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6d498d8187
to emulate these functions on platforms where one or more of these functions are not available (PET, CBM-II). git-svn-id: svn://svn.cc65.org/cc65/trunk@1544 b7a2c559-68d2-44c3-8de9-860c34a00d81
77 lines
1.2 KiB
ArmAsm
77 lines
1.2 KiB
ArmAsm
;
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; Ullrich von Bassewitz, 28.09.1998
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;
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; PLOT routine for the 610.
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;
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.export PLOT
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.importzp crtc
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.include "cbm610.inc"
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.proc PLOT
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bcc set
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ldx CURS_Y
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ldy CURS_X
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rts
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set: stx CURS_Y
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sty CURS_X
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lda LineLSBTab,x
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sta CharPtr
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lda LineMSBTab,x
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sta CharPtr+1
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lda IndReg
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pha
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lda #$0F
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sta IndReg
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ldy #$00
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clc
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sei
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sta (crtc),y
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lda CharPtr
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adc CURS_X
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iny
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sta (crtc),y
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dey
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lda #$0E
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sta (crtc),y
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iny
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lda (crtc),y
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and #$F8
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sta sedt1
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lda CharPtr+1
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adc #$00
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and #$07
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ora sedt1
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sta (crtc),y
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cli
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pla
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sta IndReg
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rts
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.endproc
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; -------------------------------------------------------------------------
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; Low bytes of the start address of the screen lines
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.rodata
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LineLSBTab:
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.byte $00,$50,$A0,$F0,$40,$90,$E0,$30
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.byte $80,$D0,$20,$70,$C0,$10,$60,$B0
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.byte $00,$50,$A0,$F0,$40,$90,$E0,$30
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.byte $80
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; -------------------------------------------------------------------------
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; High bytes of the start address of the screen lines
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LineMSBTab:
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.byte $D0,$D0,$D0,$D0,$D1,$D1,$D1,$D2
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.byte $D2,$D2,$D3,$D3,$D3,$D4,$D4,$D4
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.byte $D5,$D5,$D5,$D5,$D6,$D6,$D6,$D7
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.byte $D7
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