Stable raster - I don't know why :-)

:BasicUpstart2(main)

.var brkFile = createFile("bin/breakpoints.txt")
.macro break() {
  .eval brkFile.writeln("break " + toHexString(*))
}


.macro pozycja (liczba) {

loop:     ldy #liczba
         ldx #$00
loop1:     lda #$00


tu:         cpy $d012
         bne tu

         sta $d020


         nop
        :break()

         iny
         adc #$00
         cmp #$0f
        beq tutaj
        jmp tu
tutaj:


}

main:


        sei

        lda #>irq
        sta $0315
        lda #<irq
        sta $0314
        lda #$01
        sta $d01a
        lda #$7f
        sta $dc0d
        lda #$44
        sta $d012
        lda #$1b
        sta $d011
        cli
        rts

irq:
        :break()
         lda #$00
         sta $d011
         sta $d020
.for (var i=0; i<$80; i++) :pozycja($37+i)
.for (var i=0; i<$80; i++) :pozycja($b4-i)