0000-                105                      .FI
0000-             S  106                      .DO     VDU=41
0000-             S  107                                      ; Building 6809 Monitor for Flex and Teletext VDU alternative configuration
0000-             S  108                              .TF     Flex41.bin,BIN
0000-                110                      .FI
0000-             S  111                      .DO     VDU=80
0000-             S  112                                      ; Building 6809 Monitor for Flex memory and 80-Column VDU
0000-             S  113                              .TF     Flex80.bin,BIN
0000-                115                      .FI
0000-                116              .FI
0000-                117      ;
0000-                118      ; ********************************************************
0000-                119      ;
F800-                120      MPROM   .EQ     $F800                   ; Normal monitor position at top of memory
00E3-                121      MONDP   .EQ     BASE+$0300/256          ; Direct page for monitor
0000-                122      ;
0000-                123      ; VDU Configuration
0019-                124      ROWS    .EQ     25                      ; Number of rows on display.
0028-                125      COLS    .EQ     VDU&$F8                 ; Number of characters per row, 40 or 80
0400-                126      PSIZE   .EQ     VDU&$F8/10*256          ; Size of display memory in total, $0400 (1K) or $0800 (2K)
000C-                127      PAGHI   .EQ     12                      ; Page address register, high byte
000E-                128      CURHI   .EQ     14                      ; Cursor address register, high byte
0000-                129      ;
0000-                130              .DO     VDU&$F8=40              ; Location of memory that 40-Column (Teletext) VDU uses:
E400-                131      VPAGE   .EQ     BASE+$400               ;       Standard $0400
0000-                132                                              ;       Flex $E400
0000-                133                                              ; Location of CRT controller on 40-column VDU card:
E800-                134      CRTC    .EQ     BASE+$0800              ;       Standard $0800
0000-                135              .FI                             ;       Flex $E800
0000-                136      ;
0000-             S  137              .DO     VDU=80                  ; Location of memory that 80-Column VDU uses:
0000-             S  138      VPAGE   .EQ     BASE+$1000              ;       Standard $1000
0000-             S  139                                              ;       Flex $F000
0000-             S  140                                              ; Location of CRT controller on 80-column VDU card:
0000-             S  141      CRTC    .EQ     BASE+$1840              ;       Standard $1840
0000-                142              .FI                             ;       Flex $E840
0000-                143      ;
0003-                144      WRPMSK  .EQ     PSIZE/256-1             ; Mask to wrap address within PSIZE, 3 (40-column) or 7 (80-column)
0000-                145      ;
0040-                146      DRIVE   .EQ     $40                     ; Drive to bootstrap from, other drive is $80
EA00-                147      FLOPY   .EQ     BASE+$0A00              ; Location of floppy disc controller:
0000-                148                                              ;       Standard $0A00
0000-                149                                              ;       Flex $EA00
EA00-                150      FDCC    .EQ     FLOPY+0                 ; Command register
EA00-                151      FDCS    .EQ     FDCC                    ; Status register
EA01-                152      FDCP    .EQ     FLOPY+1                 ; Parameter register
EA01-                153      FDCR    .EQ     FDCP                    ; Result register
EA02-                154      FDRST   .EQ     FLOPY+2                 ; Reset register
EA04-                155      FDCD    .EQ     FLOPY+4                 ; Data register
0000-                156      ;
E980-                157      KVIA    .EQ     BASE+$0980              ; Location of Versatile Interface Adaptor
E980-                158      KORB    .EQ     KVIA+$0                 ; Output register B
E980-                159      KIRB    .EQ     KORB                    ; Input register B
E981-                160      KORA    .EQ     KVIA+$1                 ; Output register A
E981-                161      KIRA    .EQ     KORA                    ; Input register A
E982-                162      KDDRB   .EQ     KVIA+$2                 ; Data direction register B
E983-                163      KDDRA   .EQ     KVIA+$3                 ; Data direction register A
E984-                164      KT1CL   .EQ     KVIA+$4                 ; Timer 1 counter low
E985-                165      KT1CH   .EQ     KVIA+$5                 ; Timer 1 counter high
E986-                166      KT1LL   .EQ     KVIA+$6                 ; Timer 1 latch low
E987-                167      KT1LH   .EQ     KVIA+$7                 ; Timer 1 latch high
E988-                168      KT2CL   .EQ     KVIA+$8                 ; Timer 2 counter low
E989-                169      KT2CH   .EQ     KVIA+$9                 ; Timer 2 counter high
E98A-                170      KSR     .EQ     KVIA+$A                 ; Shift register
E98B-                171      KACR    .EQ     KVIA+$B                 ; Auxiliary control register
E98C-                172      KPCR    .EQ     KVIA+$C                 ; Peripheral control register
E98D-                173      KIFR    .EQ     KVIA+$D                 ; Interrupt flag register
E98E-                174      KIER    .EQ     KVIA+$E                 ; Interrupt enable register
E98F-                175      KORA2   .EQ     KVIA+$F                 ; Input/output register A without hand shake
0000-                176      ;
0F00-                177      INTDEL  .EQ     15*256                  ; Delay for single instruction trace is 15 cycles
0040-                178      T1IFLG  .EQ     %01000000               ; Interrupt flag position for timer 1
0010-                179      CB1FLG  .EQ     %00010000               ; Interrupt flag position for keyboard strobe on CB1
0000-                180      ;
00EF-                181      IKPCR   .EQ     %11101111               ; Initial value for peripheral control register,
0000-                182                                              ;       bit 0           CA1 control from printer, positive edge interrupt,
0000-                183                                              ;                           but not used in this monitor
0000-                184                                              ;       bits 1-3        CA2 control to strobe printer, normally high
0000-                185                                              ;       bit 4           CB1 control, negative edge keyboard interrupt
0000-                186                                              ;       bits 5-7        CB2 control, cassette output initially set high
0000-                187      ;
00D0-                188      IKIER   .EQ     %11010000               ; Interrupt enable register control
0000-                189                                              ;       bit 4           CB1 keyboard interrupt enable
0000-                190                                              ;       bit 6           timer 1 interrupt enable
0000-                191                                              ;       bit 7           set interrupts enabled
0000-                192                                              ;       other enables not altered
0000-                193      ;
0002-                194      PSTRB   .EQ     %00000010               ; bit position in PCR of printer strobe, to toggle CA2
0020-                195      COPBIT  .EQ     %00100000               ; bit position in PCR of cassette output, to toggle CB2
0000-                196      ;
003F-                197      SWIOP   .EQ     $3F                     ; Software interrupt used for breakpoints
0000-                198      ;
0052-                199      BUFLEN  .EQ     81+1                    ; Buffer up to 80 characters from keyboard
0000-                200      ;
002A-                201      PROMPT  .EQ     '*'                     ; Monitor prompt
007F-                202      RUBCH   .EQ     $7F                     ; Keyboard code that does rubout operation
007F-                203      BSPACE  .EQ     $7F                     ; Code that backspaces VDU, also used to do rubout
000A-                204      LF      .EQ     $0A                     ; Linefeed
000D-                205      CR      .EQ     $0D                     ; Carriage return
0020-                206      SPACE   .EQ     $20                     ; Blank space
002C-                207      COMMA   .EQ     ','                     ; The comma symbol
002D-                208      MINUS   .EQ     '-'                     ; The minus symbol
000C-                209      FFEED   .EQ     $0C                     ; Code used as clear screen command
003B-                210      SEMIC   .EQ     ';'                     ; The semicolon symbol
0000-                211      ;
0010-                212      IRQ     .EQ     $10
0004-                213      ZERO    .EQ     $04
0000-                214      ;
0000-                215      ;       Definitions of variables in page 03 / E3
0000-                216      ;       ----------------------------------------
0000-                217      ;
E35B-                218      ISTACK  .EQ     BASE+$035B              ; Stack pointer starts here
E35B-                219      RTAB1   .EQ     BASE+$035B              ; RAM table 1 starts here
0000-                220      ;
0000-                221      ;       This table is copied from ROM on start-up
0000-                222      ;
E35B-                223      STACK   .EQ     BASE+$035B              ; Position of stack pointer when empty
E35D-                224      NTRACE  .EQ     BASE+$035D              ; Number of instructions to trace before stopping
E35F-                225      BSECHO  .EQ     BASE+$035F              ; Character sent to backspace display
E360-                226      ECHOF   .EQ     BASE+$0360              ; Keyboard buffer/echo control
0000-                227                                              ;       bits 0-5        don't care
0000-                228                                              ;       bit 6           echo console input to console output if set
0000-                229                                              ;       bit 7           buffer input lines, allow rubout if set
0000-                230      ;
E361-                231      PFLAG   .EQ     BASE+$0361              ; Printer control flag, echo console output to printer if nonzero
E362-                232      PNEW    .EQ     BASE+$0362              ; This character not sent to printer
E363-                233      DELCNT  .EQ     BASE+$0363              ; Non-zero delay count for cassette, controls baud rate
E365-                234      COPADR  .EQ     BASE+$0365              ; Address for console output
E367-                235      CINADR  .EQ     BASE+$0367              ; Address for console input
E369-                236      CASOPA  .EQ     BASE+$0369              ; Address for cassette output
E36B-                237      CASINA  .EQ     BASE+$036B              ; Address for cassette input
E36D-                238      PRINT1  .EQ     BASE+$036D              ; Address of printer output routine
E36F-                239      FUNCTI  .EQ     BASE+$036F              ; Address of VDU function table
E371-                240      CMNDI   .EQ     BASE+$0371              ; Address of monitor command table
E373-                241      IRQRTS  .EQ     BASE+$0373              ; Address to go to on timer 1 interrupt
E375-                242      LINEPT  .EQ     BASE+$0375              ; Address of memory input line, 0 if none
E377-                243      IRESV   .EQ     BASE+$0377              ; Address of reserved vector routine
E379-                244      ISWI3   .EQ     BASE+$0379              ; Address of SWI1 routine
E37B-                245      ISWI2   .EQ     BASE+$037B              ; Address of SWI2 routine
E37D-                246      IFIRQ   .EQ     BASE+$037D              ; Address of FIRQ routine
E37F-                247      IIRQ    .EQ     BASE+$037F              ; Address of IRQ routine
E381-                248      ISWI    .EQ     BASE+$0381              ; Address of SWI routine
E383-                249      INMI    .EQ     BASE+$0383              ; Address of NMI routine
E385-                250      OFFSET  .EQ     BASE+$0385              ; Cassette load offset
0000-                251      ;
0000-                252      ;       General variables for monitor use
0000-                253      ;
E387-                254      HEADST  .EQ     BASE+$0387              ; Static head pointer into line buffer
E389-                255      HEADDY  .EQ     BASE+$0389              ; Dynamic head pointer into line buffer
E38B-                256      TAIL    .EQ     BASE+$038B              ; Tail pointer into line buffer
E38D-                257      MSTACK  .EQ     BASE+$038D              ; stack saved whilst memory interpreting
E38F-                258      CROW    .EQ     BASE+$038F              ; current row of cursor on display
E390-                259      CCOL    .EQ     BASE+$0390              ; current column of cursor on display
E391-                260      CPAGE   .EQ     BASE+$0391              ; current start of display page in memory
E393-                261      MSAV    .EQ     BASE+$0393              ; Saved address for memory command
E395-                262      GSAV    .EQ     BASE+$0395              ; Saved address for go command
E397-                263      NAME    .EQ     BASE+$0397              ; Saved name for cassette input output
E39D-                264      CSSTRT  .EQ     BASE+$039D              ; Saved cassette output start address
E39F-                265      CSEND   .EQ     BASE+$039F              ; Saved cassette output end address
E3A1-                266      ONLINE  .EQ     BASE+$03A1              ; flag set to zero when find or in input line
E3A2-                267      LASTC   .EQ     BASE+$03A2              ; Saved last character from input line current
E3A3-                268      CBREAK  .EQ     BASE+$03A3              ; Address of breakpoint, $FFFF if none
E3A5-                269      NBREAK  .EQ     BASE+$03A5              ; number of breakpoints to ignore before stopping user
E3A7-                270      CINST   .EQ     BASE+$03A7              ; user instruction at breakpoint address
E3A8-                271      CTRACE  .EQ     BASE+$03A8              ; number of instructions left to trace before stopping user
E3AA-                272      USRSTK  .EQ     BASE+$03AA              ; Saved user-stack pointer when user halted
E3AC-                273      TEMP    .EQ     BASE+$03AC              ; Temporary storage
E3AE-                274      BUFFER  .EQ     BASE+$03AE              ; line input buffer
0000-                275      ;               BASE+$03FF              ; end of line input buffer
0000-                276      ;
0000-                277      ;       Memory Maps
0000-                278      ;       -----------
0000-                279      ;
0000-                280      ;       Original Acorn
0000-                281      ;       $0000-$03FF     Monitor System RAM (IC5,6)
0000-                282      ;       $0400-$07FF     40-column Teletext video memory
0000-                283      ;       $0800-$08FF     40-column Teletext 6845 CRTC
0000-                284      ;;      $0900-$09FF     6522 VIA ($0980)
0000-                285      ;               REGA    b6-b0   printer output
0000-                286      ;                       b7      printer busy input
0000-                287      ;               REGB    b6-b0   keyboard ASCII input
0000-                288      ;                       b7      cassette input
0000-                289      ;               CA1             input from printer acknowledge (not used)
0000-                290      ;               CA2             output strobe to printer
0000-                291      ;               CB1             input strobe from keyboard
0000-                292      ;               CB2             output to cassette
0000-                293      ;               Timer1          used to single step
0000-                294      ;               Timer2          unused
0000-                295      ;       $0A00-$0A7F     8271 floppy disk controller
0000-                296      ;       $1000-$17FF     80-column VDU video memory
0000-                297      ;       $1800-$187F     80-column 6845 CRTC ($1840)
0000-                298      ;       $2000-$3FFF     User RAM (8K)
0000-                299      ;       $2000-$BFFF     or User RAM (8K+32K)
0000-                300      ;       $F800-$FFFF     Monitor EPROM (IC4)
0000-                301      ;
0000-                302      ;       Flex
0000-                303      ;       $0000-$7FFF     User RAM (32K)
0000-                304      ;       $0000-$BFFF     or User RAM (48K)
0000-                305      ;       $C000-$DFFF     FLEX System RAM (loaded from Disk)
0000-                306      ;       $E000-$E3FF     Monitor System RAM (IC5,6)
0000-                307      ;       $E400-$E7FF     40-column Teletext Video memory
0000-                308      ;       $E800-$E8FF     40-column Teletext 6845 CRTC
0000-                309      ;       $E800-$E87F     80-column 6845 CRTC ($E840)
0000-                310      ;       $E900-$E9FF     6522 VIA ($E980)
0000-                311      ;               REGA    b6-b0   printer output
0000-                312      ;                       b7      printer busy input
0000-                313      ;               REGB    b6-b0   keyboard ASCII input
0000-                314      ;                       b7      cassette input
0000-                315      ;               CA1             input from printer acknowledge (not used)
0000-                316      ;               CA2             output strobe to printer
0000-                317      ;               CB1             input strobe from keyboard
0000-                318      ;               CB2             output to cassette
0000-                319      ;               Timer1          used to single step
0000-                320      ;               Timer2          unused
0000-                321      ;       $EA00-$EA7F     8271 floppy disk controller
0000-                322      ;       $F000-$F7FF     80-column VDU video memory
0000-                323      ;       $F800-$FFFF     Monitor EPROM (IC4)
0000-                324      ;
F800-                325              .OR     MPROM
F800-                326      ;
F800-                327                                      ; ****** Hardware Reset Starts Here ******
F800-                328      ;
F800-86 E3           329 ( 2) RESET:  LDA     #MONDP          ; Set up direct page
F802-1F 8B           330 ( 7)         TFR     A,DP
F804-                331              .DP     MONDP
F804-8E FF 25        332 ( 3)         LDX     #PTAB1          ; ROM table start
F807-CE E3 5B        333 ( 3)         LDU     #RTAB1          ; RAM table start
F80A-A6 80           334 ( 7) RST1:   LDA     ,X+             ; Copy ROM
F80C-A7 C0           335 ( 7)         STA     ,U+             ; to RAM
F80E-8C FF 51        336 ( 4)         CMPX    #PTAB2          ; until end of table
F811-26 F7           337 ( 3)         BNE     RST1
F813-10 DE 5B        338 ( 6)         LDS     <STACK          ; Set up stack pointer
F816-                339      ;
F816-                340              .DO     VER=490
F816-BE F7 FE        341 ( 6)         LDX     MPROM-2
F819-8C A5 5A        342 ( 4)         CMPX    #$A55A          ; Check for extra ROM,
F81C-26 04           343 ( 3)         BNE     STRT1           ; not there,
F81E-AD 9F F7 FC     344 (13)         JSR     [MPROM-4]       ; else call it
F822-                345              .FI
F822-                346      ;
F822-             S  347              .DO     VER=495
F822-             S  348              .DB     $17,$06,$63     ; 'LBSR CONCHR-3'
F822-             S  349              NOP
F822-             S  350              NOP
F822-             S  351              NOP
F822-             S  352              NOP
F822-             S  353              NOP
F822-             S  354              NOP
F822-             S  355              NOP
F822-             S  356              NOP
F822-             S  357              NOP
F822-                358              .FI
F822-                359      ;
F822-CE FB EA        360 ( 3) STRT1:  LDU     #BACK           ; Put monitor return on to stack
F825-34 40           361 ( 7)         PSHS    U
F827-CC 00 0C        362 ( 3)         LDD     #$0C
F82A-34 02           363 ( 6) STRT2:  PSHS    A               ; Put dummy registers onto stack
F82C-5A              364 ( 2)         DECB
F82D-26 FB           365 ( 3)         BNE     STRT2
F82F-10 DF AA        366 ( 6)         STS     <USRSTK         ; Save stack pointer
F832-8E E3 AE        367 ( 3)         LDX     #BUFFER         ; Get start of buffer
F835-9F 89           368 ( 5)         STX     <HEADDY         ; and set up pointers
F837-9F 87           369 ( 5)         STX     <HEADST
F839-9F 8B           370 ( 5)         STX     <TAIL
F83B-17 00 E7        371 ( 9)         LBSR    CRTCI           ; Initialise CRT controller
F83E-17 00 D1        372 ( 9)         LBSR    VIAI            ; and VIA chips
F841-0F A2           373 ( 6)         CLR     <LASTC          ; Set no saved character
F843-17 04 00        374 ( 9)         LBSR    BRKOUT          ; Remove if exists
F846-8E FF FF        375 ( 3)         LDX     #$FFFF          ; then set none existing
F849-                376      ;
F849-                377              .DO     VER=490
F849-9F A3           378 ( 5)         STX     <CBREAK
F84B-1C EF           379 ( 3)         ANDCC   #$EF            ; CLI: Allow interrupts
F84D-                380              .FI
F84D-                381      ;
F84D-             S  382              .DO     VER=495
F84D-             S  383              JMP     MCASIN
F84D-             S  384              .DB     $EF             ; Packing ?
