 BITS MAKING UP THE CHARACTER HEIGHT.  THE 
*        RIGHT BYTE AND RIGHT OF MIDDLE BYTE ARE WRITTEN TO 
*        FIRST THEN THE LEFT BYTE AND LEFTMOST PART OF
*        MIDDLE BYTE ARE WRITTEN TO ON A ROW BY ROW BASIS 
*        FOR THE 8 ROWS MAKING UP THE CHARACTER WIDTH.
* 
         EXX
         CALL      MASKS      DE - MASKS FOR CHAR DATA
*                                  AND DISPLAY WORDS
         LD        BC,0802H   B-CHAR WIDTH COUNT, C-COLUMNS 
         EXX
*                             IX-LWA OF ROTATED CHAR DATA 
         LD        HL,(DMAA)  RIGHTMOST BYTE OF VERTICALS 
         LD        DE,(VDMA1) MIDDLE BYTE OF VERTICALS
VOE.0    EQU       *
         LD        A,(BP) 
         AND       07 
         LD        B,A
         LD        A,(IX+0) 
         CPL
VOE.1    EQU       *
         RLA
         RL        C
         DJNZ      VOE.1
         EXX
         AND       D
         OR        E
         EXX
         EX        DE,HL
         AND       (HL) 
         EX        DE,HL
         LD        (DE),A 
         LD        A,C
         EXX
         AND       E
         OR        D
         EXX
         AND       (HL) 
         LD        (HL),A 
         EXX
         DEC       B          REPEAT FOR CHAR WIDTH OF 8
         JR        Z,VOE.2
         EXX
         DEC       IX 
         DEC       IX 
         DEC       HL 
         DEC       DE 
         CALL      V.WRAP 
         JR        VOE.0
VOE.2    EQU       *
         LD        B,08       RESET INNER LOOP COUNT
         DEC       C
         EXX
         JR        Z,VOE.3
         LD        HL,(VDMA1) REPEAT FOR LEFTMOST BYTE
         LD        DE,(VDMA2)    AND LEFT OF MIDDLE BYTE
* /---   BLOCK      NORTHS     00 000   73/00/00  00.00 
         LD        BC,000DH 
         ADD       IX,BC
         JR        VOE.0
VOE.3    EQU       *
         CALL      V.ADV
         RET
         EJECT     BLOCK WRITE/ERASE
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
* 
*        BLOCK WRITE/ERASE
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     2
* 
ABLOCK   EQU       *
         CALL      GETXY      GET AN X AND Y COORD
         LD        A,(MODE4CNT) CHECK WHICH SET OF COORDS 
         XOR       1
         LD        (MODE4CNT),A 
         JR        Z,ABLOCK1
 
         LD        (BLOCKX),HL FIRST SET OF COORDS
         LD        (BLOCKY),DE
         RET
 
ABLOCK1  LD        (XEND),HL  SECOND SET OF COORDS
         LD        (YEND),DE
         LD        HL,BLOCKX  POINT TO COORDS 
 
*        USER ENTRY POINT 
BLOCK    EQU       *
         LD        DE,BLOCKX  STORE  USER'7S COORDINATES
         LD        BC,0008H      TO PROGRAM MEMORY
         LDIR                    STARTING AT BLOCKX 
* 
         LD        A,(BLOCKX) SAVE1 _ MASK FOR 1ST X COORD. 
         AND       07 
         CALL      MASKS0 
         EX        DE,HL
         LD        (SAVEL),HL 
* 
         LD        A,(XEND)   SAVE2 _ MASK FOR 2ND X COORD. 
         AND       07 
         CALL      MASKS0 
         EX        DE,HL
         LD        (SAVER),HL 
* 
         LD        HL,BLOCKX+1   ENSURE EACH COORDINATE 
         LD        B,04              IS 9 BITS MAX. 
         LD        C,01 
* 
BLOCK0   EQU       *
         LD        A,(HL) 
         AND       C
         LD        (HL),A 
         INC       HL 
         INC       HL 
         DJNZ      BLOCK0 
* 
MODE4.B  EQU       *
         LD        C,00 
         LD        HL,(BLOCKX)
         CALL      CALDELX    CALCULATE DELTA X 
         LD        HL,(BLOCKY)
         CALL      CALDELY    CALCULATE DELTA Y 
         BIT       4,C        IF DELTA Y IS POSITIVE
         LD        HL,(YEND)   USE YEND AS BEGINNING
         JR        Z,MODE4.C     Y COORD. 
         LD        HL,(BLOCKY)   OTHERWISE, USE BLOCKY
* 
MODE4.C  EQU       *
         CALL      R.OUTY     THIS WILL COMPLEMENT Y
* 
         BIT       3,C        IF DELTA X IS POSITIVE
         LD        HL,(BLOCKX)   USE BLOCKX AS BEGINNING
         LD        BC,(SAVEL)    XCOORD.
         LD        DE,(SAVER) 
         JR        Z,MODE4.D
         LD        HL,(XEND)  OTHERWISE, USE XEND 
         LD        BC,(SAVER) 
         LD        DE,(SAVEL) 
* 
MODE4.D  EQU       *
         SLA       D
         LD        A,D
         LD        (RMASK),A
         LD        A,B
         LD        (LMASK),A
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        A,C
         XOR       D
         LD        (MMASK),A
         CALL      R.OUTX     SET BEGINNING X ON SCREEN 
         LD        BC,(YDELTA)
         LD        HL,(XDELTA)
         LD        A,(BP) 
         AND       07 
         LD        E,A
         LD        D,00 
         ADD       HL,DE      IS DELTA X + BP > 0 
         LD        DE,0007
         SBC       HL,DE
         JR        C,MODE4.E     LESS THAN 8 BIT WIDTH
         JR        NZ,MODE4.F    MORE THAN 8 BIT WIDTH
* 
MODE4.E  EQU       *
         LD        A,(MMASK)  *CASE 1* DELTA X WITHIN 8 BITS
         LD        D,A
         LD        HL,(DMAA)
         LD        A,(M.MODE) 
         BIT       0,A
         JP        Z,BLOCKES
         LD        A,D
         CPL
         LD        D,A
         JP        BLOCKWS
* 
MODE4.F  EQU       *
         LD        HL,(DMAA)
         EXX
         LD        DE,(XDELTA)   WORD COUNT _ DELTA X / 8 
         LD        A,E
         AND       07 
         LD        B,A
         SRL       D
         RR        E
         SRL       D
         RR        E
         SRL       E
         LD        A,(BP) 
         AND       07 
         ADD       A,B
         CP        08 
         JR        C,MODE4.G
         INC       E          GREATER THAN 0, WORD COUNT + 1
* 
MODE4.G  EQU       *
         EXX
         LD        A,(LMASK)
         LD        D,A
         LD        A,(M.MODE) 
         BIT       0,A
         JP        NZ,BLOCKW
* 
         LD        A,(LMASK)
         CPL
         LD        D,A
         JP        BLOCKE 
         EJECT     SHORT BLOCK WRITE/ERASE
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        SHORT BLOCK ERASE, LESS THAN ONE BYTE IN Y AXIS
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
BLOCKES  EQU       *
         LD        A,(HL)         LOAD DMA DATA 
         AND       D                AND MASK SAVE BITS
         LD        (HL),A 
* 
         LD        A,B              AND TEST
         OR        C                  ZERO COUNT
         JP        Z,BLK.EXIT     END OF PLOT 
         DEC       BC             DECREMENT LOOP COUNT
         INC       HL             INCREMENT ADDRESS 
         JR        BLOCKES
         SPACE     2
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        SHORT BLOCK WRITE, LESS THAN ONE BYTE IN Y AXIS
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
BLOCKWS  EQU       *
         LD        A,(HL)         LOAD DMA DATA 
         OR        D                WRITE 
         LD        (HL),A 
* 
         LD        A,B              AND TEST
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         OR        C                  ZERO COUNT
         JP        Z,BLK.EXIT     END OF PLOT 
         DEC       BC             DECREMENT LOOP COUNT
         INC       HL             INCREMENT ADDRESS 
