GBASL = $26 GBASH = $27 HGRPAGE = $E6 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 COLOR lda #100 jsr draw_line_color lda #$4 sta COLOR lda #99 jsr draw_line_color lda #$4 sta COLOR lda #101 jsr draw_line_color lda #$8 sta COLOR lda #98 jsr draw_line_color lda #$8 sta COLOR lda #102 jsr draw_line_color forever: jmp forever ;========================= ; draw line of color in COLOR ; at location A ;========================= draw_line_color: ldx #0 ldy #0 jsr HPOSN ; set page2 sta $C055 ; page2 first ldx COLOR lda color_table,X ldy #0 aux_part1_loop: sta (GBASL),Y iny iny cpy #40 bcc aux_part1_loop ; page2 first ldx COLOR lda color_table+1,X ldy #1 aux_part2_loop: sta (GBASL),Y iny iny cpy #40 bcc aux_part2_loop ; set page1 sta $C054 ; page1 next ldx COLOR lda color_table+2,X ldy #0 main_part1_loop: sta (GBASL),Y iny iny cpy #40 bcc main_part1_loop ; page1 next ldx COLOR lda color_table+3,X ldy #1 main_part2_loop: sta (GBASL),Y iny iny cpy #40 bcc main_part2_loop rts color_table: .byte $FF,$FF,$FF,$FF ; white .byte $3B,$6E,$77,$5D ; 0xB = light blue .byte $33,$4C,$66,$19 ; 0x3 = medium blue