F84D-                385              .FI
F84D-                386      ;
F84D-                387              .DP     0
F84D-86 2A           388 ( 2) MON:    LDA     #PROMPT         ; Send prompt
F84F-BE E3 75        389 ( 6)         LDX     >LINEPT         ; unless
F852-26 03           390 ( 3)         BNE     MON1            ; memory input
F854-17 01 CA        391 ( 9)         LBSR    CONOUT
F857-                392      ;
F857-B7 E3 A1        393 ( 5) MON1:   STA     >ONLINE         ; Set no CR yet
F85A-86 E3           394 ( 2) PARSE:  LDA     #MONDP
F85C-1F 8B           395 ( 7)         TFR     A,DP            ; Set direct page
F85E-                396              .DP     MONDP
F85E-9E 75           397 ( 5)         LDX     <LINEPT         ; See if mem input,
F860-27 04           398 ( 3)         BEQ     PARSEC          ; if so,
F862-A6 84           399 ( 5)         LDA     ,X              ; then see if null yet
F864-27 41           400 ( 3)         BEQ     MEND            ; End if is null
F866-8D 17           401 ( 7) PARSEC: BSR     CONCHR          ; Get input
F868-27 E3           402 ( 3)         BEQ     MON             ; prompt on CR
F86A-9E 71           403 ( 5)         LDX     <CMNDI          ; else command table search
F86C-17 01 37        404 ( 9)         LBSR    DISPCH
F86F-20 E9           405 ( 3)         BRA     PARSE
F871-                406      ;
F871-                407      ; Enter here for monitor to use memory input line (X) is start of line, ends with a null.
F871-                408      ; multiple input lines are allowed, each line ends with carriage return.
F871-                409      ;
F871-                410      ; Exits with (a) zero if all ok, else (a) is $FF if found null too early,
F871-                411      ; else (a) is character causing error.
F871-                412      ;
F871-                413              .DP     0
F871-34 08           414 ( 6) MEMUSE: PSHS    DP
F873-10 FF E3 8D     415 ( 7)         STS     MSTACK          ; Save stack for return.
F877-BF E3 75        416 ( 6)         STX     LINEPT          ; Save pointer in memory
F87A-7F E3 A2        417 ( 7)         CLR     LASTC           ; Set none saved
F87D-20 CE           418 ( 3)         BRA     MON             ; and call monitor
F87F-86 0D           419 ( 2) CONCHR: LDA     #CR             ; Assume CR now
F881-7D E3 A1        420 ( 7)         TST     ONLINE          ; and if found CR then
F884-27 06           421 ( 3)         BEQ     CON1            ; is correct
F886-8D 08           422 ( 7)         BSR     CONIN           ; Get input
F888-81 0D           423 ( 2)         CMPA    #CR             ; If not CR then
F88A-26 03           424 ( 3)         BNE     CON2            ; done
F88C-7F E3 A1        425 ( 7) CON1:   CLR     ONLINE          ; Set found CR
F88F-39              426 ( 5) CON2:   RTS
F890-                427      ;
F890-                428      ; Console input routine, gets character from keyboard buffer or memory it finds
F890-                429      ; null in memory then returns to to caller with error $FF.
F890-                430      ;
F890-                431              .DP     MONDP
F890-34 18           432 ( 8) CONIN:  PSHS    DP,X
F892-86 E3           433 ( 2)         LDA     #MONDP          ; Set up
F894-1F 8B           434 ( 7)         TFR     A,DP            ; direct page
F896-96 A2           435 ( 4)         LDA     <LASTC          ; Saved one?
F898-27 04           436 ( 3)         BEQ     CON5            ; none saved
F89A-0F A2           437 ( 6)         CLR     <LASTC          ; not saved anymore
F89C-35 98           438 (10)         PULS    DP,X,PC
F89E-                439      ;
F89E-9E 75           440 ( 5) CON5:   LDX     <LINEPT         ; see if mem input
F8A0-27 0E           441 ( 3)         BEQ     CON3            ; no, use buffer
F8A2-A6 80           442 ( 7)         LDA     ,X+             ; Get men value
F8A4-26 0E           443 ( 3)         BNE     CON4            ; ok if not null
F8A6-4A              444 ( 2)         DECA                    ; Set to $FF
F8A7-10 DE 8D        445 ( 6) MEND:   LDS     <MSTACK         ; clear mem
F8AA-0F 75           446 ( 6)         CLR     <LINEPT+0       ; input
F8AC-0F 76           447 ( 6)         CLR     <LINEPT+1
F8AE-35 88           448 ( 8)         PULS    DP,PC           ; and return to caller
F8B0-AD 9F E3 67     449 (13) CON3:   JSR     [CINADR]        ; Get console input
F8B4-9F 75           450 ( 5) CON4:   STX     <LINEPT         ; store new mem pointer
F8B6-35 98           451 (10)         PULS    DP,X,PC
F8B8-                452      ;
F8B8-                453      ; This routine prints the registers from the stack as pointed to by usrstk,
F8B8-                454      ; then prints usrstk itself.  Also prints five bytes starting at (PC)
F8B8-                455      ;
F8B8-8E FF 96        456 ( 3) EXREG:  LDX     #TITLES         ; Headings
F8BB-8D 2F           457 ( 7)         BSR     STRING          ; printed first
F8BD-DE AA           458 ( 5)         LDU     <USRSTK
F8BF-C6 04           459 ( 2)         LDB     #$04            ; ie, CC,A,B,DP.
F8C1-A6 C0           460 ( 7) EX1:    LDA     ,U+             ; Get data
F8C3-17 01 D1        461 ( 9)         LBSR    OPARSP          ; output as 2 hex digits
F8C6-5A              462 ( 2)         DECB
F8C7-26 F8           463 ( 3)         BNE     EX1             ; until all 4 output
F8C9-C6 04           464 ( 2)         LDB     #$04            ; ie, X, Y, U, PC
F8CB-AE C1           465 ( 9) EX2:    LDX     ,U++            ; get 2 bytes
F8CD-17 01 A5        466 ( 9)         LBSR    OPXREG          ; as 4 hex digits
F8D0-5A              467 ( 2)         DECB
F8D1-26 F8           468 ( 3)         BNE     EX2             ; until all output
F8D3-9E AA           469 ( 5)         LDX     <USRSTK         ; then put out stack
F8D5-17 01 9D        470 ( 9)         LBSR    OPXREG          ; address.
F8D8-EE 0A           471 ( 7)         LDU     $0A,X           ; Get user PC value
F8DA-8E FF BD        472 ( 3)         LDX     #PCMESS         ; Send
F8DD-8D 0D           473 ( 7)         BSR     STRING          ; title
F8DF-C6 05           474 ( 2)         LDB     #$05            ; then 5 bytes
F8E1-A6 C0           475 ( 7) EX3:    LDA     ,U+
F8E3-17 01 B1        476 ( 9)         LBSR    OPARSP
F8E6-5A              477 ( 2)         DECB
F8E7-26 F8           478 ( 3)         BNE     EX3
F8E9-                479      ;
F8E9-                480      ; Output the string CR, LF to console
F8E9-                481      ;
F8E9-8E FF 93        482 ( 3) OPCRLF: LDX     #SCRLF          ; String address of CR, LF
F8EC-                483      ;
F8EC-                484      ; Output the string pointed to by X until a null,
F8EC-                485      ; leaves X pointing to null+1, other registers intact
F8EC-                486      ;
F8EC-34 02           487 ( 6) STRING: PSHS    A               ; Save A
F8EE-A6 80           488 ( 7) STRNG1: LDA     ,X+             ; Get data
F8F0-27 05           489 ( 3)         BEQ     EOTXT           ; finish if null
F8F2-17 01 2C        490 ( 9)         LBSR    CONOUT          ; else output
F8F5-20 F7           491 ( 3)         BRA     STRNG1          ; and repeat.
F8F7-35 82           492 ( 8) EOTXT:  PULS    A,PC            ; Get A back and return
F8F9-                493      ;
F8F9-                494      ; Calculate apparent address of cursor without allowing for memory wrap around, result in D.
F8F9-                495      ;
F8F9-                496      CCOFST:
F8F9-                497              .DO     VER=490
F8F9-86 28           498 ( 2)         LDA     #COLS
F8FB-                499              .FI
F8FB-                500      ;
F8FB-             S  501              .DO     VER=495
F8FB-             S  502              LDA     <$01
F8FB-                503              .FI
F8FB-                504      ;
F8FB-D6 8F           505 ( 4)         LDB     <CROW
F8FD-3D              506 (11)         MUL
F8FE-DB 90           507 ( 4)         ADDB    <CCOL
F900-89 00           508 ( 2)         ADCA    #0
F902-D3 91           509 ( 6)         ADDD    <CPAGE
F904-39              510 ( 5)         RTS
F905-                511      ;
F905-                512      ; Calculate real address of cursor in memory space, result returned in X.
F905-                513      ;
F905-34 06           514 ( 7) CCLOCN: PSHS    D
F907-8D F0           515 ( 7)         BSR     CCOFST          ; Apparent address.
F909-84 03           516 ( 2)         ANDA    #WRPMSK         ; Wrap around in 1K or 2K page
F90B-C3 E4 00        517 ( 4)         ADDD    #VPAGE          ; Add start of video page
F90E-1F 01           518 ( 7)         TFR     D,X
F910-35 86           519 ( 9)         PULS    D,PC            ; Unsave and return
F912-                520      ;
F912-                521      ; Initialise Versatile Interface Adapter (VIA)
F912-                522      ;
F912-CC EF D0        523 ( 3) VIAI:   LDD     #IKPCR*256+IKIER
F915-8E E9 80        524 ( 3)         LDX     #KVIA           ; Point to VIA.
F918-A7 0C           525 ( 6)         STA     KPCR-KVIA,X     ; Peripheral control register
F91A-E7 0E           526 ( 6)         STB     KIER-KVIA,X     ; Interrupt enable register
F91C-86 7F           527 ( 2)         LDA     #$7F            ; Printer output (7 bits) plus
F91E-A7 03           528 ( 6)         STA     KDDRA-KVIA,X    ; cassette input on a side
F920-A6 0D           529 ( 6)         LDA     KIFR-KVIA,X     ; Cancel any interrupts present
F922-A7 0D           530 ( 6)         STA     KIFR-KVIA,X
F924-39              531 ( 5)         RTS
F925-                532      ;
F925-                533      ; Initialise CRT controller on VDU card, R or S version
F925-                534      ;
F925-                535      CRTCI:
F925-                536      ;
F925-                537              .DO     VER=490
F925-8E FF 0D        538 ( 3)         LDX     #CRTCSV         ; Table for S version
F928-                539              .FI
F928-                540      ;
F928-             S  541              .DO     VER=495
F928-             S  542              LDX     #$E300          ; ??
F928-                543              .FI
F928-                544      ;
F928-CC 0D AA        545 ( 3)         LDD     #PAGHI+1*256+$AA ; Test the page register
F92B-FD E8 00        546 ( 6)         STD     CRTC            ; (low byte) for read/write ability
F92E-F1 E8 01        547 ( 5)         CMPB    CRTC+1
F931-27 02           548 ( 3)         BEQ     CRTC11          ; If so, then V version
F933-30 0C           549 ( 1)         LEAX    $C,X            ; 'LEAX CRTCRV-CRTCSV,X'        ; else get R table instead
F935-86 0B           550 ( 2) CRTC11: LDA     #12-1           ; Set up 12 registers
F937-E6 86           551 ( 6) CRTC12: LDB     A,X             ; Get data and store it in correct register
F939-FD E8 00        552 ( 6)         STD     CRTC
F93C-4A              553 ( 2)         DECA
F93D-2A F8           554 ( 3)         BPL     CRTC12          ; Repeat until all 12 done
F93F-                555      ;
F93F-                556      ; Reset display to a blank page with cursor at top left of screen
F93F-                557      ;
F93F-0F 8F           558 ( 6) CLRALL: CLR     <CROW           ; Row 0
F941-0F 90           559 ( 6)         CLR     <CCOL           ; Column 0
F943-0F 91           560 ( 6)         CLR     <CPAGE+0        ; Current page set
F945-0F 92           561 ( 6)         CLR     <CPAGE+1        ; to start of display memory
F947-17 00 9C        562 ( 9)         LBSR    SETTOP          ; Set page in CRTC chip
F94A-17 00 A1        563 ( 9)         LBSR    SETCUR          ; and set cursor in CRTC chip
F94D-                564      ;
F94D-                565      ; Clear the display memory to all blanks.
F94D-                566      ;
F94D-CC 20 20        567 ( 3) CLRSCN: LDD     #SPACE*256+SPACE ; Two spaces
F950-8E E4 00        568 ( 3)         LDX     #VPAGE          ; Start of display memory
F953-ED 81           569 ( 9) CLRS1:  STD     ,X++            ; Store two blanks
F955-8C E8 00        570 ( 4)         CMPX    #VPAGE+PSIZE    ; and repeat
F958-26 F9           571 ( 3)         BNE     CLRS1           ; until done all page
F95A-39              572 ( 5)         RTS
F95B-                573      ;
F95B-                574      ; This routine used to put a character to the VDU, handling CR, LF, backspace and form feed.
F95B-                575      ; All registers are saved.
F95B-                576      ;
F95B-34 7F           577 (15) DISPLA: PSHS    U,Y,X,DP,B,A,CC ; Save registers.