         JR        BLOCKWS
         EJECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
*        BLOCK     ERASE
*        HL        DMA ADDRESS
*        D         MASK 
*        E         LINE COUNT 
*        BC        X DELTA
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     2
BLOCKE   EQU       *
         LD        A,(HL)         LOAD DMA DATA 
         AND       D                AND MASK SAVE BITS
         LD        (HL),A 
* 
         LD        A,B              AND TEST
         OR        C                  ZERO COUNT
         JR        Z,BLOCK1 
         DEC       BC             DECREMENT LOOP COUNT
         INC       HL             INCREMENT ADDRESS 
         JR        BLOCKE 
* 
BLOCK1   EQU       *
         LD        BC,(YDELTA)   LOAD WIDTH OF ERASE AREA 
         LD        HL,(DMAA)      LOAD REFRESH MEMORY ADDRESS 
         INC       H          DO NEXT COLUMN
         INC       H
         SET       7,H            REFRESH MEMORY ADDRESS BIT
         EXX
         DEC       E              DECREMENT LINE COUNT
         EXX
         JR        NZ,BLOCK3      DO NEXT LINE IF NON ZERO
* 
         LD        A,(RMASK)  ELSE LOAD MASK
         LD        D,A
* 
BLOCK2   EQU       *
         LD        A,(HL)         LOAD DMA DATA 
         AND       D                AND MASK SAVE BITS
         LD        (HL),A 
* 
         LD        A,B              AND TEST
         OR        C                  ZERO COUNT
         JR        Z,BLK.EXIT     END OF PLOT 
         DEC       BC             DECREMENT LOOP COUNT
         INC       HL             INCREMENT ADDRESS 
         JR        BLOCK2 
* 
BLOCK3   EQU       *
         LD        D,H
         LD        E,L
         LD        (DMAA),HL      STORE NEXT LINE ADDRESS 
         LD        (HL),00H       ERASE FIRST CELL
         LD        A,B
         OR        C              TEST FOR SINGLE DOT WIDTH 
         JR        Z,BLOCK1       SINGLE DOT
* 
         INC       DE             INCREMENT DESTINATION ADDRES
         LDIR                     ERASE LINE
         JR        BLOCK1         TEST FOR LAST LINE
         EJECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        BLOCK WRITE
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     2
BLOCKW   EQU       *
         LD        A,(HL)         LOAD DMA DATA 
         OR        D                WRITE 
         LD        (HL),A 
* 
         LD        A,B              AND TEST
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         OR        C                  ZERO COUNT
         JR        Z,BLOCKW1
         DEC       BC             DECREMENT LOOP COUNT
         INC       HL             INCREMENT ADDRESS 
         JR        BLOCKW 
* 
BLOCKW1  EQU       *
         LD        BC,(YDELTA)   LOAD WIDTH OF WRITE AREA 
         LD        HL,(DMAA)      LOAD REFRESH MEMORY ADDRESS 
         INC       H
         INC       H          DO NEXT COLUMN
         SET       7,H            REFRESH MEMORY ADDRESS BIT
         EXX
         DEC       E              DECREMENT LINE COUNT
         EXX
         JR        NZ,BLOCKW3     DO NEXT LINE IF NON ZERO
* 
         LD        A,(RMASK)  ELSE  LOAD MASK 
         CPL
         LD        D,A
* 
BLOCKW2  EQU       *
         LD        A,(HL)         LOAD DMA DATA 
         OR        D                WRITE 
         LD        (HL),A 
* 
         LD        A,B              AND TEST
         OR        C                  ZERO COUNT
         JR        Z,BLK.EXIT     END OF PLOT 
         DEC       BC             DECREMENT LOOP COUNT
         INC       HL             INCREMENT ADDRESS 
         JR        BLOCKW2
* 
BLOCKW3  EQU       *
         LD        D,H
         LD        E,L
         LD        (DMAA),HL      STORE NEXT LINE ADDRESS 
         LD        (HL),0FFH      STORE ONES IN DMA 
         LD        A,B
         OR        C              TEST FOR SINGLE DOT WIDTH 
         JR        Z,BLOCKW1      SINGLE DOT
* 
         INC       DE 
         LDIR 
         JR        BLOCKW1        TEST FOR LAST LINE
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        BLOCK WRITE/ERASE EXIT 
*        X COORDINATE IS SET TO FIRST X COORDINATE RECEIVED 
*        Y COORDINATE IS SET TO FIRST Y COORDINATE 7INUS 15 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     2
BLK.EXIT EQU       *
         LD        HL,(BLOCKX)    LOAD FIRST X COORDINATE 
         CALL      OUTX             AND SET REFRESH ADDRESS 
         LD        HL,(BLOCKY)    LOAD FIRST Y COORDINATE 
         LD        DE,-15         LOAD NEGATIVE FIFTEEN 
         ADD       HL,DE            AND ADD TO Y COORDINATE 
         CALL      OUTY             AND SET REFRESH ADDRESS 
         RET                      EXIT TO CALLER
********* 
* GET X AND Y COORDINATES.
* POP RETURNS ARE EXECUTED UNTIL LOW X BYTE IS RECEIVED.
* THEN A NORMAL RETURN IS EXECUTED WITH THE X COORDINATE
* IN HL AND THE Y COORDINATE IN DE. 
********* 
GETXY    EQU       *
         LD        A,C        RESTORE  DATA 
         LD        HL,NBYTES  INCR. NUMBER OF INPUTS
         INC       (HL) 
         AND       60H        IF CHAR AND 60H=20H, HI Y 
         CP        20H
         JR        NZ,LOYCHK  OTHERWISE, CHECK FOR LO Y 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        A,1FH      HIGH=(CHAR-32)*32 
         AND       C
         LD        L,A
         LD        H,00 
         ADD       HL,HL
         ADD       HL,HL
         ADD       HL,HL
         ADD       HL,HL
         ADD       HL,HL      HL=HIGH 
         LD        A,(NBYTES) IF THIS INPUT IS FIRST
         CP        01         IN SEQ. IT IS HIGH Y BYE
         JR        Z,HIYBYTE
         LD        (HIX),HL   OTHERWISE, IT IS HIGH X 
         POP       AF         POP AND RET TO IDLE 
         RET
* 
HIYBYTE  EQU       *
         LD        (HIY),HL 
         POP       AF 
         RET
LOYCHK   EQU       *
         CP        60H        IF CHAR AND 60H=60H, LO Y 
         JR        NZ,LOXCHK  OTHERWISE, CHECK FOR LOW X
         LD        A,C
         AND       1FH
         LD        (LOY),A    LOY=(CHAR-32) 
         POP       AF         POP AND RET TO IDLE 
         RET
* 
LOXCHK   EQU       *
         CP        40H        IF CHAR AND 60H=40H, LO X 
         JR        NZ,ERR     ERR RETURN TO IDLE DEFAULT
         LD        A,C
         AND       1FH        LOX=(CHAR-32) 
         LD        (LOX),A
         LD        HL,(HIX) 
         OR        L
         LD        L,A
         EX        DE,HL      DE HAS X COORD
         LD        A,(LOY)
         LD        HL,(HIY) 
         OR        L
         LD        L,A
         EX        DE,HL      HL HAS X COORD
*                             DE HAS Y COORD
         XOR       A          CLEAR COMMAND MODE FLAG 
         LD        (CMODE),A
         LD        (NBYTES),A    SET NINPUTS TO 0 
         LD        A,(SCALEFG)    LOAD SCALE/NO SCALE FLAG
         RRA
         RET       C          IF SET, COORDS AS IS
* 
         SRA       H          OTHERWISE, SCALE BY 
         RR        L            A FACTOR OF 2 
         SRA       D            TO SCALE INTO 512X512 
         RR        E
         PUSH      HL         SAVE X COORD. 
