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cc65/libsrc/cbm610/kplot.s
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git-svn-id: svn://svn.cc65.org/cc65/trunk@3 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-05-28 13:40:48 +00:00

77 lines
1.2 KiB
ArmAsm

;
; Ullrich von Bassewitz, 28.09.1998
;
; PLOT routine for the 610.
;
.export k_plot
.importzp crtc
.include "zeropage.inc"
.proc k_plot
bcc set
ldx CURS_Y
ldy CURS_X
rts
set: stx CURS_Y
sty CURS_X
lda LineLSBTab,x
sta CharPtr
lda LineMSBTab,x
sta CharPtr+1
lda IndReg
pha
lda #$0F
sta IndReg
ldy #$00
clc
sei
sta (crtc),y
lda CharPtr
adc CURS_X
iny
sta (crtc),y
dey
lda #$0E
sta (crtc),y
iny
lda (crtc),y
and #$F8
sta sedt1
lda CharPtr+1
adc #$00
and #$07
ora sedt1
sta (crtc),y
cli
pla
sta IndReg
rts
.endproc
; -------------------------------------------------------------------------
; Low bytes of the start address of the screen lines
.rodata
LineLSBTab:
.byte $00,$50,$A0,$F0,$40,$90,$E0,$30
.byte $80,$D0,$20,$70,$C0,$10,$60,$B0
.byte $00,$50,$A0,$F0,$40,$90,$E0,$30
.byte $80
; -------------------------------------------------------------------------
; High bytes of the start address of the screen lines
LineMSBTab:
.byte $D0,$D0,$D0,$D0,$D1,$D1,$D1,$D2
.byte $D2,$D2,$D3,$D3,$D3,$D4,$D4,$D4
.byte $D5,$D5,$D5,$D5,$D6,$D6,$D6,$D7
.byte $D7