F95D-C6 E3           578 ( 2)         LDB     #MONDP
F95F-1F 9B           579 ( 7)         TFR     B,DP
F961-9E 6F           580 ( 5)         LDX     <FUNCTI         ; Get function table.
F963-1A 10           581 ( 3)         ORCC    #IRQ            ; Stop interrupts since not re-entrant
F965-8D 3F           582 ( 7)         BSR     DISPCH          ; Jump on function table
F967-35 FF           583 (17)         PULS    U,Y,X,DP,B,A,CC,PC      ; then restore and return
F969-                584      ;
F969-                585      ; This routine puts a character on display and moves cursor
F969-                586      ;
F969-8D 9A           587 ( 7) SIMCHR: BSR     CCLOCN          ; Find location in memory
F96B-A7 84           588 ( 5)         STA     ,X              ; and store character
F96D-0C 90           589 ( 6)         INC     <CCOL           ; move cursor across
F96F-96 90           590 ( 4)         LDA     <CCOL           ; then done if
F971-                591      ;
F971-                592              .DO     VER=490
F971-81 28           593 ( 2)         CMPA    #COLS           ; all columns
F973-                594              .FI
F973-                595      ;
F973-             S  596              .DO     VER=495
F973-             S  597              CMPA    <$01            ; ??
F973-                598              .FI
F973-                599      ;
F973-26 0E           600 ( 3)         BNE     SIM1            ; not yet filled
F975-0F 90           601 ( 6)         CLR     <CCOL           ; Do CR
F977-                602      ;
F977-                603      ; Move cursor down one line, scroll display if required
F977-                604      ;
F977-0C 8F           605 ( 6) DOLF:   INC     <CROW           ; Down a row
F979-96 8F           606 ( 4)         LDA     <CROW
F97B-                607      ;
F97B-                608              .DO     VER=490
F97B-81 19           609 ( 2)         CMPA    #ROWS           ; Last row yet
F97D-                610              .FI
F97D-                611      ;
F97D-             S  612              .DO     VER=495
F97D-             S  613              CMPA    <$06            ; ??
F97D-                614              .FI
F97D-                615      ;
F97D-26 04           616 ( 3)         BNE     SIM1            ; if not then done,
F97F-0A 8F           617 ( 6)         DEC     <CROW           ; else back up
F981-8D 40           618 ( 7)         BSR     SCROLL          ; and scroll instead
F983-20 69           619 ( 3) SIM1:   BRA     SETCUR          ; then set new cursor
F985-                620      ;
F985-                621      ; Move cursor back erasing last character.
F985-                622      ;
F985-8D 08           623 ( 7) DORUB:  BSR     BSONE           ; Back up cursor
F987-86 20           624 ( 2)         LDA     #SPACE
F989-8D D0           625 ( 7)         BSR     DISPLA          ; then blank last character,
F98B-8D 02           626 ( 7)         BSR     BSONE           ; and back up again
F98D-20 5F           627 ( 3) LF98D:  BRA     SETCUR          ; then set cursor up
F98F-                628      ;
F98F-                629      ; Back cursor up allowing line and row underflow.
F98F-                630      ;
F98F-0A 90           631 ( 6) BSONE:  DEC     <CCOL           ; Left move cursor
F991-2A 0C           632 ( 3)         BPL     BS1             ; No under flow
F993-                633      ;
F993-                634              .DO     VER=490
F993-86 27           635 ( 2)         LDA     #COLS-1         ; else set to
F995-                636              .FI
F995-                637      ;
F995-             S  638              .DO     VER=495
F995-             S  639              LDA     <$0C            ; ??
F995-                640              .FI
F995-                641      ;
F995-97 90           642 ( 4)         STA     <CCOL           ; right margin
F997-0A 8F           643 ( 6)         DEC     <CROW           ; and up one row
F999-2A 04           644 ( 3)         BPL     BS1             ; No row underflow
F99B-0F 8F           645 ( 6)         CLR     <CROW
F99D-0F 90           646 ( 6)         CLR     <CCOL
F99F-39              647 ( 5) BS1:    RTS
F9A0-                648      ;
F9A0-                649      ; Dispatch routine looks up a character in a table,
F9A0-                650      ; character in A, table address ,X
F9A0-                651      ;
F9A0-                652      ; Table format is:      First byte, number of entries 1 to 255
F9A0-                653      ;
F9A0-                654      ;       Repeat for each entry:  character to match with,
F9A0-                655      ;                               2-byte offset from start of this table
F9A0-                656      ;                               of routine to jump to if characters match
F9A0-                657      ;
F9A0-                658      ;       flag byte:  control if no match found:
F9A0-                659      ;
F9A0-                660      ;       positive: next word is offset of default routine
F9A0-                661      ;       zero:     return to calling program
F9A0-                662      ;       negative: next word is address of another table to search
F9A0-                663      ;
F9A0-EC 84           664 ( 6) DIS2:   LDD     ,X              ; Get address of new table,
F9A2-ED 62           665 ( 7)         STD     2,S             ; replace old on stack,
F9A4-35 56           666 (11)         PULS    D,X,U           ; and begin again
F9A6-34 56           667 (11) DISPCH: PSHS    D,X,U           ; Save registers
F9A8-E6 81           668 ( 8)         LDB     ,X++            ; Get length and move to offset.
F9AA-A1 1F           669 ( 6) DIS1:   CMPA    -1,X            ; Compare characters
F9AC-27 0B           670 ( 3)         BEQ     DIS3            ; Found it, else,
F9AE-30 03           671 ( 1)         LEAX    3,X             ; move down.
F9B0-5A              672 ( 2)         DECB                    ; Repeat until
F9B1-26 F7           673 ( 3)         BNE     DIS1            ; done
F9B3-6D 1F           674 ( 8)         TST     -1,X            ; Test flag byte.
F9B5-27 0A           675 ( 3)         BEQ     DIS4            ; Zero means return
F9B7-2B E7           676 ( 3)         BMI     DIS2            ; search new table, else
F9B9-EC 84           677 ( 6) DIS3:   LDD     ,X              ; get offset and
F9BB-E3 62           678 ( 8)         ADDD    2,S             ; add start of table, then
F9BD-ED 64           679 ( 7)         STD     4,S             ; store in stack.
F9BF-35 96           680 (11)         PULS    D,X,PC          ; Restore and go to routine
F9C1-35 D6           681 (13) DIS4:   PULS    D,X,U,PC        ; Return to caller
F9C3-                682      ;
F9C3-                683      ; Scroll the display up one line, leave cursor at same position on screen, leave registers intact
F9C3-                684      ;
F9C3-DC 91           685 ( 5) SCROLL: LDD     <CPAGE          ; Get start of page
F9C5-C3 03 E8        686 ( 4)         ADDD    #ROWS*COLS      ; then move off end, $03E8 (40-column) or $07D0 (80-column)
F9C8-8E E4 00        687 ( 3)         LDX     #VPAGE          ; Actual memory address
F9CB-CE 20 20        688 ( 3)         LDU     #SPACE*256+SPACE ; Double space
F9CE-                689      ;
F9CE-                690              .DO     VER=490
F9CE-10 8E 00 14     691 ( 4)         LDY     #COLS/2         ; Number to blank
F9D2-                692              .FI
F9D2-                693      ;
F9D2-             S  694              .DO     VER=495
F9D2-             S  695              LDY     <$0D            ; ??
F9D2-             S  696              NOP
F9D2-                697              .FI
F9D2-                698      ;
F9D2-84 03           699 ( 2) SCR1:   ANDA    #WRPMSK         ; Wrap around in 1K or 2K
F9D4-EF 8B           700 (10)         STU     D,X             ; and put 2 blanks
F9D6-C3 00 02        701 ( 4)         ADDD    #2              ; Move up and
F9D9-31 3F           702 ( 1)         LEAY    -1,Y            ; repeat until
F9DB-26 F5           703 ( 3)         BNE     SCR1            ; line done
F9DD-83 03 E8        704 ( 4)         SUBD    #ROWS*COLS      ; Move to second line now, $03E8 (40-column) or $07D0 (80-column)
F9E0-84 03           705 ( 2)         ANDA    #WRPMSK         ; wrap around and
F9E2-DD 91           706 ( 5)         STD     <CPAGE          ; set as new page
F9E4-8D 08           707 ( 7)         BSR     SETCUR          ; Put cursor back in position
F9E6-                708      ;
F9E6-                709      ; Put page address into CRT controller.
F9E6-                710      ;
F9E6-9E 91           711 ( 5) SETTOP: LDX     <CPAGE          ; Get page
F9E8-86 0C           712 ( 2)         LDA     #PAGHI          ; Point to page start register
F9EA-20 09           713 ( 3)         BRA     SETPAR          ; then enter parameters
F9EC-                714      ;
F9EC-                715      ; Do a carriage return by setting column to 0
F9EC-                716      ;
F9EC-0F 90           717 ( 6) DOCR:   CLR     <CCOL
F9EE-                718      ;
F9EE-                719      ; Set cursor register in CRT controller.
F9EE-                720      ;
F9EE-17 FF 08        721 ( 9) SETCUR: LBSR    CCOFST          ; Get cursor address, no wrap around
F9F1-1F 01           722 ( 7)         TFR     D,X             ; into X
F9F3-86 0E           723 ( 2)         LDA     #CURHI          ; Point to cursor register
F9F5-                724      ;
F9F5-                725      ; Put 2 byte value into CRT controller, value in X, high byte register number in A
F9F5-                726      ;
F9F5-34 10           727 ( 7) SETPAR: PSHS    X               ; Get high byte
F9F7-35 04           728 ( 6)         PULS    B               ; Set register
F9F9-FD E8 00        729 ( 6)         STD     CRTC            ; and data move to low byte
F9FC-4C              730 ( 2)         INCA                    ; Get low byte
F9FD-35 04           731 ( 6)         PULS    B               ; Set register
F9FF-FD E8 00        732 ( 6)         STD     CRTC            ; and data.
FA02-39              733 ( 5)         RTS
FA03-                734      ;
FA03-                735      ; This routine puts keyboard input into line buffer
FA03-                736      ; If no room then ignores character, else echoes to display
FA03-                737      ; If echo is switched on handles rubout unless line buffer is switched off
FA03-                738      ;
FA03-D6 60           739 ( 4) HAVCHR: LDB     <ECHOF
FA05-2A 04           740 ( 3)         BPL     HAV3            ; Buffer off, so no rubout
FA07-81 7F           741 ( 2)         CMPA    #RUBCH
FA09-27 23           742 ( 3)         BEQ     BSP1            ; Go do rubout
FA0B-8D 37           743 ( 7) HAV3:   BSR     PUTCHR          ; Put into buffer
FA0D-27 43           744 ( 3)         BEQ     PUT1            ; No room, do not echo
FA0F-5D              745 ( 2)         TSTB                    ; If buffer off, then no
FA10-2A 08           746 ( 3)         BPL     HAV4            ; line feed on CR input
FA12-81 0D           747 ( 2)         CMPA    #CR
FA14-26 06           748 ( 3)         BNE     KBECHO          ; Not CR, so no
FA16-8D 04           749 ( 7)         BSR     KBECHO          ; echo of a linefeed
FA18-86 0A           750 ( 2)         LDA     #LF
FA1A-9F 87           751 ( 5) HAV4:   STX     <HEADST         ; Move static pointer up
FA1C-                752      ;
FA1C-                753      ; Put character in A to console output if echo on
FA1C-                754      ;
FA1C-D6 60           755 ( 4) KBECHO: LDB     <ECHOF          ; See if echo on
FA1E-58              756 ( 2)         LSLB                    ; Need bit 6
FA1F-2A 31           757 ( 3)         BPL     PUT1            ; Not on if zero
FA21-                758      ;
FA21-                759      ; Console output routine, sends to printer also if switched on
FA21-                760      ;
FA21-                761              .DP     0
FA21-7D E3 61        762 ( 7) CONOUT: TST     PFLAG           ; If printer off then
FA24-27 04           763 ( 3)         BEQ     CANOP1          ; value is zero
FA26-AD 9F E3 6D     764 (13)         JSR     [PRINT1]        ; else call printer
FA2A-6E 9F E3 65     765 ( 9) CANOP1: JMP     [COPADR]        ; then console output
FA2E-                766              .DP     MONDP
FA2E-9E 89           767 ( 5) BSP1:   LDX     <HEADDY         ; End of line, if at start of line
FA30-9C 87           768 ( 6)         CMPX    <HEADST
FA32-27 1E           769 ( 3)         BEQ     PUT1            ; then nothing to rubout
FA34-8C E3 AE        770 ( 4)         CMPX    #BUFFER         ; Do cyclic
FA37-26 03           771 ( 3)         BNE     BSP2
FA39-30 88 52        772 ( 1)         LEAX    BUFLEN,x        ; decrement of pointer
FA3C-30 1F           773 ( 1) BSP2:   LEAX    -1,x
FA3E-9F 89           774 ( 5)         STX     <HEADDY         ; Set new end of line
FA40-96 5F           775 ( 4)         LDA     <BSECHO         ; and echo a backspace
FA42-20 D8           776 ( 3)         BRA     KBECHO
FA44-                777      ;
FA44-                778      ; Put character into buffer if room, return Z=0, else return Z=1
FA44-                779      ;
FA44-9E 89           780 ( 5) PUTCHR: LDX     <HEADDY         ; Get pointer
FA46-8D 0B           781 ( 7)         BSR     BUMPU           ; If no room, then
FA48-9C 8B           782 ( 6)         CMPX    <TAIL           ; pointers equal,
FA4A-27 06           783 ( 3)         BEQ     PUT1            ; so done
FA4C-A7 84           784 ( 5)         STA     ,X              ; Store it and
FA4E-9F 89           785 ( 5)         STX     <HEADDY         ; set new pointer
FA50-1C FB           786 ( 3)         ANDCC   #255-ZERO       ; Clear Z flag
FA52-39              787 ( 5) PUT1:   RTS
FA53-                788      ;
FA53-                789      ; Cyclic increment of buffer pointers.
FA53-                790      ;
FA53-30 01           791 ( 1) BUMPU:  LEAX    1,X
FA55-8C E4 00        792 ( 4)         CMPX    #BUFFER+BUFLEN
FA58-26 03           793 ( 3)         BNE     ANRTS
FA5A-8E E3 AE        794 ( 3)         LDX     #BUFFER
FA5D-39              795 ( 5) ANRTS:  RTS
FA5E-                796      ;
FA5E-                797      ; Get character from buffer, if none then clears interrupt
FA5E-                798      ; mask and waits. all registers saved, including CC
FA5E-                799      ;
FA5E-                800              .DP     0
FA5E-34 11           801 ( 8) GETCHR: PSHS    X,CC            ; Save and
FA60-20 02           802 ( 3)         BRA     GETCH1          ; skip wait
FA62-3C EF           803 (20) GETCH2: CWAI    #255-IRQ        ; Wait for an interrupt
FA64-BE E3 8B        804 ( 6) GETCH1: LDX     TAIL            ; Get tail pointer
FA67-BC E3 87        805 ( 7)         CMPX    HEADST          ; If equals static head
FA6A-27 F6           806 ( 3)         BEQ     GETCH2          ; then no character
FA6C-8D E5           807 ( 7)         BSR     BUMPU           ; else move up
FA6E-A6 84           808 ( 5)         LDA     ,X              ; and get it.
FA70-BF E3 8B        809 ( 6)         STX     TAIL            ; Set new tail
FA73-35 91           810 (10)         PULS    CC,X,PC
FA75-                811      ;
FA75-                812      ; Output X register as four hex digits to console, all registers saved
FA75-                813      ;
FA75-                814              .DP     0
FA75-34 06           815 ( 7) OPXREG: PSHS    D
FA77-1F 10           816 ( 7)         TFR     X,D
FA79-8D 06           817 ( 7)         BSR     OPAREG
FA7B-1F 98           818 ( 7)         TFR     B,A
FA7D-8D 18           819 ( 7)         BSR     OPARSP
FA7F-35 86           820 ( 9)         PULS    D,PC
FA81-                821      ;
FA81-                822      ; Output a register as two hex digits to console, all registers saved except a
FA81-                823      ;
FA81-34 02           824 ( 6) OPAREG: PSHS    A
FA83-44              825 ( 2)         LSRA
FA84-44              826 ( 2)         LSRA
FA85-44              827 ( 2)         LSRA
FA86-44              828 ( 2)         LSRA
FA87-8D 04           829 ( 7)         BSR     HEXOUT          ; Left nibble
FA89-A6 E0           830 ( 7)         LDA     ,S+             ; Get byte back and
FA8B-84 0F           831 ( 2)         ANDA    #15             ; do right nibble
FA8D-                832      ;
FA8D-                833      ; Output A as a single hex digit.
