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 outer_loop: lda #0 sta YPOS color_loop: lda #$22 inc COLOR lda YPOS jsr draw_line_color inc YPOS lda YPOS cmp #192 bne color_loop forever: jmp outer_loop ;============================= ; draw line of color in COLOR ;============================= draw_line_color: ldx #0 ldy #0 jsr HPOSN ldy #39 loop_it: ; set page2 sta $C055 jsr next_pixel ; set page1 sta $C054 jsr next_pixel dey bpl loop_it rts next_pixel: lda COLOR ; 2 sta (GBASL),Y ; 3 cmp #$80 ; 2 rol COLOR ; 2 rts ; 1