mirror of
https://github.com/bobbimanners/Applecorn.git
synced 2024-11-15 19:07:03 +00:00
507 lines
14 KiB
ArmAsm
507 lines
14 KiB
ArmAsm
* VDU.S
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****************************************************
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* Apple //e VDU Driver for 40/80 column mode (PAGE2)
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****************************************************
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*
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* 15-Aug-2021 Optimised address calculations and PRCHRC.
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* Entry point to move copy cursor.
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* Start to consolidate VDU workspace.
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* 16-Aug-2021 Added COPY cursor handling.
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**********************************
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* VDU DRIVER WORKSPACE LOCATIONS *
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**********************************
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* $00D0-$00DF VDU driver zero page workspace
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VDUSTATUS EQU $D0 ; $D0 VDU status
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VDUZP1 EQU VDUSTATUS+1 ; $D1
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* VDUTEXTX EQU VDUSTATUS+2 ; $D2 text column
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* VDUTEXTY EQU VDUSTATUS+3 ; $D3 text row
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VDUADDR EQU VDUSTATUS+4 ; $D4 address of current char cell
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FXVDUQLEN EQU $D1 ; TEMP HACK
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VDUCHAR EQU $D6 ; TEMP HACK
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VDUQ EQU $D7 ; TEMP HACK
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* VDUVARS
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* VDUTEXTX EQU $250+0 ; text X coord
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* VDUTEXTY EQU $250+1 ; text Y coord
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VDUTEXTX EQU COL
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VDUTEXTY EQU ROW
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VDUCOPYX EQU $250+2 ; copy cursor X coord
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VDUCOPYY EQU $250+3 ; copy cursor Y coord
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* VDUCOPYCHR EQU $260+0 ; char underneath cursor when copying
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* VDUCURSOR EQU $250+4 ; cursor character
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* VDUMODE EQU $250+5 ; current MODE
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* VDUCHAR EQU $250+6 ; VDU command, 1 byte
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* VDUQ EQU $250+7 ; VDU sequence, 9 bytes
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* KBD or VDU?
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* FLASHER ; flash counter for cursor
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* OLDCHAR ; character under cursor
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* CURSOR ; character used for cursor
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* Move editing cursor
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* A=cursor key, CS from caller
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COPYMOVE PHA
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BIT VDUSTATUS
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BVS COPYMOVE2 ; Edit cursor already on
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JSR GETCHRC
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STA COPYCHAR
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LDA CURSORED
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JSR PUTCHRC ; Edit cursor
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SEC
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JSR COPYSWAP2 ; Initialise copy cursor
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ROR FLASHER
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ASL FLASHER ; Ensure b0=0
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LDA #$42
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ORA VDUSTATUS
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STA VDUSTATUS ; Turn cursor editing on
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COPYMOVE2 PLA
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AND #3 ; Convert to 8/9/10/11
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ORA #8
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COPYMOVE3 JMP OUTCHARGO ; Move edit cursor
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;* Turn editing cursor on/off
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;COPYCURSOR BIT VDUSTATUS
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; BVC COPYSWAP4 ; Copy cursor not active
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; PHP ; Save CS=Turn On, CC=Turn Off
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; JSR COPYSWAP1 ; Swap to edit cursor
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; LDA COPYCHAR ; Prepare to turn edit cursor off
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; PLP
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; BCC COPYCURS2 ; Restore character
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;COPYCURS1 JSR GETCHRC ; Get character under edit cursor
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; STA COPYCHAR
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; LDA #$A0 ; Output edit cursor
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;COPYCURS2 JSR PUTCHRC
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;* ; Drop through to swap back
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* Swap between edit and copy cursors
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;COPYSWAP BIT VDUSTATUS
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; BVC COPYSWAP4 ; Edit cursor off
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COPYSWAP1 CLC ; CC=Swap TEXT and COPY
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COPYSWAP2 LDX #1
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COPYSWAPLP LDY VDUCOPYX,X
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LDA VDUTEXTX,X
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STA VDUCOPYX,X
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BCS COPYSWAP3 ; CS=Copy TEXT to COPY
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TYA
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STA VDUTEXTX,X
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COPYSWAP3 DEX
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BPL COPYSWAPLP
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COPYSWAP4 RTS
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* Clear to EOL
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CLREOL LDA ROW
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ASL
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TAX
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LDA SCNTAB,X ; LSB of row
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STA ZP1
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LDA SCNTAB+1,X ; MSB of row
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STA ZP1+1
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LDA COL
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PHA
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STZ COL
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:L1 LDA COL
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LSR
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TAY
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BCC :S1
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>>> WRTMAIN
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:S1 LDA #" "
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STA (ZP1),Y
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>>> WRTAUX
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LDA COL
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CMP #79
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BEQ :S2