FA8D-                834      ;
FA8D-8B 30           835 ( 2) HEXOUT: ADDA    #'0'
FA8F-81 39           836 ( 2)         CMPA    #'9'
FA91-23 02           837 ( 3)         BLS     HEX2
FA93-8B 07           838 ( 2)         ADDA    #'A'-'9'-1
FA95-20 8A           839 ( 3) HEX2:   BRA     CONOUT          ; Output and return
FA97-                840      ;
FA97-                841      ; Output a hex digit folowed by a space
FA97-                842      ;
FA97-8D E8           843 ( 7) OPARSP: BSR     OPAREG
FA99-86 20           844 ( 2)         LDA     #SPACE
FA9B-20 F8           845 ( 3)         BRA     HEX2
FA9D-                846      ;
FA9D-                847      ; Printer routine, this interfaces to anadex or centronics parallel interface printers
FA9D-                848      ;
FA9D-                849              .DP     0
FA9D-34 46           850 ( 9) PRINT:  PSHS    D,U
FA9F-CE E9 80        851 ( 3)         LDU     #KVIA           ; Point to VIA
FAA2-B1 E3 62        852 ( 5)         CMPA    PNEW            ; If spec'd symbol then
FAA5-27 0E           853 ( 3)         BEQ     PEXIT           ; do not send
FAA7-E6 4F           854 ( 6) PWAIT1: LDB     KORA2-KVIA,U    ; Check if busy
FAA9-2B FC           855 ( 3)         BMI     PWAIT1          ; If so then wait
FAAB-A7 41           856 ( 6)         STA     KORA-KVIA,U     ; Store data
FAAD-C6 ED           857 ( 2)         LDB     #IKPCR-PSTRB    ; then low strobe
FAAF-E7 4C           858 ( 6)         STB     KPCR-KVIA,U
FAB1-C6 EF           859 ( 2)         LDB     #IKPCR          ; and high strobe
FAB3-E7 4C           860 ( 6)         STB     KPCR-KVIA,U
FAB5-35 C6           861 (11) PEXIT:  PULS    PC,U,B,A        ; Pull registers and return
FAB7-                862      ;
FAB7-                863      ; These tables are the decision tables for the memory examine and change function
FAB7-                864      ;
FAB7-                865              .DP     MONDP
FAB7-08              866      MTABA:  .DB     MTABAE-MTABA/3-1        ; number of entries
FAB8-56              867              .AS     'V'
FAB9-00 2C           868              .DW     VADDR-MTABA     ; Modify break address and memory
FABB-47              869              .AS     'G'
FABC-00 34           870              .DW     GADDR-MTABA     ; Modify go address and memory
FABE-50              871              .AS     'P'
FABF-00 3C           872              .DW     PADDR-MTABA     ; Modify proceed address and memory
FAC1-52              873              .AS     'R'
FAC2-00 42           874              .DW     RADDR-MTABA     ; Modify register locations
FAC4-20              875              .DB     SPACE
FAC5-00 51           876              .DW     SPACEA-MTABA
FAC7-2C              877              .DB     COMMA
FAC8-00 7A           878              .DW     COMMAA-MTABA
FACA-3B              879              .DB     SEMIC
FACB-00 8A           880              .DW     SEMICA-MTABA
FACD-2D              881              .DB     MINUS
FACE-00 8E           882              .DW     MINUSA-MTABA
FAD0-01              883              .DB     1
FAD1-00 71           884              .DW     NOTA-MTABA
FAD3-                885      MTABAE: .EQ     $
FAD3-                886      ;
FAD3-04              887      MTABB:  .DB     MTABBE-MTABB/3-1
FAD4-20              888              .DB     SPACE
FAD5-00 5E           889              .DW     SPACEB-MTABB
FAD7-2C              890              .DB     COMMA
FAD8-00 8D           891              .DW     COMMAB-MTABB
FADA-3B              892              .DB     SEMIC
FADB-00 69           893              .DW     SEMICB-MTABB
FADD-2D              894              .DB     MINUS
FADE-00 72           895              .DW     MINUSB-MTABB
FAE0-01              896              .DB     1
FAE1-00 7B           897              .DW     NOTB-MTABB
FAE3-                898      MTABBE: .EQ     $
FAE3-                899      ;
FAE3-                900      ; Memory examine and change routine.
FAE3-                901      ;
FAE3-17 01 60        902 ( 9) VADDR:  LBSR    BRKOUT          ; Take out any break
FAE6-CE E3 A3        903 ( 3)         LDU     #CBREAK         ; point to break address store
FAE9-20 03           904 ( 3)         BRA     ADDR1
FAEB-CE E3 95        905 ( 3) GADDR:  LDU     #GSAV           ; point to go address store
FAEE-10 AE C4        906 ( 7) ADDR1:  LDY     ,U              ; Get initial value
FAF1-20 3E           907 ( 3)         BRA     GDATA
FAF3-DE AA           908 ( 5) PADDR:  LDU     <USRSTK
FAF5-33 4A           909 ( 1)         LEAU    $0A,U           ; Point to user PC
FAF7-20 F5           910 ( 3)         BRA     ADDR1
FAF9-10 9E AA        911 ( 6) RADDR:  LDY     <USRSTK         ; Get address off 'CC' register
FAFC-CE E3 AC        912 ( 3) RADDR1: LDU     #TEMP           ; Dummy location for new value
FAFF-20 30           913 ( 3)         BRA     GDATA
FB01-CE E3 93        914 ( 3) MEM:    LDU     #MSAV           ; Point to memory address store
FB04-10 AE C4        915 ( 7)         LDY     ,U              ; Get initial value
FB07-5F              916 ( 2)         CLRB                    ; Set status zero
FB08-17 FD 74        917 ( 9) SPACEA: LBSR    CONCHR          ; Get input
FB0B-27 0B           918 ( 3)         BEQ     CRA             ; No address given
FB0D-8E FA B7        919 ( 3)         LDX     #MTABA          ; Search address table
FB10-16 FE 93        920 (55)         LBRA    DISPCH
FB13-5D              921 ( 2) CRD:    TSTB                    ; If status
FB14-2F 02           922 ( 3)         BLE     CRA             ; -1 or 0 then no change
FB16-31 21           923 ( 1)         LEAY    $01,Y           ; else up one
FB18-1F 21           924 ( 7) CRA:    TFR     Y,X             ; Print out address
FB1A-17 FF 58        925 ( 9)         LBSR    OPXREG
FB1D-A6 84           926 ( 5)         LDA     ,X              ; then data
FB1F-17 FF 75        927 ( 9)         LBSR    OPARSP
FB22-C6 01           928 ( 2)         LDB     #$01            ; Set status +1
FB24-D7 A1           929 ( 4)         STB     <ONLINE         ; Allow next line
FB26-20 09           930 ( 3)         BRA     GDATA           ; and continue
FB28-97 A2           931 ( 4) NOTA:   STA     <LASTC          ; Save for re-use
FB2A-8D 40           932 ( 7)         BSR     NUMB            ; Get number with
FB2C-29 38           933 ( 3)         BVS     MERR            ; error if none
FB2E-1F 02           934 ( 7)         TFR     D,Y             ; is new address
FB30-5F              935 ( 2) DAT1:   CLRB                    ; Set status 0
FB31-                936      COMMAA: .EQ     $
FB31-                937      SPACEB: .EQ     $
FB31-17 FD 4B        938 ( 9) GDATA:  LBSR    CONCHR          ; Get input
FB34-27 DD           939 ( 3)         BEQ     CRD             ; No data found CR
FB36-8E FA D3        940 ( 3)         LDX     #MTABAE         ; else search data table
FB39-16 FE 6A        941 (55)         LBRA    DISPCH
FB3C-5D              942 ( 2) SEMICB: TSTB                    ; Test status
FB3D-2C 02           943 ( 3)         BGE     SEMICA          ; If -1 then
FB3F-31 3F           944 ( 1)         LEAY    -1,Y            ; dec before
FB41-10 AF C4        945 ( 7) SEMICA: STY     ,U              ; Save new address
FB44-39              946 ( 5)         RTS                     ; and exit
FB45-                947      MINUSA: .EQ     $
FB45-31 3F           948 ( 1) MINUSB: LEAY    -1,Y            ; Back down 1,
FB47-5D              949 ( 2)         TSTB                    ; but if status
FB48-2C 02           950 ( 3)         BGE     MIND2           ; is -1 then
FB4A-31 3F           951 ( 1)         LEAY    -1,Y            ; duck down 2
FB4C-20 E2           952 ( 3) MIND2:  BRA     DAT1            ; then continue
FB4E-97 A2           953 ( 4) NOTB:   STA     <LASTC          ; Save for re-use
FB50-8D 1A           954 ( 7)         BSR     NUMB            ; in number.
FB52-29 12           955 ( 3)         BVS     MERR            ; Should have number
FB54-E7 A4           956 ( 5)         STB     ,Y              ; Store data then
FB56-E1 A4           957 ( 5)         CMPB    ,Y              ; check it
FB58-27 06           958 ( 3)         BEQ     COMMAB          ; is ok,
FB5A-8E FF 8F        959 ( 3)         LDX     #MQRY           ; else tell
FB5D-17 FD 8C        960 ( 9)         LBSR    STRING          ; user.
FB60-31 21           961 ( 1) COMMAB: LEAY    1,Y             ; Go up 1
FB62-C6 FF           962 ( 2)         LDB     #$FF            ; with status -1
FB64-20 CB           963 ( 3)         BRA     GDATA           ; then continue
FB66-17 FD 16        964 ( 9) MERR:   LBSR    CONCHR          ; Get wrong symbol
FB69-16 01 1D        965 (55)         LBRA    BADCMD          ; and tell user
FB6C-                966      ;
FB6C-                967      ; Get hex number from input stream, allow leading spaces and stop on first non-hex character,
FB6C-                968      ; return number in D, with V=0, if no number then do and V=1
FB6C-                969      ;
FB6C-                970              .DP     0
FB6C-4F              971 ( 2) NUMB:   CLRA
FB6D-5F              972 ( 2)         CLRB
FB6E-34 06           973 ( 7)         PSHS    D               ; Put initial zero value
FB70-8D 18           974 ( 7)         BSR     GETHXS          ; Get first non-blank as hex value
FB72-29 14           975 ( 3)         BVS     NUMB1           ; wasn't hex
FB74-C6 04           976 ( 2) NUMB3:  LDB     #$04
FB76-48              977 ( 2)         ASLA                    ; Move to
FB77-48              978 ( 2)         ASLA
FB78-48              979 ( 2)         ASLA
FB79-48              980 ( 2)         ASLA                    ; high nibble
FB7A-48              981 ( 2) NUMB2:  ASLA                    ; Rotate into
FB7B-69 61           982 ( 8)         ROL     1,S
FB7D-                983      ;
FB7D-                984              .DO     VER=490
FB7D-69 60           985              .DB     $69,$60         ; 'ROL  0,S'
FB7F-                986              .FI
FB7F-                987      ;
FB7F-             S  988              .DO     VER=495
FB7F-             S  989              .DB     $69,$E4         ; 'ROL ,S'
FB7F-                990              .FI
FB7F-                991      ;
FB7F-5A              992 ( 2)         DECB                    ; Do 4 times.
FB80-26 F8           993 ( 3)         BNE     NUMB2           ; Get a hex digit from console
FB82-8D 11           994 ( 7)         BSR     GETHEX          ; Was hex so use,
FB84-28 EE           995 ( 3)         BVC     NUMB3           ; else finish with V clear
FB86-1C FD           996 ( 3) NUMB4:  ANDCC   #$FD            ; CLV
FB88-35 86           997 ( 9) NUMB1:  PULS    D,PC
FB8A-                998      ;
FB8A-                999      ; GETHXS - get a hex digit ignoring leading spaces
FB8A-               1000      ; GETHEX - get a hex digit both return value in A, with V=0, else set V=1 if non-hex
FB8A-               1001      ;
FB8A-17 FC F2       1002 ( 9) GETHXS: LBSR    CONCHR          ; Get input.
FB8D-27 22          1003 ( 3)         BEQ     GETH5           ; On CR, no number
FB8F-81 20          1004 ( 2)         CMPA    #SPACE          ; If space
FB91-27 F7          1005 ( 3)         BEQ     GETHXS          ; then ignore
FB93-20 05          1006 ( 3)         BRA     GETH2           ; Change to hex
FB95-               1007      ;
FB95-17 FC E7       1008 ( 9) GETHEX: LBSR    CONCHR          ; Get input
FB98-27 17          1009 ( 3)         BEQ     GETH5           ; On CR, no number
FB9A-81 30          1010 ( 2) GETH2:  CMPA    #'0'
FB9C-25 0C          1011 ( 3)         BCS     GETH1           ; Illegal hex
FB9E-81 39          1012 ( 2)         CMPA    #'9'
FBA0-23 14          1013 ( 3)         BLS     GETH3           ; Number hex
FBA2-81 41          1014 ( 2)         CMPA    #'A'
FBA4-25 04          1015 ( 3)         BCS     GETH1           ; Illegal hex
FBA6-81 46          1016 ( 2)         CMPA    #'F'
FBA8-23 0A          1017 ( 3)         BLS     GETH4           ; Alpha hex
FBAA-81 2C          1018 ( 2) GETH1:  CMPA    #COMMA
FBAC-27 03          1019 ( 3)         BEQ     GETH5           ; Absorb comma
FBAE-B7 E3 A2       1020 ( 5)         STA     LASTC           ; else re-use
FBB1-1A 02          1021 ( 3) GETH5:  ORCC    #$02            ; Bad hex, SEV
FBB3-39             1022 ( 5)         RTS
FBB4-80 07          1023 ( 2) GETH4:  SUBA    #7              ; Alpha offset
FBB6-80 30          1024 ( 2) GETH3:  SUBA    #'0'            ; Number offset
FBB8-39             1025 ( 5)         RTS                     ; with V clear
FBB9-               1026      ;
FBB9-               1027      ; Resume user program using stack as stands
FBB9-               1028      ;
FBB9-               1029              .DP     MONDP
FBB9-32 62          1030 ( 1) RESUME: LEAS    2,S             ; Strip return address
FBBB-8D AF          1031 ( 7)         BSR     NUMB            ; Get number or zero
FBBD-DD A5          1032 ( 5)         STD     <NBREAK         ; and set break ignore count
FBBF-8D 6C          1033 ( 7) RES2:   BSR     BRKIN           ; Insert breakpoints
FBC1-35 FF          1034 (17)                 PULS    PC,U,Y,X,DP,B,A,CC      ; and pull all user registers off stack
FBC3-               1035      ;
FBC3-               1036      ; Software interrupt handler, come here on breakpoint
FBC3-               1037      ; Either stops and displays registers or traces past breakpoint and resumes
FBC3-               1038      ;
FBC3-86 E3          1039 ( 2) SWIHAN: LDA     #MONDP          ; Set up
FBC5-1F 8B          1040 ( 7)         TFR     A,DP            ; direct page
FBC7-               1041              .DP     MONDP
FBC7-AE 6A          1042 ( 7)         LDX     10,S            ; back up
FBC9-30 1F          1043 ( 1)         LEAX    -1,X            ; user
FBCB-AF 6A          1044 ( 7)         STX     10,S            ; program counter
FBCD-8D 77          1045 ( 7)         BSR     BRKOUT          ; remove breakpoint
FBCF-9E A5          1046 ( 5)         LDX     <NBREAK         ; Get count.