         LD        HL,(BIAS)  BIAS Y COORD. 
         ADD       HL,DE
         RES       1,H        APPLY 512 MODULUS 
         EX        DE,HL
         POP       HL 
         RET
* 
ERR      EQU       *
         POP       AF 
         RET
**********
* GET NEXT 3 DATA BYTES AND ASSEMBLE THEM 
* INTO A 2-BIT WORD IN C REG. AND A 16-BIT WORD IN HL REG.
**********
GET3     EQU       *
         LD        A,3FH      UNBIAS CHAR 
         AND       C
         LD        C,A
 
         LD        HL,NBYTES
         LD        A,(HL) 
         INC       (HL)       INCREMENT NBYTES
         AND       A          TEST NBYTES 
         JR        NZ,GET3.1
 
         LD        L,C        FIRST CHAR
         LD        H,A
         LD        (DWORD),HL 
         POP       HL 
         RET
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
 
GET3.1   EQU       *
         DEC       A
         JR        NZ,GET3.2
 
         LD        A,C        SECOND CHAR 
         RRCA 
         RRCA 
         LD        D,A
         AND       0C0H 
         LD        E,A
         LD        A,D
         AND       0FH
         LD        D,A
         LD        HL,(DWORD) 
         ADD       HL,DE
         LD        (DWORD),HL 
         POP       HL 
         RET
 
GET3.2   EQU       *
         LD        A,C        THIRD CHAR
         RLCA 
         RLCA 
         RLCA 
         RLCA 
         LD        C,A
         AND       0F0H 
         LD        D,A
         LD        E,00H
         LD        HL,(DWORD) 
         ADD       HL,DE
         LD        A,C
         AND       03H
         LD        C,A
         XOR       A
         LD        (NBYTES),A CLEAR NBYTES
         LD        (CMODE),A  CLEAR CMODE 
         RET
         EJECT     USER MODE ENTRY
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        USER MODES 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     2
MODE5    EQU       *
         CALL      GET3       GET NEXT 3 BYTES IN C,H,L 
         EX        DE,HL      DE=BITS 16-01 (C=BITS 18-17)
         LD        A,01H      FLAG USER PROGRAM RUNNING 
         LD        (USERFLG),A
         LD        HL,(MOD5A)     LOAD MODE 5 ADDRESS 
         JP        (HL) 
* 
MODE6    EQU       *
         CALL      GET3       GET NEXT 3 BYTES IN C,H,L 
         EX        DE,HL      DE=BITS 16-01 (C=BITS 18-17)
         LD        A,01H      FLAG USER PROGRAM RUNNING 
         LD        (USERFLG),A
         LD        HL,(MOD6A)     LOAD MODE 6 ADDRESS 
         JP        (HL) 
* 
MODE7    EQU       *
         CALL      GET3       GET NEXT 3 BYTES IN C,H,L 
         EX        DE,HL      DE=BITS 16-01 (C=BITS 18-17)
         LD        A,01H      FLAG USER PROGRAM RUNNING 
         LD        (USERFLG),A
         LD        HL,(MOD7A)     LOAD MODE 7 ADDRESS 
         JP        (HL) 
         EJECT     ASSEMBLE COMM LINE INPUT 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        PROCESS INTERRUPT MASK AND ENABLE DEVICES
* 
*        INTERRUPT MASK 
*        BIT 0     I/O TIMEOUT
*        BIT 1     SHORT INTERVAL 
*        BIT 2     LONG INTERVAL
*        BIT 3     EXTERNAL DEVICE
*        BIT 4     PLATO COMM CHARACTER REQUEST 
*        BIT 5     TOUCH PANEL
*        BIT 6     KEYBOARD 
*        BIT 7     PLATO COMM CHARACTER READY 
* 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
ENAB     EQU       *
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        L,A        SAVE CURRENT ENABLE BITS
         AND       20H        MASK FOR TP ENABLE
         JR        Z,ENAB.1   IF ZERO, DISABLE TOUCH PANEL
         LD        A,(M.ENAB)  TEST FOR REENABLE OF TP
         AND       20H
         JR        NZ,ENAB.1  IF REENABLE, ENAB.1 
         IN        A,(SYSSTAT)  TEST FOR TOUCH PANEL DATA 
         BIT       4,A
         JR        Z,ENAB.1      NO DATA, ENAB.1
         IN        A,(TPDATA)    RID OF EXTRA TOUCH 
ENAB.1   EQU       *
         LD        A,L
         AND       6CH        DISABLE UNALLOWED INTERRUPTS
         OR        44H        ENABLE LONG INTERVAL AND KYBD 
         LD        (M.ENAB),A       AND STORE 
         OUT       (INTMSK),A     ENABLE/DISABLE DEVICES
         RET
         EJECT     M.CCR
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        M.CCR AND CHARACTER PLOTTING PARAMETERS ARE SET IN 
*        ACCORDANCE EITH THE CONTENTS OF HL REGISTER PAIR.
* 
*        BIT       FUNCTION 
*        0         1=VERTICAL, 0=HORIZONTAL 
*        1,2,3     CHARACTER MEMORY SELECT, 0-7 
*        4         UNUSED 
*        5         1=SIZE TWO CHARACTERS, 0=SIZE ONE CHARACTER
*        6         1=REVERSE, 0=FORWARD 
*        7         1=UNCOVER CODE LAST CHARACTER CODE RECEIVED
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
CCR      EQU       *
         LD        (M.CCR),HL  STORE BIT SETTINGS IN M.CCR
         LD        A,0EH      SET UP (MEMSEL) 
         AND       L
         CALL      LDMEMSEL 
         LD        A,(M.CCR)  SET UP (SIZE) 
         LD        HL,8 
         BIT       5,A
         JR        Z,CCR.1
         ADD       HL,HL
CCR.1    LD        (SIZE),HL
         JP        CG.SEL     SET UP (CG.ADR) 
         EJECT     CHAR. GEN. SELECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        CHARACTER GENERATOR SELECT 
* 
*        THIS ROUTINE SELECTS THE CORRECT CHARACTER GENERATOR 
*        PLOT CHARACTERS DEPENDING ON HORIZONTAL OR VERTICAL P
*        WEATHER CHARACTER STARTS ON BYTE BOUNDARY OR OFF SET,
*        AND THE WRITE/ERASE BIT SETTING. 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     2
CG.SEL   EQU       *
         LD        A,(M.MODE)     LOAD WRITE/ERASE
         AND       03               BITS FROM MODE SELECT.
