raster

//```````````````````````````````````````
//raster routine by erol/tempest
//```````````````````````````````````````
raster:
         lda #$30
rs1:      cmp $d012
         bne rs1
         ldx #$06
rs2:      dex
         bne rs2
         bit $ff
         ldx #$00
         ldy #$00
         bit $ffff
         nop
rs5:      nop
         bit $ff
         bit $ffff
         lda rcol,x
         sta $d020
         sta $d021
         inx
         bit $ffff
         cpy #$02
         beq rs3
         nop
rs4:      pha
         lda $d012
         and #$07
         tay
         bit $ff
         nop
         nop
         nop
         pla
         cpx #$34
         bne rs5
         rts
rs3:      bit $ffff
         lda rcol,x
         sta $d020
         sta $d021
         inx
         bit $ffff
         bit $ff
         jmp rs4
//```````````````````````````````````````
rcol:     .byte $00,$09,$00
         .byte $09,$09,$09,$08,$09,$08
         .byte $08,$08,$0a,$08,$0a,$0a
         .byte $0a,$0f,$0a,$0f,$0f,$0f
         .byte $0f,$0f,$0f,$0f,$0f,$0f
         .byte $0f,$0f,$0f,$0f
         .byte $0f,$0f,$0f,$0a,$0f,$0a
         .byte $0a,$0a,$08,$0a,$08,$08
         .byte $08,$09,$08,$09,$09,$09
         .byte $00,$09,$00
//```````````````````````````````````````