FBD1-27 08          1047 ( 3)         BEQ     RES1            ; stop if zero, else
FBD3-30 1F          1048 ( 1)         LEAX    -1,X            ; decrement
FBD5-9F A5          1049 ( 5)         STX     <NBREAK         ; and restore
FBD7-8D 76          1050 ( 7)         BSR     TUSER1          ; Trace past break
FBD9-20 E4          1051 ( 3)         BRA     RES2            ; then resume again
FBDB-10 DF AA       1052 ( 6) RES1:   STS     <USRSTK
FBDE-17 FC D7       1053 ( 9)         LBSR    EXREG           ; display registers
FBE1-20 19          1054 ( 3)         BRA     BACK1           ; and stay in monitor
FBE3-               1055      ;
FBE3-               1056      ; Change number in X if one given in input stream, destroys D
FBE3-               1057      ;
FBE3-8D 87          1058 ( 7) NUMBX:  BSR     NUMB
FBE5-29 02          1059 ( 3)         BVS     NUMBX1          ; No number
FBE7-1F 01          1060 ( 7)         TFR     D,X
FBE9-39             1061 ( 5) NUMBX1: RTS
FBEA-               1062      ;
FBEA-               1063      ; User program returns here if RTS done.
FBEA-               1064      ;
FBEA-32 7E          1065 ( 1) BACK:   LEAS    -2,S            ; Make room for new return address
FBEC-34 FF          1066 (17)         PSHS    CC,A,B,DP,X,Y,U,PC      ; and save all user registers
FBEE-8E FB EA       1067 ( 3)         LDX     #BACK           ; Set return address
FBF1-AF 6C          1068 ( 7)         STX     12,S            ; again
FBF3-C6 E3          1069 ( 2)         LDB     #MONDP
FBF5-1F 9B          1070 ( 7)         TFR     B,DP
FBF7-8D 4D          1071 ( 7)         BSR     BRKOUT          ; Remove breakpoints
FBF9-10 DF AA       1072 ( 6)         STS     <USRSTK         ; Save user stack pointer
FBFC-1C EF          1073 ( 3) BACK1:  ANDCC   #$EF            ; CLI: enable interrupts
FBFE-16 FC 59       1074 (55)         LBRA    PARSE           ; and resume monitor functions
FC01-               1075      ;
FC01-               1076      ; Go to user program, optional address specified
FC01-               1077      ; The stack pointer is reset, but the register contents are maintained as listed by the command
FC01-               1078
FC01-0F A5          1079 ( 6) GOUSER: CLR     <NBREAK+0       ; Put zero in
FC03-0F A6          1080 ( 6)         CLR     <NBREAK+1       ; break count
FC05-DE 5B          1081 ( 5)         LDU     <ISTACK         ; Get pointer
FC07-8E FB EA       1082 ( 3)         LDX     #BACK           ; return address,
FC0A-AF C3          1083 ( 9)         STX     ,--U            ; pushed first
FC0C-C6 0D          1084 ( 2)         LDB     #11+2           ; 12 registers plus return.
FC0E-A6 E5          1085 ( 6) GO1:    LDA     B,S             ; Get value and
FC10-A7 C2          1086 ( 7)         STA     ,-U             ; push it
FC12-5A             1087 ( 2)         DECB
FC13-2A F9          1088 ( 3)         BPL     GO1             ; For all registers
FC15-32 42          1089 ( 1)         LEAS    2,U             ; new stack, ignore return address
FC17-9E 95          1090 ( 5)         LDX     <GSAV           ; Saved address
FC19-8D C8          1091 ( 7)         BSR     NUMBX           ; Change if given
FC1B-9F 95          1092 ( 5)         STX     <GSAV           ; and restore.
FC1D-AF 6A          1093 ( 7)         STX     10,S            ; Put as user PC
FC1F-8D 0C          1094 ( 7)         BSR     BRKIN           ; Insert breakpoint
FC21-35 FF          1095 (17)         PULS    CC,A,B,DP,X,Y,U,PC      ; and begin user program
FC23-               1096      ;
FC23-               1097      ; Change user breakpoint position.
FC23-               1098      ;
FC23-8D 21          1099 ( 7) BRKSET  BSR     BRKOUT          ; Ensure old is out
FC25-8E FF FF       1100 ( 3)         LDX     #$FFFF          ; value for no break
FC28-8D B9          1101 ( 7)         BSR     NUMBX           ; change if given
FC2A-9F A3          1102 ( 5)         STX     <CBREAK         ; and save.
FC2C-39             1103 ( 5)         RTS
FC2D-               1104      ;
FC2D-               1105      ; Put breakpoint in if one exists.
FC2D-               1106      ;
FC2D-8D 09          1107 ( 7) BRKIN:  BSR     BRKTST          ; See if exists
FC2F-27 06          1108 ( 3)         BEQ     BRK1            ; Already a SWI, so done
FC31-97 A7          1109 ( 4)         STA     <CINST          ; else save it
FC33-86 3F          1110 ( 2)         LDA     #SWIOP
FC35-A7 84          1111 ( 5)         STA     ,X              ; and insert a SWI instead
FC37-39             1112 ( 5) BRK1:   RTS
FC38-               1113      ;
FC38-               1114      ; Check break required, if not does RTS twice.
FC38-               1115      ;
FC38-9E A3          1116 ( 5) BRKTST: LDX     <CBREAK         ; Get address
FC3A-8C FF FF       1117 ( 4)         CMPX    #$FFFF          ; $FFFF means none
FC3D-27 05          1118 ( 3)         BEQ     BRK10           ; not one
FC3F-A6 84          1119 ( 5)         LDA     ,X              ; Get instruction
FC41-81 3F          1120 ( 2)         CMPA    #SWIOP          ; see if SWI
FC43-39             1121 ( 5)         RTS                     ; then exit
FC44-35 90          1122 ( 9) BRK10:  PULS    PC,X            ; Exit twice
FC46-               1123      ;
FC46-               1124      ; Called by SWI
FC46-               1125      ; -------------
FC46-               1126      ; Remove a breakpoint if one present in code
FC46-               1127      ;
FC46-8D F0          1128 ( 7) BRKOUT: BSR     BRKTST          ; See if exists
FC48-26 04          1129 ( 3)         BNE     BRK2            ; Not SWI, leave alone
FC4A-96 A7          1130 ( 4)         LDA     <CINST          ; Get saved instruction
FC4C-A7 84          1131 ( 5)         STA     ,X              ; and restore in code
FC4E-39             1132 ( 5) BRK2:   RTS
FC4F-               1133      ;
FC4F-               1134      ; Trace one instruction of user code
FC4F-               1135      ;
FC4F-35 10          1136 ( 7) TUSER1: PULS    X               ; Get return address
FC51-9F 73          1137 ( 5)         STX     <IRQRTS         ; and save it
FC53-86 EF          1138 ( 2)         LDA     #255-IRQ        ; Clear IRQ mask
FC55-A4 E4          1139 ( 5)         ANDA    ,S              ; in user
FC57-A7 E4          1140 ( 5)         STA     ,S              ; condition codes
FC59-CC 0F 00       1141 ( 3)         LDD     #INTDEL         ; Delay before interrupt
FC5C-FD E9 84       1142 ( 6)         STD     KT1CL           ; Set timer going,
FC5F-35 FF          1143 (17)         PULS    CC,A,B,DP,X,Y,U,PC      ; start user program running
FC61-               1144      ;
FC61-               1145      ; Set number of instructions to trace on each command
FC61-               1146      ;
FC61-17 FF 08       1147 ( 9) TRACEN: LBSR    NUMB            ; Get 0 if no number
FC64-DD 5D          1148 ( 5)         STD     <NTRACE         ; Save result.
FC66-39             1149 ( 5) TRACE1: RTS
FC67-               1150      ;
FC67-               1151      ; Trace required number of instructions then display register contents and halt user
FC67-               1152      ;
FC67-9E 5D          1153 ( 5) TRACE:  LDX     <NTRACE         ; Get number to trace
FC69-27 FB          1154 ( 3)         BEQ     TRACE1          ; ignore command if zero
FC6B-32 62          1155 ( 1)         LEAS    2,S             ; strip return address
FC6D-9F A8          1156 ( 5) TRACE2: STX     <CTRACE         ; save number left
FC6F-8D DE          1157 ( 7)         BSR     TUSER1          ; trace one instruction
FC71-9E A8          1158 ( 5)         LDX     <CTRACE         ; Get number left
FC73-30 1F          1159 ( 1)         LEAX    -1,X            ; and decrement
FC75-26 F6          1160 ( 3)         BNE     TRACE2          ; repeat if required
FC77-16 FF 61       1161 (55)         LBRA    RES1            ; else show registers and halt user
FC7A-               1162      ;
FC7A-               1163      ; Turn printer echo of console output on or off
FC7A-               1164      ;
FC7A-17 FC 02       1165 ( 9) PCNTL:  LBSR    CONCHR          ; Get input
FC7D-27 06          1166 ( 3)         BEQ     POFF            ; if CR then off
FC7F-81 2B          1167 ( 2)         CMPA    #'+'            ; if plus
FC81-27 03          1168 ( 3)         BEQ     PON             ; then switch on
FC83-97 A2          1169 ( 4)         STA     <LASTC          ; Re-use if not +
FC85-4F             1170 ( 2) POFF:   CLRA                    ; Switch off value
FC86-97 61          1171 ( 4) PON:    STA     <PFLAG          ; Set flag
FC88-39             1172 ( 5)         RTS
FC89-               1173      ;
FC89-               1174      ; If get bad command, query it and ignore rest of line
FC89-               1175      ;
FC89-9E 75          1176 ( 5) BADCMD: LDX     <LINEPT         ; If memory input
FC8B-10 26 FC 18    1177 (5+)         LBNE    MEND            ; then exit
FC8F-8E FF C3       1178 ( 3)         LDX     #CQRY           ; Output query
FC92-17 FC 57       1179 ( 9)         LBSR    STRING          ; message
FC95-17 FD 89       1180 ( 9)         LBSR    CONOUT          ; and character
FC98-17 FC 4E       1181 ( 9)         LBSR    OPCRLF          ; followed by CR, LF
FC9B-17 FB E1       1182 ( 9) BAD1:   LBSR    CONCHR          ; Get input and
FC9E-26 FB          1183 ( 3)         BNE     BAD1            ; if not CR then ignore it
FCA0-39             1184 ( 5)         RTS                     ; then carry on
FCA1-               1185      ;
FCA1-               1186      ; Cassette file load routine, this searches for named file followed by data
FCA1-               1187      ;
FCA1-17 00 D1       1188 ( 9) LOAD:   LBSR    NAMEIN          ; Get file name
FCA4-17 FE C5       1189 ( 9)         LBSR    NUMB            ; Get offset
FCA7-DD 85          1190 ( 5)         STD     <OFFSET         ; and save
FCA9-8E E3 97       1191 ( 3) LOAD2:  LDX     #NAME           ; Point to filename space
FCAC-86 30          1192 ( 2) LOAD4:  LDA     #'0'            ; Get name file
FCAE-8D 4E          1193 ( 7)         BSR     GETHDR          ; header.
FCB0-26 FA          1194 ( 3)         BNE     LOAD4           ; Ignore others
FCB2-C6 06          1195 ( 2)         LDB     #$06            ; Name length
FCB4-D7 AC          1196 ( 4)         STB     <TEMP           ; Save it
FCB6-8D 66          1197 ( 7) LOAD3:  BSR     CBIN1           ; Get input character
FCB8-E6 80          1198 ( 7)         LDB     ,X+             ; and name character
FCBA-C1 3F          1199 ( 2)         CMPB    #'?'            ; If wildcard
FCBC-27 04          1200 ( 3)         BEQ     LOAD1           ; then matches
FCBE-A1 1F          1201 ( 6)         CMPA    -1,X            ; else compare
FCC0-26 E7          1202 ( 3)         BNE     LOAD2           ; Wrong name
FCC2-0A AC          1203 ( 6) LOAD1:  DEC     <TEMP           ; Count name length
FCC4-26 F0          1204 ( 3)         BNE     LOAD3           ; Repeat for all 6
FCC6-8D 56          1205 ( 7)         BSR     CBIN1           ; Ignore checksum byte
FCC8-               1206      ;
FCC8-               1207      ; Enter here for match without file name check
FCC8-               1208      ;
FCC8-86 31          1209 ( 2) LOAD7:  LDA     #'1'            ; Get data
FCCA-8D 32          1210 ( 7)         BSR     GETHDR          ; header
FCCC-26 24          1211 ( 3)         BNE     LOAD5           ; Wrong header
FCCE-8D 43          1212 ( 7)         BSR     CBIN2           ; Get start address
FCD0-1F 01          1213 ( 7)         TFR     D,X             ; and save while
FCD2-8D 3F          1214 ( 7)         BSR     CBIN2           ; getting end address
FCD4-34 06          1215 ( 7)                 PSHS    D       ; Put end on stack
FCD6-8D 46          1216 ( 7) LOAD6:  BSR     CBIN1           ; Get data item
FCD8-A7 80          1217 ( 7)         STA     ,X+             ; and store it
FCDA-AC E4          1218 ( 7)         CMPX    ,S              ; if not done
FCDC-23 F8          1219 ( 3)         BLS     LOAD6           ; then repeat
FCDE-8D 3E          1220 ( 7)         BSR     CBIN1           ; Get checksum byte
FCE0-35 10          1221 ( 7)         PULS    X               ; Get old end address
FCE2-17 FD 90       1222 ( 9)         LBSR    OPXREG          ; Show address so far
FCE5-1F 30          1223 ( 7)         TFR     U,D             ; check summed in U
FCE7-53             1224 ( 2)         COMB                    ; lower byte only
FCE8-27 DE          1225 ( 3)         BEQ     LOAD7           ; If ok, then repeat
FCEA-8E FF CD       1226 ( 3) LFCEA:  LDX     #LQRY           ; else message
FCED-17 FB FC       1227 ( 9)         LBSR    STRING          ; output
FCF0-20 04          1228 ( 3)         BRA     LKEYON
FCF2-81 39          1229 ( 2) LOAD5:  CMPA    #'9'            ; if not '9' then ignore
FCF4-26 D2          1230 ( 3)         BNE     LOAD7
FCF6-86 90          1231 ( 2) LKEYON: LDA     #CB1FLG+$80     ; Turn on keyboard
FCF8-B7 E9 8E       1232 ( 5)         STA     KIER
FCFB-16 FB EB       1233 (55)         LBRA    OPCRLF          ; then exit.
