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57 lines
1.5 KiB
Plaintext
57 lines
1.5 KiB
Plaintext
;Screen Control Assembly Lanuage Routines for Oric-1
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SUBROUTINE _SCREEN
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SMTEXT EQU $00 ;Default Text Screen
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SMWIDE EQU $FF ;Wide Text Screen (Undefined)
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;Set Screen Mode
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SETSCR: CMP #SMTEXT ;If Default Text Screen
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BEQ GETSCR ;Return Return 0
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LDA #$FF ;Else Return ERROR
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RTS
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;Else Return 0
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;Get Screen Mode
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GETSCR: LDA #0 ;Return 0 (Default Text Mode)
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RTS
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;Clear the Screen
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CLRSCR EQU $CC0A ;Basic CLS Routine (Atmos = $CCCE)
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;Move Cursor to Home Position
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CRSRHM: LDA #0 ;Set Args to 0,0
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TAY ;and Fall into SETPOS
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;Set Cursor Position
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SETPOS: CLC
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ADC #2 ;Add 2 to Column
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PHA ;and Save It
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INY ;Add 1 to Row
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TYA ;and Save It
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PHA
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LDA #0 ;Turn Cursor Off
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JSR $F7CB
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PLA ;Retrieve Row
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STA $0268 ;and Store in CURROW
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PLA ;Retrieve Column
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STA $0269 ;and Store in CURCOL
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JSR $F67D ;Recalculate Screen Pointers
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LDA #0 ;Turn Cursor On
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JMP $F7CB ;and Return
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;Get Cursor Position
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GETPOS: LDA $0269 ;Load Column from CURCOL
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SEC
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SBC #2 ;Subtract 2
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BPL GETPOY ;If Negative
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LDA #0 ;set to 0
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GETPOY: LDY $0268 ;Load Row from CURROW
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DEY ;and Subtract 1
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RTS
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;Get Screen Size
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GETSIZ: LDA #38 ;38 Columns (First 2 are Protected)
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LDY #27 ;27 Rows
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RTS
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