77 lines
846 B
ArmAsm
77 lines
846 B
ArmAsm
GBASL = $26
|
|
GBASH = $27
|
|
HGRPAGE = $E6
|
|
YPOS = $FE
|
|
COLOR = $FF
|
|
|
|
HGR = $F3E2
|
|
HGR2 = $F3D8
|
|
HPOSN = $F411
|
|
|
|
raster:
|
|
jsr HGR
|
|
jsr HGR2
|
|
; sta $C050 ; set graphics
|
|
; sta $C057 ; set hires
|
|
; sta $C052 ; set fullscreen
|
|
sta $C05E ; set double hires
|
|
sta $C00D ; 80 column
|
|
sta $C001 ; 80 store
|
|
|
|
lda #$20
|
|
sta HGRPAGE
|
|
|
|
lda #0
|
|
sta YPOS
|
|
color_loop:
|
|
lda YPOS
|
|
and #$f
|
|
sta COLOR
|
|
asl
|
|
asl
|
|
asl
|
|
asl
|
|
ora COLOR
|
|
sta COLOR
|
|
lda YPOS
|
|
jsr draw_line_color
|
|
|
|
inc YPOS
|
|
lda YPOS
|
|
cmp #192
|
|
bne color_loop
|
|
|
|
forever:
|
|
jmp forever
|
|
|
|
|
|
;=========================
|
|
; draw line of color in COLOR
|
|
;=========================
|
|
draw_line_color:
|
|
ldx #0
|
|
ldy #0
|
|
jsr HPOSN
|
|
|
|
ldy #0
|
|
loop_it:
|
|
; set page2
|
|
sta $C055
|
|
lda COLOR
|
|
sta (GBASL),Y
|
|
cmp #$80
|
|
rol COLOR
|
|
|
|
; set page1
|
|
sta $C054
|
|
lda COLOR
|
|
sta (GBASL),Y
|
|
cmp #$80
|
|
rol COLOR
|
|
iny
|
|
|
|
cpy #40
|
|
bne loop_it
|
|
|
|
rts
|