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INC COL
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BRA :L1
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:S2 PLA
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STA COL
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RTS
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* Clear the screen
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VDUINIT STA $C00F
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LDA #'_'
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STA CURSOR
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LDA #$A0
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STA CURSORED
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CLEAR STZ ROW
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STZ COL
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:L1 JSR CLREOL
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:S2 LDA ROW
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CMP #23
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BEQ :S3
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INC ROW
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BRA :L1
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:S3 STZ ROW
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STZ COL
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RTS
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* Calculate character address
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CHARADDR LDA VDUTEXTY
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ASL
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TAX
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LDA SCNTAB+0,X ; LSB of row address
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STA VDUADDR+0
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LDA SCNTAB+1,X ; MSB of row address
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STA VDUADDR+1
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LDA VDUTEXTX
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BIT $C01F
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SEC
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BPL CHARADDR40 ; 40-col
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LSR A
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CHARADDR40 TAY ; Y=offset into this row
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RTS
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* (VDUADDR),Y=>character address
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* CC=auxmem
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* CS=mainmem
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* Print char in A at ROW,COL
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PRCHRC PHA ; Save character
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LDA $C000
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BPL :RESUME ; No key pressed
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EOR #$80
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:PAUSE1 JSR KBDESC ; Ask KBD to test if Escape
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BIT ESCFLAG
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BMI :RESUMEACK ; Escape, skip pausing
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CMP #$13
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BNE :RESUME ; Not Ctrl-S
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STA $C010 ; Ack. keypress
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:PAUSE2 LDA $C000
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BPL :PAUSE2 ; Loop until keypress
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EOR #$80
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CMP #$11 ; Ctrl-Q
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BEQ :RESUMEACK ; Stop pausing
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JSR KBDESC ; Ask KBD to test if Escape
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BIT ESCFLAG
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BPL :PAUSE2 ; No Escape, keep pausing
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:RESUMEACK STA $C010 ; Ack. keypress
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:RESUME PLA
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* Put character to screen
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PUTCHRC PHA
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PRCHR5 JSR CHARADDR ; Find character address
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PLA ; Get character back
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PHP ; Disable IRQs while
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SEI ; toggling memory
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BCC PRCHR6 ; Aux memory
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STA $C004 ; Switch to main memory
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PRCHR6 EOR #$80 ; Convert character
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STA (VDUADDR),Y ; Store it
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STA $C005 ; Back to aux memory
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PLP ; Restore IRQs
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RTS
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* PHA
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* LDA $C000 ; Kbd data/strobe
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* BMI :KEYHIT
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* :RESUME LDA ROW
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* ASL
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* TAX
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* LDA SCNTAB,X ; LSB of row address
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* STA ZP1
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* LDA SCNTAB+1,X ; MSB of row address
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* STA ZP1+1
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* LDA COL
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* BIT $C01F
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* BPL :S1A ; 40-col
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* LSR
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* BCC :S1
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*:S1A >>> WRTMAIN
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*:S1 TAY
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* PLA
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* EOR #$80
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* STA (ZP1),Y ; Screen address
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* >>> WRTAUX
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* RTS
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*:KEYHIT STA $C010 ; Clear strobe
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* AND #$7F
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* CMP #$13 ; Ctrl-S
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* BEQ :PAUSE
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* CMP #$1B ; Esc
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* BNE :RESUME
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*:ESC SEC
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* ROR ESCFLAG ; Set ESCFLAG
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* BRA :RESUME
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*:PAUSE STA $C010 ; Clear strobe
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*:L1 LDA $C000 ; Kbd data/strobe
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* BPL :L1
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* AND #$7F
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* CMP #$11 ; Ctrl-Q
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* BEQ :RESUME
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* CMP #$1B ; Esc
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* BEQ :ESC
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* BRA :PAUSE
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* Return char at ROW,COL in A and X, MODE in Y
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BYTE87
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GETCHRC JSR CHARADDR ; Find character address
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PHP ; Disable IRQs while