FCFE-               1234      ;
FCFE-               1235      ; Get a header from the tape, if the expected one then set zero status,
FCFE-               1236      ; else return non-zero status.  Initialises the checksum in U to 0
FCFE-               1237      ;
FCFE-34 02          1238 ( 6) GETHDR: PSHS    A               ; Save character
FD00-86 10          1239 ( 2)         LDA     #CB1FLG         ; Turn off keyboard
FD02-B7 E9 8E       1240 ( 5)         STA     KIER
FD05-8D 17          1241 ( 7) GETHD1: BSR     CBIN1           ; Get from tape
FD07-81 D8          1242 ( 2)         CMPA    #'X'+$80        ; and if not 'X' header marker
FD09-26 FA          1243 ( 3)         BNE     GETHD1          ; then try again
FD0B-8D 11          1244 ( 7)         BSR     CBIN1           ; Get next character
FD0D-CE 00 00       1245 ( 3)         LDU     #$0             ; Set up checksum
FD10-A1 E0          1246 ( 7)         CMPA    ,S+             ; and compare with required
FD12-39             1247 ( 5)         RTS                     ; then return
FD13-               1248      ;
FD13-               1249      ; Get 2 bytes and form a 16-bit value in D.  Add offset since is address
FD13-               1250      ;
FD13-8D 09          1251 ( 7) CBIN2:  BSR     CBIN1           ; Get 1 byte
FD15-1F 89          1252 ( 7)         TFR     A,B             ; and save while
FD17-8D 05          1253 ( 7)         BSR     CBIN1           ; get second
FD19-1E 89          1254 ( 7)         EXG     A,B             ; Wrong order, swap over
FD1B-D3 85          1255 ( 6)         ADDD    <OFFSET         ; Move by offset
FD1D-39             1256 ( 5)         RTS
FD1E-               1257      ;
FD1E-               1258      ; Get 1 byte from tape, modifying checksum to suit
FD1E-               1259      ;
FD1E-AD 9F E3 6B    1260 (13) CBIN1:  JSR     [CASINA]        ; Get byte then
FD22-33 C6          1261 ( 1)         LEAU    A,U             ; add to checksum
FD24-39             1262 ( 5)         RTS
FD25-               1263      ;
FD25-               1264      ; Software asynchronous transmitter, outputs value in A as a start bit, 8 data bits,
FD25-               1265      ; 2 stop bits, at rate controlled by count in DELCNT
FD25-               1266      ;
FD25-34 17          1267 (10) MCASOP: PSHS    CC,D,X          ; Saves all registers
FD27-1A 50          1268 ( 3)         ORCC    #$50            ; SEIF, Keep timing
FD29-C6 0B          1269 ( 2)         LDB     #11             ; Total length
FD2B-34 04          1270 ( 6)         PSHS    B               ; Save on stack
FD2D-C6 CF          1271 ( 2)         LDB     #IKPCR-COPBIT   ; Low start bit
FD2F-43             1272 ( 2)         COMA                    ; Want data inverted
FD30-12             1273 ( 2) MCAS01: NOP                     ; Get timing
FD31-20 00          1274 ( 3) LFD31:  BRA     MCAS02          ; constant
FD33-6A E4          1275 ( 7) MCAS02: DEC     ,S              ; Bits counter
FD35-2B 0E          1276 ( 3)         BMI     MCAS03          ; All done
FD37-F7 E9 8C       1277 ( 5)         STB     KPCR            ; Put out, but
FD3A-8D 0D          1278 ( 7)         BSR     CWAIT           ; wait 1 bit time
FD3C-C4 DF          1279 ( 2)         ANDB    #255-COPBIT     ; Assume next is zero
FD3E-44             1280 ( 2)         LSRA                    ; Get next bit
FD3F-25 EF          1281 ( 3)         BCS     MCAS01          ; Do want zero
FD41-CA 20          1282 ( 2)         ORB     #COPBIT         ; else set bit
FD43-20 EE          1283 ( 3)         BRA     MCAS02          ; and loop round
FD45-32 61          1284 ( 1) MCAS03: LEAS    1,S             ; Remove counter
FD47-35 97          1285 (12)         PULS    CC,D,X,PC       ; and return
FD49-               1286      ;
FD49-               1287      ; CWAIT waits for 1 bit time, destroys X
FD49-               1288      ; HWAIT waits 1/2 bit time, also destroys X
FD49-               1289      ;
FD49-               1290              .DP     0
FD49-8D 00          1291 ( 7) CWAIT:  BSR     HWAIT           ; Do first half
FD4B-BE E3 63       1292 ( 6) HWAIT:  LDX     DELCNT          ; Get count required
FD4E-30 1F          1293 ( 1) HW1:    LEAX    -1,X            ; Decrement
FD50-26 FC          1294 ( 3)         BNE     HW1             ; while non-zero
FD52-39             1295 ( 5)         RTS
FD53-               1296      ;
FD53-               1297      ; Software asynchronous receiver, gets value into A
FD53-               1298      ; Saves all other registers, only gets 1 stop bit
FD53-               1299      ;
FD53-               1300              .DP     MONDP
FD53-               1301      ;
FD53-               1302              .DO     VER=490
FD53-34 14          1303 ( 8) MCASIN: PSHS    B,X
FD55-86 80          1304 ( 2)         LDA     #$80            ; Rotating counter
FD57-F6 E9 80       1305 ( 5) MCAS11: LDB     KIRB            ; Wait for start bit
FD5A-2B FB          1306 ( 3) LFD5A:  BMI     MCAS11
FD5C-8D ED          1307 ( 7)         BSR     HWAIT           ; Wait 1/2 bit time
FD5E-F6 E9 80       1308 ( 5)         LDB     KIRB            ; Recheck
FD61-               1309              .FI
FD61-               1310      ;
FD61-             S 1311              .DO     VER=495
FD61-             S 1312      MCASIN: STX     <$A3            ; ??
FD61-             S 1313              ANDCC   #$EF
FD61-             S 1314      MCAS11: LDD     #MON
FD61-             S 1315              PSHS    A,B
FD61-             S 1316              JMP     BOOT
FD61-             S 1317              ADCB    ,X+
FD61-               1318              .FI
FD61-               1319      ;
FD61-2B F4          1320 ( 3)         BMI     MCAS11          ; start bit
FD63-8D E4          1321 ( 7) MCAS12: BSR     CWAIT           ; Wait whole bit time
FD65-F6 E9 80       1322 ( 5)         LDB     KIRB            ; and get input
FD68-AC E4          1323 ( 7)         CMPX    ,S              ; waste time to
FD6A-11 AC E4       1324 ( 8)         CMPS    ,S              ; match loop delays
FD6D-58             1325 ( 2)         LSLB                    ; Move bit to carry
FD6E-46             1326 ( 2)         RORA                    ; then into byte
FD6F-24 F2          1327 ( 3)         BCC     MCAS12          ; Repeat for 8 bits
FD71-8D D6          1328 ( 7)         BSR     CWAIT           ; Get into stop bit
FD73-35 94          1329 (10)         PULS    B,X,PC          ; and done
FD75-               1330      ;
FD75-               1331      ; Routine gets name from input stream, up to 6 characters long
FD75-               1332      ; No name leaves memory unaltered.  Any name is padded to 6 characters with spaces
FD75-               1333      ;
FD75-8E E3 9D       1334 ( 3) NAMEIN: LDX     #NAME+6
FD78-17 FB 04       1335 ( 9) NAM2:   LBSR    CONCHR          ; Get a character
FD7B-27 23          1336 ( 3)         BEQ     NAM1            ; no name
FD7D-81 20          1337 ( 2)         CMPA    #SPACE          ; if space
FD7F-27 F7          1338 ( 3)         BEQ     NAM2            ; ignore
FD81-81 2C          1339 ( 2)         CMPA    #COMMA
FD83-27 1B          1340 ( 3)         BEQ     NAM1            ; Null name
FD85-C6 FA          1341 ( 2)         LDB     #256-6          ; Minus name length
FD87-A7 85          1342 ( 6) NAM3:   STA     B,X             ; Store a letter
FD89-5C             1343 ( 2)         INCB                    ; and move up
FD8A-27 15          1344 ( 3)         BEQ     NAM6            ; Done 6 chars, exit
FD8C-17 FA F0       1345 ( 9)         LBSR    CONCHR          ; Get next letter
FD8F-27 08          1346 ( 3)         BEQ     NAM5            ; On CR, pad name
FD91-81 20          1347 ( 2)         CMPA    #SPACE          ; On space,
FD93-27 06          1348 ( 3)         BEQ     NAM4            ; pad name
FD95-81 2C          1349 ( 2)         CMPA    #COMMA          ; If not comma
FD97-26 EE          1350 ( 3)         BNE     NAM3            ; then use
FD99-86 20          1351 ( 2) NAM5:   LDA     #SPACE          ; padding
FD9B-A7 85          1352 ( 6) NAM4:   STA     B,X             ; Pad until
FD9D-5C             1353 ( 2)         INCB                    ; end of
FD9E-26 FB          1354 ( 3)         BNE     NAM4            ; name buffer
FDA0-39             1355 ( 5) NAM1:   RTS
FDA1-17 FA DB       1356 ( 9) NAM6:   LBSR    CONCHR          ; Get next input
FDA4-27 FA          1357 ( 3)         BEQ     NAM1            ; leave if CR
FDA6-81 2C          1358 ( 2)         CMPA    #COMMA          ; else
FDA8-27 F6          1359 ( 3) LFDA8:  BEQ     NAM1            ; absorb comma
FDAA-97 A2          1360 ( 4)         STA     <LASTC          ; else re-use
FDAC-39             1361 ( 5)         RTS
FDAD-               1362      ;
FDAD-               1363      ; Save files on cassette, dumps name block, data blocks as required in 256 byte blocks maximum,
FDAD-               1364      ; then end file block, can also inhibit end of file block
FDAD-               1365      ;
FDAD-9E 9D          1366 ( 5) SAVE:   LDX     <CSSTRT         ; Modify start address
FDAF-17 FE 31       1367 ( 9)         LBSR    NUMBX           ; if
FDB2-9F 9D          1368 ( 5)         STX     <CSSTRT         ; required
FDB4-9E 9F          1369 ( 5)         LDX     <CSEND          ; Modify end address
FDB6-17 FE 2A       1370 ( 9)         LBSR    NUMBX           ; if
FDB9-9F 9F          1371 ( 5)         STX     <CSEND          ; required
FDBB-8D B8          1372 ( 7)         BSR     NAMEIN          ; and get name
FDBD-C6 30          1373 ( 2)         LDB     #'0'            ; Output name,
FDBF-8D 3C          1374 ( 7)         BSR     XHEAD           ; header
FDC1-C6 06          1375 ( 2)         LDB     #6              ; name length
FDC3-30 1A          1376 ( 1)         LEAX    -6,X            ; Point to name,
FDC5-8D 46          1377 ( 7)         BSR     DATOUT          ; output name,
FDC7-8D 4E          1378 ( 7)         BSR     CHKOUT          ; then checksum.
FDC9-9E 9D          1379 ( 5)         LDX     <CSSTRT         ; Get start address
FDCB-34 10          1380 ( 7) SAV6:   PSHS    X               ; Save start
FDCD-DC 9F          1381 ( 5)         LDD     <CSEND          ; and get end address
FDCF-A3 E1          1382 (10)         SUBD    ,S++            ; Form length needed
FDD1-25 1D          1383 ( 3)         BLO     SAV2            ; Done all output
FDD3-4D             1384 ( 2)         TSTA                    ; If <=256 then
FDD4-27 03          1385 ( 3)         BEQ     SAV5            ; leave alone
FDD6-CC 00 FF       1386 ( 3)         LDD     #255            ; also set to 256
FDD9-33 8B          1387 ( 4) SAV5:   LEAU    D,X             ; Form end of block
FDDB-34 56          1388 (11)         PSHS    D,X,U           ; Put start/end on stack
FDDD-C6 31          1389 ( 2)         LDB     #'1'            ; Put a data
FDDF-8D 1C          1390 ( 7)         BSR     XHEAD           ; header.
FDE1-30 62          1391 ( 1)         LEAX    2,S             ; Point to start/end
FDE3-C6 04          1392 ( 2)         LDB     #4              ; Two words
FDE5-8D 26          1393 ( 7)         BSR     DATOUT          ; and put start/end out
FDE7-35 56          1394 (11)         PULS    D,X,U           ; Get all back
FDE9-5C             1395 ( 2)         INCB                    ; Modify length
FDEA-8D 21          1396 ( 7)         BSR     DATOUT          ; and send data bytes
FDEC-8D 29          1397 ( 7)         BSR     CHKOUT          ; then checksum
FDEE-20 DB          1398 ( 3)         BRA     SAV6            ; and repeat
FDF0-17 FA 8C       1399 ( 9) SAV2:   LBSR    CONCHR          ; Get input
FDF3-27 06          1400 ( 3)         BEQ     SAV3            ; On CR send of block
FDF5-81 2D          1401 ( 2)         CMPA    #'-'            ; If EOF inhibit
FDF7-27 1D          1402 ( 3)         BEQ     RTS1            ; then skip x9
FDF9-97 A2          1403 ( 4)         STA     <LASTC          ; Re-use input
FDFB-C6 39          1404 ( 2) SAV3    LDB     #'9'            ; Send EOF
FDFD-               1405      ;
FDFD-               1406      ; Routine to send header to block, header type in B.  Also initialises checksum in Y
FDFD-               1407      ;
FDFD-10 8E 00 00    1408 ( 4) XHEAD:  LDY     #0
FE01-31 3F          1409 ( 1) XH1:    LEAY    -1,Y            ; Loop
FE03-26 FC          1410 ( 3)         BNE     XH1             ; delay
FE05-86 D8          1411 ( 2)         LDA     #'X'+$80        ; Send an 'X' header marker
FE07-8D 13          1412 ( 7)         BSR     CASOPI          ; to cassette
FE09-1F 98          1413 ( 7)         TFR     B,A             ; Get type
FE0B-20 0F          1414 ( 3)         BRA     CASOPI          ; and send
FE0D-               1415      ;
FE0D-               1416      ; Data output routine, sends B databytes starting from X
FE0D-               1417      ; (B zero means 256 bytes), X moves up by B bytes
FE0D-               1418      ;
FE0D-A6 80          1419 ( 7) DATOUT: LDA     ,X+             ; Get data
FE0F-31 A6          1420 ( 1)         LEAY    A,Y             ; Modify checksum
FE11-8D 09          1421 ( 7)         BSR     CASOPI          ; Send data
FE13-5A             1422 ( 2)         DECB                    ; Repeat until
FE14-26 F7          1423 ( 3)         BNE     DATOUT          ; zero count
FE16-39             1424 ( 5) RTS1:   RTS
FE17-               1425      ;
FE17-               1426      ; Send checksum to tape from Y, lower byte only
FE17-               1427      ;
FE17-1F 20          1428 ( 7) CHKOUT: TFR      Y,D            ; Checksum to D
FE19-1F 98          1429 ( 7)         TFR      B,A            ; then get low byte
FE1B-43             1430 ( 2)         COMA                    ; Want result $FF
FE1C-6E 9F E3 69    1431 ( 9) CASOPI: JMP     [CASOPA]        ; Send check byte
FE20-               1432      ;
FE20-               1433      ; Drive parameter specification
FE20-               1434      ;
FE20-               1435      DISCIT:                                         ; Set up drive
FE20-35 04 0D 14 
     05 AA          1436              .DB     $35,4,$0D,$14,$05,$AA           ; For Shugart drive
FE26-35 04 10 FF 
     FF FF          1437              .DB     $35,4,DRIVE/$80*8+$10,$FF,$FF,$FF       ; Drive bad tracks
FE2C-7A 02 17 C1    1438              .DB     $3A+DRIVE,2,$17,$C1             ; Mode register setup
FE30-7A 02 23 68    1439              .DB     $3A+DRIVE,2,$23,$28+DRIVE       ; Load head onto disc, starts motor
FE34-6C 00          1440              .DB     $2C+DRIVE,0                     ; Query drive ready
FE36-69 01 00       1441              .DB     $29+DRIVE,1,0                   ; Seek to track 0
FE39-6C 00          1442              .DB     $2C+DRIVE,0                     ; Query drive ready
FE3B-               1443      ;
FE3B-               1444              .DO     VER=490
FE3B-53 03 00 02 
     21             1445              .DB     $13+DRIVE,3,$00,$02,$21         ; Read sector 2
FE40-               1446              .FI
FE40-               1447      ;
FE40-             S 1448              .DO     VER=495
FE40-             S 1449              .DB     $13+DRIVE,3,$00,$01,$21         ; Read sector 2
FE40-               1450              .FI
FE40-               1451      ;
FE40-53 02 00 03    1452              .DB     $13+DRIVE,2,$00,$03             ; Read starting at sector 3
FE44-               1453      ;
FE44-               1454      ; This routine bootstraps from a mini-floppy disc
FE44-               1455      ; Reads sector 2 to find where to put program
FE44-               1456      ;
FE44-8E FF 04       1457 ( 3) BOOT:   LDX     #ANRTI          ; Set dummy
FE47-9F 83          1458 ( 5)         STX     <INMI           ; interrupt routine
FE49-86 EA          1459 ( 2)         LDA     #FLOPY/256      ; Set direct page
FE4B-1F 8B          1460 ( 7)         TFR     A,DP            ; to floppy controller
FE4D-               1461              .DP     FLOPY/256       ; and tell assembler
FE4D-8E FE 20       1462 ( 3)         LDX     #DISCIT         ; Point to tables
FE50-8D 4D          1463 ( 7)         BSR     CMDPAR          ; Set drive parameters
FE52-8D 4B          1464 ( 7)         BSR     CMDPAR          ; Set bad tracks
FE54-8D 49          1465 ( 7)         BSR     CMDPAR          ; Set mode register
FE56-8D 47          1466 ( 7)         BSR     CMDPAR          ; Load head, drive on
FE58-8D 5C          1467 ( 7)         BSR     DRVRDY          ; Check drive ready