         LD        C,A
         LD        A,(M.CCR)      LOAD HOR/VERT BITS
         SET       2,C
         BIT       0,A            TEST FOR HOR. OR VERT. PLOT 
         JR        NZ,CGSEL1      JUMP IF VERT PLOT 
         RES       2,C              ELSE CLEAR BIT FOR HORIZON
* 
CGSEL1   EQU       *
         LD        B,00           LOAD REGISTERS BC 
         SLA       C                FOR INDEX TO TABLE
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         LD        HL,CG.TBL      LOAD FWA OF TABLE 
         ADD       HL,BC            AND ADD INDEX 
         LD        A,(HL)         LOAD LOWER BITS OF CG ADDRES
         LD        (CG.ADR),A       AND STORE 
         INC       HL 
         LD        A,(HL)         LOAD UPPER BITS OF CG ADDRES
         LD        (CG.ADR+1),A     AND STORE 
         RET
* 
*        CHARACTER GENERATOR ADDRESS TABLE
* 
CG.TBL   EQU       *
         DEFW      HPLOTI     HORIZONTAL  PLOT INVERSE
         DEFW      HPLOTN         HORIZONTAL PLOT NORMAL
         DEFW      HPLOTOE    HORIZONTAL OVERSTRIKE ERASE 
         DEFW      HPLOTOW    HORIZONTAL OVERSTRIKE WRITE 
         DEFW      VPLOTI 
         DEFW      VPLOTN 
         DEFW      VPLOTOE
         DEFW      VPLOTOW
         EJECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        CALCULATE DELTA OF X AND Y BEGIN AND END POINTS
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
CALDELX  EQU       *
         EX        DE,HL
         LD        HL,(XEND)      LOAD X END POINT
         LD        B,08H          LOAD PLOTTING BIT 
         CALL      CALDEL         DO CALCULATION
         LD        (XDELTA),HL    STORE DELTA 
         RET
* 
CALDELY  EQU       *
         EX        DE,HL
         LD        HL,(YEND)      LOAD Y END POINT
         LD        B,10H          LOAD PLOTTING BIT 
         CALL      CALDEL         DO CALCULATION
         LD        (YDELTA),HL    STORE DELTA Y 
         RET
* 
CALDEL   EQU       *
         AND       A              CLEAR CARRY BIT 
         SBC       HL,DE          SUBTRACT BEGIN POINT FROM EN
         RET       P              RETURN IF RESULT POSITIVE 
* 
         LD        A,L
         CPL                      COMPLIMENT
         LD        L,A              NEGATIVE DELTA
         LD        A,H
         CPL
         LD        H,A
         INC       HL 
         LD        A,C
         OR        B              LOAD NEGATIVE DELTA FLAG
         LD        C,A
         RET
         EJECT     DIVIDE ROUTINE 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        DIVIDEND  HL REGISTERS 
*        DIVISOR   DE REGISTERS 
*        QUOTIENT  BC REGISTERS 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     2
DIVIDE   EQU       *
         LD        BC,0040H       SET SHIFT COUNT TO TEN PLACE
* 
DIV1     EQU       *
         ADD       HL,HL          SHIFT DIVIDEND LEFT ONE PLAC
         LD        (SAVE1),HL       AND SAVE
         SBC       HL,DE          SUBTRACT DIVISOR FROM DIVIDE
         JR        NC,DIV2
* 
         LD        HL,(SAVE1) 
* 
DIV2     EQU       *
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         CCF                      COMPLIMENT CARRY
         RL        C              SHIFT QUOTIENT
         RL        B                INTO BC REGISTERS 
         JR        NC,DIV1        REPEAT IF NOT COMPLETE
* 
         LD        L,C
         LD        H,B
         ADD       HL,HL          LEFT
         ADD       HL,HL            JUSTIFY 
         ADD       HL,HL              FRACTIONAL
         ADD       HL,HL                QUOTIENT
         ADD       HL,HL
         ADD       HL,HL
         EX        DE,HL
         LD        HL,8000H       LOAD HALF BIT OFF SET 
         RET                      EXIT TO CALLER
         EJECT     INPUT TO USER
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        INPUT FROM KEYBOARD, TOUCH PANEL OR EXTERNAL DEVICE
* 
*        DATA WORDS ARE LOADED FROM THE USER FIFO BUFFER AND T
*        TO THE USER IN REGISTERS HL. 
*        ONE DATA WORD IS TRANSFERED EACH TIME THIS ROUTINE 
*        IS CALLED. 
*        IF THE USER BUFFER IS EMPTY, THE MOST SIGNIFICANT BIT
*        OF H REGISTE  IS SET.
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     2
INPUT    EQU       *
         LD        DE,USBUF   LOAD ADDRESS OF USER BUFFER 
         LD        HL,8000H 
         LD        A,(DE)         LOAD BUFFER COUNT 
         OR        A                AND TEST FOR DATA IN BUFFE
         RET       Z              NO DATA, RETURN TO CALLER 
* 
         EX        DE,HL
         DEC       (HL)           DECREMENT COUNT 
         INC       HL             STEP ADDRESS TO 
         INC       HL               OUTPUT INDEX
         LD        A,07 
         AND       (HL)           MASK INDEX FOR EIGHT WORD BU
         INC       (HL)           INCREMENT INDEX 
* 
         INC       HL             ADVANCE ADDRESS TO START OF 
         RLCA 
         LD        E,A            LOAD INDEX TO 
         LD        D,00             DE REGISTER PAIR
         ADD       HL,DE          ADD INDEX TO START ADDRESS
         LD        E,(HL)         LOAD LOWER BITS OF WORD 
         INC       HL 
         LD        D,(HL)         LOAD UPPER BITS OF WORD 
         EX        DE,HL
         RET                      EXIT
         EJECT
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        SET STEP COORDINATE ROUTINE DIRECTION BITS 
* 
*        THIS ROUTINE SETS THE DIRECTION OF THE STEP ROUTINES.
*        THE LOWER TWO BITS OF HL REGISTERS ARE LOADED TO M.DI
*                  BIT 0          0  STEP Y FORWARD (UP)
*                                 1  STEP Y REVERSE (DOWN)
*                  BIT 1          0  STEP X FORWARD (RIGHT) 
*                                 1  STEP X REVERSE (LEFT)
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
DIR      EQU       *
         LD        (M.DIR),HL     STORE DIRECTION BITS
         RET
         EJECT     OUTPUT COORDINATES 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        SET NEW Y COORDINATE 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
OUTY     EQU       *
         LD        A,01           MASK FOR
         AND       H                NINE BIT
         LD        H,A                COORDINATE
         LD        (YREG),HL
         CALL      COMPHL 
         LD        DE,(DMAA)      LOAD DMA ADDRESS
         RES       0,D
         LD        A,H
         OR        D              LOAD UPPER BIT INTO ADDRESS 
         SET       7,A
         LD        H,A
         LD        (DMAA),HL      STORE NEW REFRESH MEMORYY AD
         INC       H              ADD TWO HUNDRED 
         INC       H                TO ADDRESS
         SET       7,H            SET REFRESH MEMORY BIT
         LD        (DMA1),HL        AND STORE 
         INC       H              ADD FOUR HUNDRED
         INC       H                TO REFRESH ADDRESS
         SET       7,H            SET REFRESH MEMORY BIT
         LD        (DMA2),HL        AND STORE 
         LD        A,L
         AND       0F0H 
         LD        L,A
         LD        A,01H
         AND       H
         OR        L
         LD        HL,BP
         JR        Z,OUTY1
         RES       7,(HL) 
         JR        INPY 
OUTY1    SET       7,(HL) 
* 
*        INPUT Y COORDINATE 
* 
INPY     EQU       *
         LD        HL,(YREG)
         RET
         EJECT     OUTPUT Y COORDINATE
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
*        SET NEW X COORDINATE 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
OUTX     EQU       *
         LD        A,01           MASK FOR
         AND       H                NINE BIT
         LD        H,A                COORDINATE
         LD        (XREG),HL  STORE NINE BIT COORDINATE 
         LD        A,07H
         AND       L
         LD        E,A
         LD        A,(BP) 
         AND       80H
         OR        E
         LD        (BP),A 
         LD        DE,(DMAA)      LOAD DMA ADDRESS
         LD        A,81H          LOAD MASK 
         AND       D              MASK SAVE BITS OF ADDRESS 
         LD        D,A
         LD        A,0F8H 
         AND       L              MASK NEW BITS 
         SRL       A
         SRL       A
         OR        D              INCLUDE Y BITS INTO ADDRESS 
         LD        D,A
         BIT       0,H            TEST UPPER BIT
         JR        Z,OUTX1
         SET       6,D            SET UPPER BIT 
OUTX1    EQU       *
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         SET       7,D
         LD        (DMAA),DE      LOAD NEW DMA ADDRESS
         INC       D              ADD TWO HUNDRED 
         INC       D                TO REFRESH ADDRESS
         SET       7,D            SET REFRESH MEMORY BIT
         LD        (DMA1),DE        AND STORE 
         INC       D              ADD FOUR HUNDRED
         INC       D                TO REFRESH ADDRESS
         SET       7,D            SET REFRESH MEMORY BIT
         LD        (DMA2),DE        AND STORE 
         SPACE     2
* 
*        INPUT X COORDINATE 
* 
INPX     EQU       *
         LD        HL,(XREG)
         RET
         EJECT     COMPLEMENT HL REGISTER PAIR
* 
COMPHL   EQU       *
         LD        A,L
         CPL
         LD        L,A
         LD        A,H
         CPL
         AND       01 
         LD        H,A
         RET
         EJECT     STEP X AND Y COORDINATES 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
* 
*        STEP X COORDINATE
* 
*        STEP THE X COORDINATE ONE DOT DEPENDING ON THE SETTIN
*        BIT 1 OF M.DIR.