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SEI ; toggling memory
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BCC GETCHR6 ; Aux memory
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STA $C002 ; Switch to main memory
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GETCHR6 LDA (VDUADDR),Y ; Get character
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STA $C003 ; Back to aux memory
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PLP ; Restore IRQs
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EOR #$80 ; Convert character
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TAX ; X=char for OSBYTE
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LDY #$00
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BIT $C01F
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BMI GETCHROK
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INY ; Y=MODE
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GETCHROK RTS
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*GETCHRC LDA ROW
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* ASL
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* TAX
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* LDA SCNTAB,X
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* STA ZP1
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* LDA SCNTAB+1,X
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* STA ZP1+1
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* LDA COL
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* BIT $C01F
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* BPL :S1A ; 40-col
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* LSR
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* BCC :S1
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*:S1A STA $C002 ; Read main memory
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*:S1 TAY
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* LDA (ZP1),Y
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* EOR #$80
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* STA $C003 ; Read aux mem again
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* TAX
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* LDY #$00
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* BIT $C01F
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* BMI :GETCHOK
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* INY
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*:GETCHOK RTS
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BYTE86 LDY ROW ; $86 = read cursor pos
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LDX COL
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RTS
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* Perform backspace & delete operation
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DELETE JSR BACKSPC
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* LDA COL
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* BEQ :S1
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* DEC COL
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* BRA :S2
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*:S1 LDA ROW
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* BEQ :S3
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* DEC ROW
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* LDA #79
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* STA COL
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:S2 LDA #' '
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JMP PUTCHRC
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*:S3 RTS
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* Perform backspace/cursor left operation
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BACKSPC LDA COL
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BEQ :S1
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DEC COL
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BRA :S3
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:S1 LDA ROW
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BEQ :S3
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DEC ROW
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LDA #39
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BIT $C01F
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BPL :S2
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LDA #79
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:S2 STA COL
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:S3 RTS
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** Perform cursor right operation
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*CURSRT LDA COL
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* CMP #78
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* BCS :S1
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* INC COL
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* RTS
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*:S1 LDA ROW
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* CMP #22
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* BCS :S2
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* INC ROW
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* STZ COL
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*:S2 RTS
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* Output character to VDU driver
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* All registers trashable
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OUTCHAR
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*
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* Quick'n'nasty VDU queue
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LDX FXVDUQLEN
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BNE ADDTOQ
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CMP #$01
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BEQ ADDQ ; One param
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CMP #$11
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BCC OUTCHARGO ; Zero param
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CMP #$20
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BCS OUTCHARGO ; Print chars
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ADDQ STA VDUCHAR ; Save initial character
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AND #$0F
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TAX
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LDA QLEN,X
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STA FXVDUQLEN
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BEQ OUTCHARGO1
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QDONE RTS
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QLEN DB -0,-1,-2,-5,-0,-0,-1,-9
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DB -8,-5,-0,-0,-4,-4,-0,-2
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ADDTOQ STA VDUQ-256+9,X
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INC FXVDUQLEN
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BNE QDONE
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OUTCHARGO1 LDA VDUCHAR
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* end nasty hack
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*
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OUTCHARGO CMP #$00 ; NULL
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BNE :T1
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BRA :IDONE
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:T1 CMP #$07 ; BELL
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BNE :T2
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JSR BEEP
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BRA :IDONE
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:T2 CMP #$08 ; Backspace
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BNE :T3
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JSR BACKSPC
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BRA :IDONE
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:T3 CMP #$09 ; Cursor right
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BNE :T4
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* JSR CURSRT
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JSR VDU09
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BRA :IDONE
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:T4 CMP #$0A ; Linefeed