FE5A-8D 43          1468 ( 7)         BSR     CMDPAR          ; Seek track 0
FE5C-8D 58          1469 ( 7)         BSR     DRVRDY          ; Check drive ready
FE5E-8D 3F          1470 ( 7)         BSR     CMDPAR          ; Read sector 2
FE60-               1471      ;
FE60-               1472              .DO     VER=490
FE60-CE 00 00       1473 ( 3)         LDU     #$0000          ; Put at $0000
FE63-               1474              .FI
FE63-               1475      ;
FE63-             S 1476              .DO     VER=495
FE63-             S 1477              LDU     #$C000          ; Put at $C000
FE63-               1478              .FI
FE63-               1479      ;
FE63-1F 32          1480 ( 7)         TFR     U,Y             ; and point to it
FE65-8D 62          1481 ( 7)         BSR     TRNSFR          ; Move disc data to memory
FE67-               1482      ;
FE67-               1483              .DO     VER=490
FE67-26 2A          1484 ( 3)         BNE     DERR            ; Non-zero means error
FE69-CC FF 42       1485 ( 3)         LDD     #$FF42          ; Check first two bytes
FE6C-10 A3 A1       1486 (11)         CMPD    ,Y++            ; are $FF42
FE6F-26 22          1487 ( 3)         BNE     DERR            ; If not $FF42, no boot present
FE71-8D 2C          1488 ( 7)         BSR     CMDPAR          ; Start read at sector 3
FE73-EE A1          1489 ( 9)         LDU     ,Y++            ; Get address to put at
FE75-A6 A0          1490 ( 7)         LDA     ,Y+             ; and number of sectors
FE77-10 AE A4       1491 ( 7)         LDY     ,Y              ; Start of program
FE7A-8B 20          1492 ( 2)         ADDA    #$20            ; Add sector length value
FE7C-D6 00          1493 ( 4) BOOT1:  LDB     <FDCS           ; Get FDC status and
FE7E-C5 20          1494 ( 2)         BITB    #$20            ; if parameter register full
FE80-26 FA          1495 ( 3)         BNE     BOOT1           ; then wait
FE82-97 01          1496 ( 4)         STA     <FDCP           ; Send number of sectors
FE84-8D 43          1497 ( 7)         BSR     TRNSFR          ; Move data to memory
FE86-26 0B          1498 ( 3)         BNE     DERR            ; Error if non-zero
FE88-17 FC E1       1499 ( 9)         LBSR    NUMB            ; Try get number
FE8B-28 3B          1500 ( 3)         BVC     RTS2            ; Got one, stay in monitor
FE8D-10 FE E3 5B    1501 ( 7)         LDS     STACK           ; Reset stack and goto program
FE91-6E A4          1502 ( 4)         JMP     ,Y
FE93-8E FF CE       1503 ( 3) DERR:   LDX     #DQRY           ; Query user on display with error number
FE96-17 FA 53       1504 ( 9)         LBSR    STRING
FE99-17 FB E5       1505 ( 9)         LBSR    OPAREG
FE9C-16 FA 4A       1506 (55)         LBRA    OPCRLF          ; Newline and exit
FE9F-               1507              .FI
FE9F-               1508      ;
FE9F-             S 1509              .DO     VER=495
FE9F-             S 1510              BNE     DERR            ; Non-zero means error
FE9F-             S 1511              LDS     STACK           ; Reset stack and goto program
FE9F-             S 1512              JMP     $C000
FE9F-             S 1513      DERR:   LDX     #DQRY           ; Query user on display with error number
FE9F-             S 1514              LBSR    STRING
FE9F-             S 1515              LBSR    OPAREG
FE9F-             S 1516              LBRA    OPCRLF
FE9F-             S 1517              LDY     #CRTCSV
FE9F-             S 1518              LDX     #$E300
FE9F-             S 1519              LDB     #$0B
FE9F-             S 1520      LFE85:  LDA     ,Y+
FE9F-             S 1521              STA     ,X+
FE9F-             S 1522              DECB
FE9F-             S 1523              BPL     LFE85
FE9F-             S 1524              LDA     <$01
FE9F-             S 1525              DECA
FE9F-             S 1526              STA     ,X+
FE9F-             S 1527              CLRA
FE9F-             S 1528              LDB     <$01
FE9F-             S 1529              LSRB
FE9F-             S 1530              STD     ,X++
FE9F-             S 1531              RTS
FE9F-             S 1532              .DB     $FF,$FF,$FF,$FF,$FF,$FF,$FF     ; Packing
FE9F-               1533              .FI
FE9F-               1534      ;
FE9F-               1535      ; This routine sends one command followed by a variable number of parameters, possibly none
FE9F-               1536      ; X points to command, next byte is number of parameters
FE9F-               1537      ; X left pointing after last parameter, destroys D
FE9F-               1538      ;
FE9F-EC 81          1539 ( 9) CMDPAR: LDD     ,X++            ; Get command and number
FEA1-0D 00          1540 ( 6) CP1:    TST     <FDCS           ; Test status and
FEA3-2B FC          1541 ( 3)         BMI     CP1             ; wait if busy
FEA5-97 00          1542 ( 4)         STA     <FDCC           ; Send command
FEA7-5A             1543 ( 2) CP2:    DECB                    ; If no more parameters
FEA8-2B 1E          1544 ( 3)         BMI     RTS2            ; then exit
FEAA-96 00          1545 ( 4) CP4:    LDA     <FDCS           ; If parameter
FEAC-85 20          1546 ( 2)         BITA    #$20            ; register full
FEAE-26 FA          1547 ( 3)         BNE     CP4             ; then wait
FEB0-A6 80          1548 ( 7)         LDA     ,X+             ; Get parameter and
FEB2-97 01          1549 ( 4)         STA     <FDCP           ; send it
FEB4-20 F1          1550 ( 3)         BRA     CP2             ; then repeat
FEB6-               1551      ;
FEB6-               1552      ; Test if drive ready, on entry X points to read drive status command sequence,
FEB6-               1553      ; on exit drive is ready and X points to next command sequence
FEB6-               1554      ;
FEB6-1F 13          1555 ( 7) DRVRDY: TFR     X,U             ; Save pointer
FEB8-1F 31          1556 ( 7) DR2:    TFR     U,X             ; Restore pointer
FEBA-8D E3          1557 ( 7)         BSR     CMDPAR          ; Ask for drive status
FEBC-96 00          1558 ( 4) DR1:    LDA     <FDCS           ; Wait until
FEBE-85 10          1559 ( 2)         BITA    #$10            ; result
FEC0-27 FA          1560 ( 3)         BEQ     DR1             ; ready
FEC2-96 01          1561 ( 4)         LDA     <FDCR           ; Get result
FEC4-85 04          1562 ( 2)         BITA    #$04            ; Ready bit mask
FEC6-27 F0          1563 ( 3)         BEQ     DR2             ; Not ready, wait
FEC8-39             1564 ( 5) RTS2:   RTS
FEC9-               1565      ;
FEC9-34 01          1566 ( 6) TRNSFR: PSHS    CC              ; Save CC while
FECB-1A 50          1567 ( 3)         ORCC    #$50            ; SEIF, set masks, disc is on NMI
FECD-C6 04          1568 ( 2)         LDB     #$04            ; Data available mask
FECF-20 04          1569 ( 3)         BRA     TRN2
FED1-96 04          1570 ( 4) TRN1:   LDA     <FDCD           ; Get data
FED3-A7 C0          1571 ( 7)         STA     ,U+             ; and store it
FED5-3C FF          1572 (20) TRN2:   CWAI    #$FF            ; Wait for interrupt
FED7-D5 00          1573 ( 4)         BITB    <FDCS           ; Check data
FED9-26 F6          1574 ( 3)         BNE     TRN1            ; available
FEDB-35 01          1575 ( 6)         PULS    CC              ; Get interrupt masks back
FEDD-96 01          1576 ( 4)         LDA     <FDCR           ; then get result
FEDF-39             1577 ( 5)         RTS                     ; and return z bit accordingly
FEE0-               1578      ;
FEE0-               1579      ; Interrupt request handler, comes here on IRQ active
FEE0-               1580      ; Checks for timer 1 or keyboard interrupt, if neither then complains to user
FEE0-               1581      ;
FEE0-86 E3          1582 ( 2) IRQHAN: LDA     #MONDP          ; Set up
FEE2-1F 8B          1583 ( 7)         TFR     A,DP            ; direct page
FEE4-               1584              .DP     MONDP           ; tell assembler
FEE4-8E E9 80       1585 ( 3)         LDX     #KVIA           ; Point to VIA address
FEE7-A6 0D          1586 ( 6)         LDA     KIFR-KVIA,X     ; Get flag register
FEE9-2A 1A          1587 ( 3)         BPL     UNUSED          ; Not the VIA!
FEEB-84 40          1588 ( 2)         ANDA    #T1IFLG         ; Try timer 1
FEED-27 06          1589 ( 3)         BEQ     LFEF5           ; Not timer 1
FEEF-A7 0D          1590 ( 6)         STA     KIFR-KVIA,X     ; Clear the interrupt
FEF1-6E 9F E3 73    1591 ( 9)         JMP     [IRQRTS]
FEF5-A6 0D          1592 ( 6) LFEF5:  LDA     KIFR-KVIA,X     ; Get flags again
FEF7-84 10          1593 ( 2)         ANDA    #CB1FLG         ; Try for keyboard
FEF9-27 0A          1594 ( 3)         BEQ     UNUSED          ; Query user if not
FEFB-A7 0D          1595 ( 6)         STA     KIFR-KVIA,X     ; Clear the interrupt
FEFD-               1596      ;
FEFD-               1597              .DO     VER=490
FEFD-A6 00          1598              .DB     $A6,$00         ; 'LDA  KIRB-KVIA,X'    ; and get a character
FEFF-               1599              .FI
FEFF-               1600      ;
FEFF-             S 1601              .DO     VER=495
FEFF-             S 1602              .DB     $A6,$84         ; 'LDA ,X'
FEFF-               1603              .FI
FEFF-               1604      ;
FEFF-84 7F          1605 ( 2)         ANDA    #$7F            ; stripping spare bit
FF01-17 FA FF       1606 ( 9)         LBSR    HAVCHR          ; Put into buffer
FF04-3B             1607 (15) ANRTI:  RTI                     ; then leave IRQ level
FF05-               1608      ;
FF05-               1609      ; Come here if unused interrupts are active, so complain to user and stop processor
FF05-               1610      ; since cannot clear an unknown interrupt
FF05-               1611      ;
FF05-8E FF CC       1612 ( 3) UNUSED: LDX     #IERR           ; Query user on display
FF08-17 F9 E1       1613 ( 9)         LBSR    STRING
FF0B-20 FE          1614 ( 3) FOREVR: BRA     FOREVR          ; and stop dead !
FF0D-               1615      ;
FF0D-               1616                                      ; *** VDU Configurations ***
FF0D-               1617      ;
FF0D-               1618      ;       R0      Horizontal Total Register               horizontal frequency, the total number of characters displayed and non-displayed per line
FF0D-               1619      ;       R1      Horizontal Displayed Register           number of displayed characters per line
FF0D-               1620      ;       R2      Horizontal Sync Position Register       position (start) of the horizontal sync
FF0D-               1621      ;       R3      (Horizontal) Sync Width Register        bits 0-3: width (character clocks) of the horizontal sync pulse
FF0D-               1622      ;                                                       bits 4-7: vertical sync pulse width in scan line times
FF0D-               1623      ;       R4      Vertical Total Register                 determines the vertical frequency (in character line times-1)
FF0D-               1624      ;       R5      Vertical Total Adjust Register          adjustment to vertical frequency (in scan line times)
FF0D-               1625      ;       R6      Vertical Displayed Register             number of displayed character rows
FF0D-               1626      ;       R7      Vertical Sync Position Register         position of the vertical sync pulse (character row times)
FF0D-               1627      ;       R8      Interlace Mode Register                 bits 0,1 control the raster scan mode
FF0D-               1628      ;       R9      Maximum Scan Line Address Register      number of scan lines per character row - 1 (including spacing)
FF0D-               1629      ;       R10     Cursor Start Register                   bits 0-4 cursor start scan line
FF0D-               1630      ;                                                       bit 5 sets the blink frequency
FF0D-               1631      ;                                                       bit 6 blink enable
FF0D-               1632      ;       R11     Cursor End Register                     cursor end scan line
FF0D-               1633      ;
FF0D-               1634                                      ; 40-Column Configurations
FF0D-               1635      ;
FF0D-               1636              .DO     VDU=40          ; Original Acorn Monitor Configurations from Manual
FF0D-               1637      ;
FF0D-               1638                                      ; For S Version 6845 CRT Controller (Interlaced)
FF0D-3F             1639      CRTCSV: .DB     $3F             ; 64 characters per line (15,625kHz)
FF0E-28             1640              .DB     COLS            ; 40 displayed characters per line
FF0F-34             1641              .DB     $34             ; (52) start of horizontal sync - 52uS
FF10-44             1642              .DB     $44             ; bits 0-3: (4) width of horizontal sync pulse - 4uS
FF11-               1643                                      ; bits 4-7: (4) vertical sync pulse width - 256uS
FF11-1E             1644              .DB     $1E             ; (30) vertical frequency - 15.625kHz (31x10x64uS)
FF12-02             1645              .DB     $02             ; (2) adjustment to vertical frequency (2x64uS) giving a total of 19.968mS i.e. 50Hz (actually 50.08Hz)
FF13-19             1646              .DB     ROWS            ; 25 displayed character rows
FF14-1B             1647              .DB     $1B             ; (27) position of vertical sync pulse - 17.28mS
FF15-03             1648              .DB     $03             ; (3) Interlaced Sync and Video Mode
FF16-12             1649              .DB     $12             ; (18) 20 scan lines/character (10 interlaced)
FF17-70             1650              .DB     $70             ; bits 0-4: (16) cursor start scan line - 16
FF18-               1651                                      ; bit 5: (1) blink frequency - 1/32 of vertical field rate
FF18-               1652                                      ; bit 6: (1) blink enabled
FF18-13             1653              .DB     $13             ; bit 6: (19) underlined cursor
FF19-               1654      ;
FF19-               1655                                      ; For R Version 6845 CRT Controller (Non-Interlaced)
FF19-3F             1656      CRTCRV: .DB     $3F             ; 64 characters per line (15,625kHz)
FF1A-28             1657              .DB     COLS            ; 40 displayed characters per line
FF1B-34             1658              .DB     $34             ; (52) start of horizontal sync - 52uS
FF1C-04             1659              .DB     $04             ; bits 0-3: (0) width of horizontal sync pulse - 0uS
FF1D-               1660                                      ; bits 4-7: (4) vertical sync pulse width - 256uS
FF1D-1E             1661              .DB     $1E             ; (30) vertical frequency - 15.625kHz (31x10x64uS)
FF1E-02             1662              .DB     $02             ; (2) adjustment to vertical frequency (2x64uS) giving a total of 19.968mS i.e. 50Hz (actually 50.08Hz)
FF1F-19             1663              .DB     ROWS            ; 25 displayed character rows
FF20-1B             1664              .DB     $1B             ; (27) position of vertical sync pulse - 17.28mS
FF21-00             1665              .DB     $00             ; (3) Normal Sync Mode (non-interlaced)
FF22-09             1666              .DB     $09             ; (9) 10 scan lines/character
FF23-68             1667              .DB     $68             ; bits 0-4: (8) cursor start scan line - 8
FF24-               1668                                      ; bit 5: (1) blink frequency - 1/32 of vertical field rate
FF24-               1669                                      ; bit 6: (1) blink enabled
FF24-09             1670              .DB     $09             ; bit 6: (9) underlined cursor
FF25-               1671      ;
FF25-               1672              .FI
FF25-               1673      ;
FF25-             S 1674              .DO     VDU=41          ; Alternative Configurations which match System COS/DOS40B
FF25-             S 1675      ;
FF25-             S 1676                                      ; For S Version 6845 CRT Controller (Interlaced)
FF25-             S 1677      CRTCSV: .DB     $3F             ; 64 characters per line (15,625kHz)