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
STEPX    EQU       *
         CALL      INPX 
         LD        A,(M.DIR)
         BIT       1,A            TEST FOR DIRECTION OF STEP
         JR        NZ,STEPX1      STEP NEGATIVE IF NOT ZERO 
         SPACE     1
         INC       HL 
         JP        R.OUTX           LOAD X COORDINATE 
* 
STEPX1   EQU       *
         DEC       HL 
         JP        R.OUTX         LOAD Y COORDINATE 
         SPACE     2
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
* 
* 
*        STEP Y COORDINATE
* 
*        STEP THE Y COORDINATE ONE DOT DEPENDING ON THE SETTIN
*        OF BIT 0 OF M.DIR. 
* 
*  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  * 
         SPACE     1
STEPY    EQU       *
         CALL      INPY 
         LD        A,(M.DIR)      LOAD STEP DIRECTION FLAG
         BIT       0,A            TEST DIRECTION OF STEP
         JR        NZ,STEPY1      GO NEGATIVE IF NOT ZERO 
         SPACE     1
         INC       HL 
         JP        R.OUTY         LOAD Y COORDINATE 
         SPACE     1
         SPACE     1
STEPY1   EQU       *
         DEC       HL 
         JP        R.OUTY         LOAD Y COORDINATE 
         EJECT     MASK GENERATOR 
         EJECT
* 
*        MASK GENERATOR 
* 
*        ENTRY
*                  B = LOOP COUNT, (LOWER THREE BITS OF Y COOR
* 
*        EXIT 
*                  D = 11100000 
*                  E = 00011111 
*                  H = 11011111 
*                  L = 00100000 
* 
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
MASKS    EQU       *
         LD        A,(BP)         LOAD LOWER THREE BITS OF Y
         AND       07H
* 
MASKS0   EQU       *
         LD        B,A
         OR        A              TEST BITS FOR ZERO
         LD        A,0FFH         LOAD A ALL ONES 
         LD        L,01H
         JR        Z,MASKS2       NO SHIFT IF ZERO
* 
MASKS1   EQU       *
         SLA       A          SHIFT LEFT ZERO FILLING 
         SLA       L
         DJNZ      MASKS1         STAY IN LOOP FOR BP COUNT 
* 
MASKS2   EQU       *
         LD        D,A            LOAD 11110000 
         CPL
         LD        E,A            LOAD 00001111 
         LD        A,L
         CPL
         LD        H,A            LOAD 11101111 
         RET
         EJECT     CHARACTER CONVERT ROUTINE
         SPACE     2
* CONVERT CHARACTER DATA TO ACCOMMODATE DISPLAY CHANGE
* ENTRY  HL        NUMBER CHARACTERS TO CONVERT 
*        DE        FWA OF CHARACTER DATA
         SPACE     2
CONVERT  EQU       *
         LD        A,L        STORE NUMBER OF CHARS 
         LD        (NCHARS),A     TO CONVERT
CON0     EQU       *
         PUSH      DE         CHARACTER DATA SOURCE ADDR
         LD        C,E          ON STACK AND BC 
         LD        B,D
         LD        HL,SAVE1+8 TEMP DEST. ADDR OF ODD ROWS 
         EXX                  BRING IN AUX. REGS. 
         POP       DE         CHARACTER DATA SOURCE ADDR
         INC       DE         POINTS TO EVEN ROWS 
         LD        BC,0808H   B';BIT COUNT; C';LOOP COUNT 
         LD        HL,SAVE1   TEMP DESTIN. ADDR OF EVEN ROWS
CON1     EQU       *
         LD        A,(DE)     ROTATE UPPER BIT OF EVEN ROWS 
         RLA                  TO LOWER BIT OF DESTINATION 
         LD        (DE),A     SAVE ROTATED DATA OF SOURCE 
         RR        (HL) 
         INC       DE         POINT TO NEXT EVEN ROW OF DATA
         INC       DE 
         EXX                  BRING IN MAIN REGS. 
         LD        A,(DE)     ROTATE UPPER BIT OF ODD ROWS
         RLA                  TO LOWER BIT OF DESTINATION 
         LD        (DE),A     SAVE ROTATED DATA OF SOURCE 
         RR        (HL) 
         INC       DE         POINT TO NEXT ODD ROW DATA
         INC       DE 
         EXX                  BRING IN AUX. REGS. 
         DJNZ      CON1       DECREMENT BIT COUNT TO 0
         EXX                  BRING IN MAIN REGS. 
         INC       HL         POINT TO NEXT DEST. WORD
*                                FOR ODD ROWS 
         LD        E,C        DE GETS SOURCE FWA AGAIN
         LD        D,B
         PUSH      DE 
         EXX                  BRING IN AUX. REGS. 
         POP       DE         DE GETS SOURCE FWA+1 FOR
         INC       DE            EVEN ROWS
         INC       HL         POINT TO NEXT DEST. WORD
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
*                                FOR EVEN ROWS
         LD        B,08       RESET BIT COUNT 
         DEC       C          DECREMENT LOOP COUNT TO 0 
         JR        NZ,CON1
         EXX                  BRING IN MAIN REGS. 