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BNE :T5
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LDA ROW
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CMP #23
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* BEQ SCROLL ; BOBBI
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BEQ :TOSCROLL ; JGH
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INC ROW
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:IDONE RTS
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; BRA :DONE
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:TOSCROLL JMP SCROLL ; JGH
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:T5 CMP #$0B ; Cursor up
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BNE :T6
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LDA ROW
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BEQ :IDONE
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DEC ROW
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; BRA :IDONE
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RTS
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:T6 CMP #$0D ; Carriage return
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BNE :T7
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LDA #$BF
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AND VDUSTATUS
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STA VDUSTATUS ; Turn copy cursor off
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STZ COL
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; BRA :IDONE
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RTS
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:T7 CMP #$0C ; Ctrl-L
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BEQ :T7A
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CMP #$16 ; MODE
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BNE :T8
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LDA VDUQ+8
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EOR #$07
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AND #$01
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TAX
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STA $C00C,X
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:T7A JSR CLEAR
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; BRA :IDONE
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RTS
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:T8 CMP #$1E ; Home
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BNE :T9
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STZ ROW
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STZ COL
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; BRA :IDONE
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RTS
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:T9
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CMP #$1F ; TAB
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BNE :T9B
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LDY VDUQ+8
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CPY #24
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BCS :IDONE
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LDX VDUQ+7
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CPX #80
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BCS :IDONE
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BIT $C01F
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BMI :T9A
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CPX #80
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BCS :IDONE
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:T9A STX COL
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STY ROW
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RTS
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:T9B CMP #$7F ; Delete
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BNE :T10
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JSR DELETE
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; BRA :IDONE
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RTS
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:T10 CMP #$20
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BCC :IDONE
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JSR PRCHRC ; Store char, checking keypress
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* Perform cursor right operation
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VDU09 LDA COL
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CMP #39
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BCC :S2
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BIT $C01F
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BPL :T11
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CMP #79
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BCC :S2
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:T11 STZ COL
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LDA ROW
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CMP #23
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BEQ SCROLL
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INC ROW
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:DONE RTS
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; BRA :DONE
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:S2 INC COL
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BRA :DONE
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SCROLL JSR SCROLLER
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* STZ COL
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JSR CLREOL
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;:DONE
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RTS
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* Scroll whole screen one line
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SCROLLER LDA #$00
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:L1 PHA
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JSR SCR1LINE
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PLA
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INC
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CMP #23
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BNE :L1
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RTS
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* Copy line A+1 to line A
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SCR1LINE ASL ; Dest addr->ZP1
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TAX
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LDA SCNTAB,X
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STA ZP1
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LDA SCNTAB+1,X
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STA ZP1+1
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INX ; Source addr->ZP2
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INX
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LDA SCNTAB,X
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STA ZP2
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LDA SCNTAB+1,X
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STA ZP2+1
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LDY #$00
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:L1 LDA (ZP2),Y
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STA (ZP1),Y
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STA $C002 ; Read main mem
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>>> WRTMAIN
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LDA (ZP2),Y
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STA (ZP1),Y
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STA $C003 ; Read aux mem
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>>> WRTAUX
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INY
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CPY #40
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BNE :L1
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RTS
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* Addresses of screen rows in PAGE2
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SCNTAB DW $800,$880,$900,$980,$A00,$A80,$B00,$B80
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DW $828,$8A8,$928,$9A8,$A28,$AA8,$B28,$BA8
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DW $850,$8D0,$950,$9D0,$A50,$AD0,$B50,$BD0
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