FF25-             S 1678              .DB     COLS            ; 40 displayed characters per line
FF25-             S 1679              .DB     $33             ; (51) start of horizontal sync - 51uS
FF25-             S 1680              .DB     $44             ; bits 0-3: (4) width of horizontal sync pulse - 4uS
FF25-             S 1681                                      ; bits 4-7: (4) vertical sync pulse width - 256uS
FF25-             S 1682              .DB     $1E             ; (30) vertical frequency - 15.625kHz (31x10x64uS)
FF25-             S 1683              .DB     $02             ; (2) adjustment to vertical frequency (2x64uS) giving a total of 19.968mS i.e. 50Hz (actually 50.08Hz)
FF25-             S 1684              .DB     ROWS            ; 25 displayed character rows
FF25-             S 1685              .DB     $1B             ; (27) position of vertical sync pulse - 17.28mS
FF25-             S 1686              .DB     $03             ; (3) Interlaced Sync and Video Mode
FF25-             S 1687              .DB     $12             ; (18) 20 scan lines/character (10 interlaced)
FF25-             S 1688              .DB     $72             ; bits 0-4: (18) cursor start scan line - 18
FF25-             S 1689                                      ; bit 5: (1) blink frequency - 1/32 of vertical field rate
FF25-             S 1690                                      ; bit 6: (1) blink enabled
FF25-             S 1691              .DB     $13             ; bit 6: (19) underlined cursor
FF25-             S 1692      ;
FF25-             S 1693                                      ; For R Version 6845 CRT Controller (Non-Interlaced)
FF25-             S 1694      CRTCRV: .DB     $3F             ; 64 characters per line (15,625kHz)
FF25-             S 1695              .DB     COLS            ; 40 displayed characters per line
FF25-             S 1696              .DB     $33             ; (51) start of horizontal sync - 51uS
FF25-             S 1697              .DB     $04             ; bits 0-3: (0) width of horizontal sync pulse - 0uS
FF25-             S 1698                                      ; bits 4-7: (4) vertical sync pulse width - 256uS
FF25-             S 1699              .DB     $1E             ; (30) vertical frequency - 15.625kHz (31x10x64uS)
FF25-             S 1700              .DB     $02             ; (2) adjustment to vertical frequency (2x64uS) giving a total of 19.968mS i.e. 50Hz (actually 50.08Hz)
FF25-             S 1701              .DB     ROWS            ; 25 displayed character rows
FF25-             S 1702              .DB     $1B             ; (27) position of vertical sync pulse - 17.28mS
FF25-             S 1703              .DB     $00             ; (3) Normal Sync Mode (non-interlaced)
FF25-             S 1704              .DB     $09             ; (9) 10 scan lines/character
FF25-             S 1705              .DB     $68             ; bits 0-4: (8) cursor start scan line - 8
FF25-             S 1706                                      ; bit 5: (1) blink frequency - 1/32 of vertical field rate
FF25-             S 1707                                      ; bit 6: (1) blink enabled
FF25-             S 1708              .DB     $09             ; bit 6: (9) underlined cursor
FF25-             S 1709      ;
FF25-               1710              .FI
FF25-               1711      ;
FF25-               1712                                      ; 80-Column Configurations
FF25-               1713
FF25-             S 1714              .DO     VDU=80          ; These configurations match the '41' config  (taken from System COS/DOS80B)
FF25-             S 1715      ;
FF25-             S 1716                                      ; For S Version 6845 CRT Controller (Interlaced)
FF25-             S 1717      CRTCSV: .DB     $7F     $3F             ; 64 characters per line (15,625kHz)
FF25-             S 1718              .DB     COLS            ; 40 displayed characters per line
FF25-             S 1719              .DB     $60     $33             ; (51) start of horizontal sync - 51uS
FF25-             S 1720              .DB     $28     $44             ; bits 0-3: (4) width of horizontal sync pulse - 4uS
FF25-             S 1721                                      ; bits 4-7: (4) vertical sync pulse width - 256uS
FF25-             S 1722              .DB     $1E             ; (30) vertical frequency - 15.625kHz (31x10x64uS)
FF25-             S 1723              .DB     $02             ; (2) adjustment to vertical frequency (2x64uS) giving a total of 19.968mS i.e. 50Hz (actually 50.08Hz)
FF25-             S 1724              .DB     ROWS            ; 25 displayed character rows
FF25-             S 1725              .DB     $1B             ; (27) position of vertical sync pulse - 17.28mS
FF25-             S 1726              .DB     $40     $03             ; (3) Interlaced Sync and Video Mode
FF25-             S 1727              .DB     $09     $12             ; (18) 20 scan lines/character (10 interlaced)
FF25-             S 1728              .DB     $68     $72             ; bits 0-4: (18) cursor start scan line - 18
FF25-             S 1729                                      ; bit 5: (1) blink frequency - 1/32 of vertical field rate
FF25-             S 1730                                      ; bit 6: (1) blink enabled
FF25-             S 1731              .DB     $09     $13             ; bit 6: (19) underlined cursor
FF25-             S 1732      ;
FF25-             S 1733                                      ; For R Version 6845 CRT Controller (Non-Interlaced)
FF25-             S 1734      CRTCRV: .DB     $7F     $3F             ; 64 characters per line (15,625kHz)
FF25-             S 1735              .DB     COLS            ; 40 displayed characters per line
FF25-             S 1736              .DB     $60     $33             ; (51) start of horizontal sync - 51uS
FF25-             S 1737              .DB     $28     $04             ; bits 0-3: (0) width of horizontal sync pulse - 0uS
FF25-             S 1738                                      ; bits 4-7: (4) vertical sync pulse width - 256uS
FF25-             S 1739              .DB     $1E             ; (30) vertical frequency - 15.625kHz (31x10x64uS)
FF25-             S 1740              .DB     $02             ; (2) adjustment to vertical frequency (2x64uS) giving a total of 19.968mS i.e. 50Hz (actually 50.08Hz)
FF25-             S 1741              .DB     ROWS            ; 25 displayed character rows
FF25-             S 1742              .DB     $1B             ; (27) position of vertical sync pulse - 17.28mS
FF25-             S 1743              .DB     $40     $00             ; (3) Normal Sync Mode (non-interlaced)
FF25-             S 1744              .DB     $09             ; (9) 10 scan lines/character
FF25-             S 1745              .DB     $68             ; bits 0-4: (8) cursor start scan line - 8
FF25-             S 1746                                      ; bit 5: (1) blink frequency - 1/32 of vertical field rate
FF25-             S 1747                                      ; bit 6: (1) blink enabled
FF25-             S 1748              .DB     $09             ; bit 6: (9) underlined cursor
FF25-             S 1749      ;
FF25-               1750              .FI
FF25-               1751      ;
FF25-               1752      ; Set up table 1, copied directly to RAM at RTAB1
FF25-               1753      ;
FF25-E3 5B          1754      PTAB1   .DW     ISTACK          ; Initial stack pointer
FF27-00 00          1755              .DW     0               ; Trace initially off
FF29-7F             1756              .DB     BSPACE          ; Character echoes on rubout
FF2A-FF             1757              .DB     $FF             ; Echo on, line buffer on
FF2B-00             1758              .DB     0               ; Printer off
FF2C-0A             1759              .DB     LF              ; Do not send line feeds, use CR only to printer
FF2D-00 CD          1760              .DW     BAUD            ; Initial baud rate for cassette
FF2F-F9 5B          1761              .DW     DISPLA          ; Console output
FF31-FA 5E          1762              .DW     GETCHR          ; Console input
FF33-FD 25          1763              .DW     MCASOP          ; Cassette output
FF35-FD 53          1764              .DW     MCASIN          ; Cassette input
FF37-FA 9D          1765              .DW     PRINT           ; Printer routine
FF39-FF 7F          1766              .DW     FUNCTS          ; Display function table
FF3B-FF 51          1767              .DW     CMNDS           ; Monitor command table
FF3D-FF 05          1768              .DW     UNUSED          ; Initial timer 1 routine
FF3F-00 00          1769              .DW     $0000           ; No memory interpret
FF41-FF 05          1770              .DW     UNUSED          ; Reserved vector
FF43-FF 05          1771              .DW     UNUSED          ; SWI3
FF45-FF 05          1772              .DW     UNUSED          ; SWI2
FF47-FF 05          1773              .DW     UNUSED          ; FIRQ
FF49-FE E0          1774              .DW     IRQHAN          ; IRQ
FF4B-FB C3          1775              .DW     SWIHAN          ; SWI
FF4D-FF 05          1776              .DW     UNUSED          ; NMI
FF4F-00 00          1777              .DW     $0000           ; Initial load offset
FF51-               1778      PTAB2:  .EQ     $               ; End of table
FF51-               1779      ;
FF51-               1780      ; This table contains the standard set of commands provided by the monitor
FF51-               1781      ;
FF51-0E             1782      CMNDS:  .DB     CMNDE-CMNDS/3-1 ; Number of entries
FF52-47             1783              .AS     'G'
FF53-FC B0          1784              .DW     GOUSER-CMNDS    ; Go to program
FF55-4D             1785              .AS     'M'
FF56-FB B0          1786              .DW     MEM-CMNDS       ; Memory examine
FF58-52             1787              .AS     'R'
FF59-F9 67          1788              .DW     EXREG-CMNDS     ; Examine registers
FF5B-50             1789              .AS     'P'
FF5C-FC 68          1790              .DW     RESUME-CMNDS    ; Proceed after break
FF5E-54             1791              .AS     'T'
FF5F-FD 10          1792              .DW     TRACEN-CMNDS    ; Set trace number
FF61-53             1793              .AS     'S'
FF62-FE 5C          1794              .DW     SAVE-CMNDS      ; Save on cassette
FF64-4C             1795              .AS     'L'
FF65-FD 50          1796              .DW     LOAD-CMNDS      ; Load from cassette
FF67-56             1797              .AS     'V'
FF68-FC D2          1798              .DW     BRKSET-CMNDS    ; Set break address
FF6A-44             1799              .AS     'D'
FF6B-FE F3          1800              .DW     BOOT-CMNDS      ; Disc bootstrap
FF6D-43             1801              .AS     'C'
FF6E-FD 29          1802              .DW     PCNTL-CMNDS     ; Copy to printer
FF70-20             1803              .DB     SPACE
FF71-FB 0C          1804              .DW     ANRTS-CMNDS     ; Ignore spaces
FF73-2C             1805              .DB     COMMA
FF74-FB 0C          1806              .DW     ANRTS-CMNDS     ; Ignore commas
FF76-2E             1807              .AS     '.'
FF77-FD 16          1808              .DW     TRACE-CMNDS     ; Do trace operation
FF79-46             1809              .AS     'F'
FF7A-FD 77          1810              .DW     LOAD7-CMNDS     ; Finish file load
FF7C-01             1811              .DB     1
FF7D-FD 38          1812              .DW     BADCMD-CMNDS    ; Default is query user
FF7F-               1813      CMNDE:  .EQ     $
FF7F-               1814      ;
FF7F-               1815      ; This table contains the standard functions provided by the VDU control programs
FF7F-               1816      ;
FF7F-               1817      FUNCTS:
FF7F-               1818              .DO     VER=490
FF7F-04             1819              .DB     FUNCTE-FUNCTS/3-1 ; Number of entries
FF80-               1820      ;
FF80-0D             1821              .DB     CR              ; Carriage return
FF81-FA 6D          1822              .DW     DOCR-FUNCTS
FF83-               1823      ;
FF83-0A             1824              .DB     LF              ; Linefeed
FF84-F9 F8          1825              .DW     DOLF-FUNCTS
FF86-               1826      ;
FF86-7F             1827              .DB     BSPACE          ; Backspace
FF87-FA 06          1828              .DW     DORUB-FUNCTS
FF89-               1829      ;
FF89-0C             1830              .DB     FFEED           ; Formfeed
FF8A-F9 A6          1831              .DW     CRTCI-FUNCTS
FF8C-               1832      ;
FF8C-01             1833              .DB     1
FF8D-F9 EA          1834              .DW     SIMCHR-FUNCTS   ; Default is display it
FF8F-               1835              .FI
FF8F-               1836      ;
FF8F-             S 1837              .DO     VER=495
FF8F-             S 1838              .DB     FUNCTE-FUNCTS/3 ; Number of entries
FF8F-             S 1839      ;
FF8F-             S 1840              .DB     CR              ; Carriage return
FF8F-             S 1841              .DW     DOCR-FUNCTS
FF8F-             S 1842      ;
FF8F-             S 1843              .DB     LF              ; Linefeed
FF8F-             S 1844              .DW     DOLF-FUNCTS
FF8F-             S 1845      ;
FF8F-             S 1846              .DB     $08             ; Backspace ??
FF8F-             S 1847              .DW     DORUB-FUNCTS
FF8F-             S 1848      ;
FF8F-             S 1849              .DB     $01             ; Formfeed
FF8F-             S 1850              .DW     $F9EA           ; CRTCI-FUNCTS  ; $F9EA ??
FF8F-             S 1851              .DB     1
FF8F-             S 1852              .DW     SIMCHR-FUNCTS   ; Default is display it
FF8F-               1853              .FI
FF8F-               1854      ;
FF8F-               1855      FUNCTE: .EQ     $
FF8F-               1856      ;
FF8F-               1857      ; This is the list of strings used by the monitor
FF8F-               1858      ;
FF8F-52 6F 6D 3F    1859      MQRY:   .AS     "Rom?"
FF93-0D 0A 00       1860      SCRLF:  .DB     CR,LF,0
FF96-43 43 20 20 
     41 20 20 42 
     20 44 50 20 
     20 20 20 58 
     20 20 20 20 
     59 20 20 20 
     20 55 20 20 
     20 50 43 20 
     20 20 20 53    1861      TITLES: .AS     "CC  A  B DP    X    Y    U   PC    S"
FFBA-0D 0A 00       1862              .DB     CR,LF,0
FFBD-0D 0A          1863      PCMESS: .DB     CR,LF
FFBF-50 43 5D       1864              .AS     "PC]"
FFC2-00             1865              .DB     0
FFC3-57 68 61 74 
     20 69 73 3A    1866      CQRY:   .AS     "What is:"
FFCB-00             1867              .DB     0
FFCC-49             1868      IERR:   .AS     'I'
FFCD-2D             1869      LQRY:   .AS     '-'
FFCE-45 72 72 20    1870      DQRY:   .AS     "Err "
FFD2-00             1871              .DB     0
FFD3-               1872      ;
FFD3-               1873      ; This is the set of indirect jumps to redirect the interrupt vector addresses
FFD3-               1874      ;
FFD3-6E 9F E3 77    1875 ( 9) RESVI:  JMP     [IRESV]
FFD7-6E 9F E3 79    1876 ( 9) SWI3I:  JMP     [ISWI3]
FFDB-6E 9F E3 7B    1877 ( 9) SWI2I:  JMP     [ISWI2]
FFDF-6E 9F E3 7D    1878 ( 9) FIRQI:  JMP     [IFIRQ]
FFE3-6E 9F E3 7F    1879 ( 9) IRQI:   JMP     [IIRQ]
FFE7-6E 9F E3 81    1880 ( 9) SWII:   JMP     [ISWI]
FFEB-6E 9F E3 83    1881 ( 9) NMII:   JMP     [INMI]
FFEF-               1882      ;
FFEF-               1883      ; The following hardware vectors reside in the top 16 bytes of memory
FFEF-               1884      ; when the monitor is in its standard position
FFEF-               1885      ;
FFEF-               1886              .DO     VER=490
FFEF-00             1887              .DB     $00
FFF0-             S 1888              .EL
FFF0-             S 1889              .DB     $FF
FFF0-               1890              .FI
FFF0-               1891      ;
FFF0-FF D3          1892              .DW     RESVI
FFF2-FF D7          1893              .DW     SWI3I
FFF4-FF DB          1894              .DW     SWI2I
FFF6-FF DF          1895              .DW     FIRQI
FFF8-FF E3          1896              .DW     IRQI
FFFA-FF E7          1897              .DW     SWII
FFFC-FF EB          1898              .DW     NMII
FFFE-F8 00          1899              .DW     RESET