         LD        E,C        DE GETS SOURCE FWA
         LD        D,B
         LD        HL,SAVE1   HL GETS TEMPORARY FWA 
         LD        BC,0010H   BC GETS 16 BYTE COUNT 
         LDIR                 CONVERTED DATA TO SOURCE
         LD        A,(NCHARS) MORE DATA TO CONVERT'/
         DEC       A
         LD        (NCHARS),A RESTORE NUMBER OF CHARACTERS
         JR        NZ,CON0    NO, DO NEXT CHARACTER 
         RET                  RETURN TO CALLER
         SPACE     4
**********
* BULK ERASE THE SCREEN 
**********
BULKER   EQU       *
         LD        A,06H      DO BULK ERASE 
         OUT       (VIDEOCTL),A 
BULKER1  IN        A,(SYSSTAT) GET SYSTEM STATUS
         RLCA 
         JR        C,BULKER1  WAIT UNTIL BULK ERASE DONE
         RET
         EJECT
****************************************
*        M0 CHARACTER SET              *
****************************************
M0CODE00 EQU       *          SPACE 
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,00,00,00
M0CODE01 EQU       *          EXCLAMATION MARK
         HEX       00,00,00,08
         HEX       08,08,08,08
         HEX       08,00,00,08
         HEX       00,00,00,00
M0CODE02 EQU       *          DOUBLE QUOTATION MARK 
         HEX       00,00,00,14
         HEX       14,14,00,00
         HEX       00,00,00,00
         HEX       00,00,00,00
M0CODE03 EQU       *          NUMBER SIGN 
         HEX       00,00,00,14
         HEX       14,7F,14,7F
         HEX       14,14,00,00
         HEX       00,00,00,00
M0CODE04 EQU       *          DOLLAR SIGN 
         HEX       00,00,00,08
         HEX       3E,49,09,3E
         HEX       48,49,3E,08
         HEX       00,00,00,00
M0CODE05 EQU       *          PERCENT SIGN
         HEX       00,00,00,02
         HEX       45,25,12,08
         HEX       24,52,51,20
         HEX       00,00,00,00
M0CODE06 EQU       *          AMPERSAND 
         HEX       00,00,00,04
         HEX       0A,0A,04,46
         HEX       49,31,31,4E
         HEX       00,00,00,00
M0CODE07 EQU       *          APOSTROPHE
         HEX       00,00,00,08
         HEX       08,08,00,00
         HEX       00,00,00,00
         HEX       00,00,00,00
M0CODE08 EQU       *          LEFT PARENTHESIS
         HEX       00,00,00,40
         HEX       20,10,10,10
         HEX       10,10,10,20
         HEX       40,00,00,00
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
M0CODE09 EQU       *          RIGHT PARENTHESIS 
         HEX       00,00,00,01
         HEX       02,04,04,04
         HEX       04,04,04,02
         HEX       01,00,00,00
M0CODE0A EQU       *          ASTERISK
         HEX       00,00,00,00
         HEX       00,08,2A,14
         HEX       14,2A,08,00
         HEX       00,00,00,00
M0CODE0B EQU       *          PLUS SIGN 
         HEX       00,00,00,00
         HEX       00,00,08,08
         HEX       3E,08,08,00
         HEX       00,00,00,00
M0CODE0C EQU       *          COMMA 
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,00,0C,0C
         HEX       08,04,00,00
M0CODE0D EQU       *          MINUS SIGN
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       3E,00,00,00
         HEX       00,00,00,00
M0CODE0E EQU       *          PERIOD
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,00,0C,0C
         HEX       00,00,00,00
M0CODE0F EQU       *          SLASH 
         HEX       00,00,00,00
         HEX       00,40,20,10
         HEX       08,04,02,01
         HEX       00,00,00,00
M0CODE10 EQU       *          ZERO
         HEX       00,00,00,00
         HEX       5C,22,32,2A
         HEX       2A,26,22,1D
         HEX       00,00,00,00
M0CODE11 EQU       *          ONE 
         HEX       00,00,00,00
         HEX       08,0C,08,08
         HEX       08,08,08,1C
         HEX       00,00,00,00
M0CODE12 EQU       *          TWO 
         HEX       00,00,00,00
         HEX       1C,22,20,10
         HEX       08,04,02,3E
         HEX       00,00,00,00
M0CODE13 EQU       *          THREE 
         HEX       00,00,00,00
         HEX       1C,22,20,18
         HEX       20,20,22,1C
         HEX       00,00,00,00
M0CODE14 EQU       *          FOUR
         HEX       00,00,00,00
         HEX       20,30,28,24
         HEX       7E,20,20,20
         HEX       00,00,00,00
M0CODE15 EQU       *          FIVE
         HEX       00,00,00,00
         HEX       3E,02,02,1E
         HEX       20,20,10,0E
         HEX       00,00,00,00
M0CODE16 EQU       *          SIX 
         HEX       00,00,00,00
         HEX       18,04,02,1E
         HEX       22,22,22,1C
         HEX       00,00,00,00
M0CODE17 EQU       *          SEVEN 
         HEX       00,00,00,00
         HEX       3E,20,10,10
         HEX       08,08,04,04
         HEX       00,00,00,00
M0CODE18 EQU       *          EIGHT 
         HEX       00,00,00,00
         HEX       1C,22,22,1C
         HEX       22,22,22,1C
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         HEX       00,00,00,00
M0CODE19 EQU       *          NINE
         HEX       00,00,00,00
         HEX       1C,22,22,22
         HEX       3C,20,10,0C
         HEX       00,00,00,00
M0CODE1A EQU       *          COLON 
         HEX       00,00,00,00
         HEX       00,00,0C,0C
         HEX       00,00,0C,0C
         HEX       00,00,00,00
M0CODE1B EQU       *          SEMICOLON 
         HEX       00,00,00,00
         HEX       00,00,0C,0C
         HEX       00,00,0C,0C
         HEX       08,04,00,00
M0CODE1C EQU       *          LESS THAN SIGN
         HEX       00,00,00,00
         HEX       00,10,08,04
         HEX       02,04,08,10
         HEX       00,00,00,00
M0CODE1D EQU       *          EQUAL SIGN
         HEX       00,00,00,00
         HEX       00,00,00,3E
         HEX       00,3E,00,00
         HEX       00,00,00,00
M0CODE1E EQU       *          GREATER THAN SIGN 
         HEX       00,00,00,00
         HEX       00,04,08,10
         HEX       20,10,08,04
         HEX       00,00,00,00
M0CODE1F EQU       *          QUESTION MARK 
         HEX       00,00,00,1C
         HEX       22,22,20,10
         HEX       08,08,00,08
         HEX       00,00,00,00
M0CODE20 EQU       *          COMMERCIAL AT SIGN
         HEX       00,00,00,00
         HEX       00,1C,22,59
         HEX       55,55,39,02
         HEX       1C,00,00,00
M0CODE21 EQU       *          UPPER CASE A
         HEX       00,00,00,1C
         HEX       22,41,41,7F
         HEX       41,41,41,41
         HEX       00,00,00,00
M0CODE22 EQU       *          UPPER CASE B
         HEX       00,00,00,1F
         HEX       21,21,3F,41
         HEX       41,41,41,3F
         HEX       00,00,00,00
M0CODE23 EQU       *          UPPER CASE C
         HEX       00,00,00,3C
         HEX       42,01,01,01
         HEX       01,01,42,3C
         HEX       00,00,00,00
M0CODE24 EQU       *          UPPER CASE D
         HEX       00,00,00,1F
         HEX       21,41,41,41
         HEX       41,41,21,1F
         HEX       00,00,00,00
M0CODE25 EQU       *          UPPER CASE E
         HEX       00,00,00,7F
         HEX       01,01,01,1F
         HEX       01,01,01,7F
         HEX       00,00,00,00
M0CODE26 EQU       *          UPPER CASE F
         HEX       00,00,00,7F
         HEX       01,01,01,0F
         HEX       01,01,01,01
         HEX       00,00,00,00
M0CODE27 EQU       *          UPPER CASE G
         HEX       00,00,00,3C
         HEX       42,01,01,01
         HEX       71,41,42,3C
         HEX       00,00,00,00
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
M0CODE28 EQU       *          UPPER CASE H
         HEX       00,00,00,41
         HEX       41,41,41,7F
         HEX       41,41,41,41
         HEX       00,00,00,00
M0CODE29 EQU       *          UPPER CASE I
         HEX       00,00,00,3E
         HEX       08,08,08,08
         HEX       08,08,08,3E
         HEX       00,00,00,00
M0CODE2A EQU       *          UPPER CASE J
         HEX       00,00,00,7C
         HEX       10,10,10,10
         HEX       10,10,11,0E
         HEX       00,00,00,00
M0CODE2B EQU       *          UPPER CASE K
         HEX       00,00,00,41
         HEX       21,11,09,05
         HEX       0B,11,21,41
         HEX       00,00,00,00
M0CODE2C EQU       *          UPPER CASE L
         HEX       00,00,00,01
         HEX       01,01,01,01
         HEX       01,01,01,7F
         HEX       00,00,00,00
M0CODE2D EQU       *          UPPER CASE M
         HEX       00,00,00,41
         HEX       63,55,49,41
         HEX       41,41,41,41
         HEX       00,00,00,00
M0CODE2E EQU       *          UPPER CASE N
         HEX       00,00,00,41
         HEX       43,45,45,49
         HEX       51,51,61,41
         HEX       00,00,00,00
M0CODE2F EQU       *          UPPER CASE O
         HEX       00,00,00,1C
         HEX       22,41,41,41
         HEX       41,41,22,1C
         HEX       00,00,00,00
M0CODE30 EQU       *          UPPER CASE P
         HEX       00,00,00,3F
         HEX       41,41,41,3F
         HEX       01,01,01,01
         HEX       00,00,00,00
M0CODE31 EQU       *          UPPER CASE Q
         HEX       00,00,00,1C
         HEX       22,41,41,41
         HEX       41,41,22,1C
         HEX       08,30,00,00
M0CODE32 EQU       *          UPPER CASE R
         HEX       00,00,00,3F
         HEX       41,41,41,3F
         HEX       09,11,21,41
         HEX       00,00,00,00
M0CODE33 EQU       *          UPPER CASE S
         HEX       00,00,00,3E
         HEX       41,01,01,3E
         HEX       40,40,41,3E
         HEX       00,00,00,00
M0CODE34 EQU       *          UPPER CASE T
         HEX       00,00,00,7F
         HEX       08,08,08,08
         HEX       08,08,08,08
         HEX       00,00,00,00
M0CODE35 EQU       *          UPPER CASE U
         HEX       00,00,00,41
         HEX       41,41,41,41
         HEX       41,41,41,3E
         HEX       00,00,00,00
M0CODE36 EQU       *          UPPER CASE V
         HEX       00,00,00,41
         HEX       41,22,22,22
         HEX       14,14,08,08
         HEX       00,00,00,00
M0CODE37 EQU       *          UPPER CASE W
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         HEX       00,00,00,41
         HEX       41,41,49,49
         HEX       49,49,55,22
         HEX       00,00,00,00
M0CODE38 EQU       *          UPPER CASE X
         HEX       00,00,00,41
         HEX       41,22,14,08
         HEX       14,22,41,41
         HEX       00,00,00,00
M0CODE39 EQU       *          UPPER CASE Y
         HEX       00,00,00,41
         HEX       41,22,14,08
         HEX       08,08,08,08
         HEX       00,00,00,00
M0CODE3A EQU       *          UPPER CASE Z
         HEX       00,00,00,7F
         HEX       41,20,10,08
         HEX       04,02,41,7F
         HEX       00,00,00,00
M0CODE3B EQU       *          LEFT BRACKET
         HEX       00,00,00,70
         HEX       10,10,10,10
         HEX       10,10,10,10
         HEX       70,00,00,00
M0CODE3C EQU       *          REVERSE SLASH 
         HEX       00,00,00,00
         HEX       00,01,02,04
         HEX       08,10,20,40
         HEX       00,00,00,00
M0CODE3D EQU       *          RIGHT BRACKET 
         HEX       00,00,00,07
         HEX       04,04,04,04
         HEX       04,04,04,04
         HEX       07,00,00,00
M0CODE3E EQU       *          HAT (CIRCUMFLEX)
         HEX       00,08,14,22
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,00,00,00
M0CODE3F EQU       *          UNDERLINE 
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,7F,00,00
M0CODE40 EQU       *          LEFT ACCENT MARK
         HEX       00,02,04,08
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,00,00,00
M0CODE41 EQU       *          LOWER CASE A
         HEX       00,00,00,00
         HEX       00,00,1E,20
         HEX       3E,21,21,5E
         HEX       00,00,00,00
M0CODE42 EQU       *          LOWER CASE B
         HEX       00,00,00,01
         HEX       01,01,1D,23
         HEX       41,41,23,1D
         HEX       00,00,00,00
M0CODE43 EQU       *          LOWER CASE C
         HEX       00,00,00,00
         HEX       00,00,3C,42
         HEX       01,01,42,3C
         HEX       00,00,00,00
M0CODE44 EQU       *          LOWER CASE D
         HEX       00,00,00,40
         HEX       40,40,5C,62
         HEX       41,41,62,5C
         HEX       00,00,00,00
M0CODE45 EQU       *          LOWER CASE E
         HEX       00,00,00,00
         HEX       00,00,3C,42
         HEX       7F,01,02,7C
         HEX       00,00,00,00
M0CODE46 EQU       *          LOWER CASE F
         HEX       00,00,00,30
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         HEX       48,08,1C,08
         HEX       08,08,08,1C
         HEX       00,00,00,00
M0CODE47 EQU       *          LOWER CASE G
         HEX       00,00,00,00
         HEX       00,00,5E,21
         HEX       21,1E,01,3E
         HEX       41,3E,00,00
M0CODE48 EQU       *          LOWER CASE H
         HEX       00,00,00,03
         HEX       02,02,3A,46
         HEX       42,42,42,42
         HEX       00,00,00,00
M0CODE49 EQU       *          LOWER CASE I
         HEX       00,00,00,08
         HEX       00,00,0C,08
         HEX       08,08,08,1C
         HEX       00,00,00,00
M0CODE4A EQU       *          LOWER CASE J
         HEX       00,00,00,08
         HEX       00,00,0C,08
         HEX       08,08,08,08
         HEX       08,08,06,00
M0CODE4B EQU       *          LOWER CASE K
         HEX       00,00,00,03
         HEX       02,02,32,0A
         HEX       06,0A,12,63
         HEX       00,00,00,00
M0CODE4C EQU       *          LOWER CASE L
         HEX       00,00,00,0C
         HEX       08,08,08,08
         HEX       08,08,08,1C
         HEX       00,00,00,00
M0CODE4D EQU       *          LOWER CASE M
         HEX       00,00,00,00
         HEX       00,00,37,49
         HEX       49,49,49,49
         HEX       00,00,00,00
M0CODE4E EQU       *          LOWER CASE N
         HEX       00,00,00,00
         HEX       00,00,3B,46
         HEX       42,42,42,42
         HEX       00,00,00,00
M0CODE4F EQU       *          LOWER CASE O
         HEX       00,00,00,00
         HEX       00,00,1C,22
         HEX       41,41,22,1C
         HEX       00,00,00,00
M0CODE50 EQU       *          LOWER CASE P
         HEX       00,00,00,00
         HEX       00,00,1D,23
         HEX       41,41,23,1D
         HEX       01,01,01,00
M0CODE51 EQU       *          LOWER CASE Q
         HEX       00,00,00,00
         HEX       00,00,5C,62
         HEX       41,41,62,5C
         HEX       40,40,40,00
M0CODE52 EQU       *          LOWER CASE R
         HEX       00,00,00,00
         HEX       00,00,3B,46
         HEX       02,02,02,02
         HEX       00,00,00,00
M0CODE53 EQU       *          LOWER CASE S
         HEX       00,00,00,00
         HEX       00,00,3E,01
         HEX       3E,40,41,3E
         HEX       00,00,00,00
M0CODE54 EQU       *          LOWER CASE T
         HEX       00,00,00,04
         HEX       04,04,3F,04
         HEX       04,04,04,38
         HEX       00,00,00,00
M0CODE55 EQU       *          LOWER CASE U
         HEX       00,00,00,00
         HEX       00,00,21,21
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         HEX       21,21,21,5E
         HEX       00,00,00,00
M0CODE56 EQU       *          LOWER CASE V
         HEX       00,00,00,00
         HEX       00,00,63,22
         HEX       14,14,08,08
         HEX       00,00,00,00
M0CODE57 EQU       *          LOWER CASE W
         HEX       00,00,00,00
         HEX       00,00,41,49
         HEX       49,49,55,22
         HEX       00,00,00,00
M0CODE58 EQU       *          LOWER CASE X
         HEX       00,00,00,00
         HEX       00,00,43,24
         HEX       18,18,24,42
         HEX       00,00,00,00
M0CODE59 EQU       *          LOWER CASE Y
         HEX       00,00,00,00
         HEX       00,00,41,41
         HEX       41,22,14,08
         HEX       04,02,01,00
M0CODE5A EQU       *          LOWER CASE Z
         HEX       00,00,00,00
         HEX       00,00,3F,11
         HEX       08,04,22,3F
         HEX       00,00,00,00
M0CODE5B EQU       *          LEFT BRACE
         HEX       00,00,00,60
         HEX       10,10,10,10
         HEX       08,10,10,10
         HEX       10,60,00,00
M0CODE5C EQU       *          DOUBLE VERTICAL BAR 
         HEX       00,00,00,1C
         HEX       1C,1C,1C,00
         HEX       1C,1C,1C,1C
         HEX       00,00,00,00
M0CODE5D EQU       *          RIGHT BRACE 
         HEX       00,00,00,03
         HEX       04,04,04,04
         HEX       08,04,04,04
         HEX       04,03,00,00
M0CODE5E EQU       *          APPROXIMATION SIGN
         HEX       00,00,00,00
         HEX       00,00,00,4C
         HEX       32,00,00,00
         HEX       00,00,00,00
M0CODE5F EQU       *          RUBOUT
         HEX       00,00,00,3E
         HEX       3E,3E,3E,3E
         HEX       3E,3E,00,00
         HEX       00,00,00,00
M0CODE60 EQU       *          UNDERLINE CURSOR
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,00,00,FF
M0CODE61 EQU       *          CROSSHAIR CURSOR
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,00,00,04
         HEX       04,1F,04,04
M1CODE00 EQU       *          SPACE 
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,00,00,00
M1CODE01 EQU       *          SHORTER SLASH 
         HEX       00,00,00,00
         HEX       00,40,20,10
         HEX       08,04,02,01
         HEX       00,00,00,00
M1CODE02 EQU       *          EQUIVALENCE SIGN
         HEX       00,00,00,00
         HEX       00,00,3E,00
         HEX       3E,00,3E,00
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
         HEX       00,00,00,00
M1CODE03 EQU       *          TILDE 
         HEX       00,00,4C,32
         HEX       00,00,00,00
         HEX       00,00,00,00
         HEX       00,00,00,00
M1CODE04 EQU       *          ASSIGNMENT ARROW
         HEX       00,00,00,00
         HEX       00,08,0C,7A
         HEX       01,7A,0C,08
         HEX       00,00,00,00
M1CODE05 EQU       *          NOT EQUAL SIGN
         HEX       00,00,00,00
         HEX       00,40,20,7F
         HEX       08,7F,02,01
         HEX       00,00,00,00
M1CODE06 EQU       *          UP ARROW
         HEX       00,00,00,00
         HEX       00,08,1C,3E
         HEX       08,08,08,08
         HEX       00,00,00,00
M1CODE07 EQU       *          RIGHT ARROW 
         HEX       00,00,00,00
         HEX       00,00,10,30
         HEX       7F,30,10,00
         HEX       00,00,00,00
M1CODE08 EQU       *          DOWN ARROW
         HEX       00,00,00,00
         HEX       00,08,08,08
         HEX       08,3E,1C,08
         HEX       00,00,00,00
M1CODE09 EQU       *          LEFT ARROW
         HEX       00,00,00,00
         HEX       00,00,04,06
         HEX       7F,06,04,00
         HEX       00,00,00,00
M1CODE0A EQU       *          MULTIPLY SIGN 
         HEX       00,00,00,00
         HEX       00,00,24,18
         HEX       18,24,00,00
         HEX       00,00,00,00
M1CODE0B EQU       *          UPPER CASE SIGMA
         HEX       00,00,00,7F
         HEX       02,04,08,10
         HEX       08,04,02,7F
         HEX       00,00,00,00
M1CODE0C EQU       *          UPPER CASE DELTA
         HEX       00,00,00,00
         HEX       08,08,14,14
         HEX       22,22,41,7F
         HEX       00,00,00,00
M1CODE0D EQU       *          LOGICAL UNION 
         HEX       00,00,00,00
         HEX       00,00,22,22
         HEX       22,1C,00,00
         HEX       00,00,00,00
M1CODE0E EQU       *          LOGICAL INTERSECTION
         HEX       00,00,00,00
         HEX       00,00,1C,22
         HEX       22,22,00,00
         HEX       00,00,00,00
M1CODE0F EQU       *          DIVIDE SIGN 
         HEX       00,00,00,00
         HEX       00,00,08,00
         HEX       3E,00,08,00
         HEX       00,00,00,00
M1CODE10 EQU       *          LOWER CASE ALPHA
         HEX       00,00,00,00
         HEX       00,00,46,49
         HEX       29,11,19,66
         HEX       00,00,00,00
M1CODE11 EQU       *          LOWER CASE BETA 
         HEX       00,00,00,00
         HEX       18,24,22,1E
         HEX       22,42,42,3E
         HEX       02,02,01,00
* /---   BLOCK      AIST3      00 000   73/00/00  00.00 
M1CODE12 EQU       *          LOWER CASE DELTA
         HEX       00,00,00,0C
         HEX       12,22,04,0C
         HEX       12,22,22,1C
         HEX       00,00,00,00
M1CODE13 EQU       *          LOWER CASE LAMBDA 
         HEX       00,00,00,02
         HEX       04,04,08,08
         HEX       14,14,22,22
         HEX       00,00,00,00
M1CODE14 EQU       *          LOWER CASE MU 
         HEX       00,00,00,00
         HEX       00,00,24,24
         HEX       24,24,24,5C
         HEX       04,04,03,00
M1CODE15 EQU       *          LOWER CASE PI 
         HEX       00,00,00,00
         HEX       00,40,3E,15
         HEX       14,14,14,14
         HEX       00,00,00,00
M1CODE16 EQU       *          LOWER CASE RHO
         HEX       00,00,00,00
         HEX       00,00,30,48
         HEX       44,44,26,1A
         HEX       02,01,01,00
M1CODE17 EQU       *          LOWER CASE SIGMA
         HEX       00,00,00,00
         HEX       00,00,7C,0A
         HEX       11,11,11,0E
         HEX       00,00,00,00
M1CODE18 EQU       *          LOWER CASE OMEGA
         HEX       00,00,00,00
         HEX       00,00,22,41
         HEX       49,49,49,36
         HEX       00,00,00,00
M1CODE19 EQU       *          LESS THAN OR EQUAL TO 
         HEX       00,00,00,00
         HEX       30,0C,03,0C
         HEX       30,00,3F,00
         HEX       00,00,00,00
M1CODE1A EQU       *          GREATER THAN OR EQUAL TO
         HEX       00,00,00,00
         HEX       06,18,60,18
         HEX       06,00,7E,00
         HEX       00,00,00,00
M1CODE1B EQU       *          THETA 
         HEX       00,00,00,1C
         HEX       22,41,41,7F
         HEX       41,41,22,1C
         HEX       00,00,00,00
M1CODE1C EQU       *          EMBEDDED LEFT PAREN 
         HEX       00,00,00,40
         HEX       20,10,18,14
         HEX       12,14,18,30