color_irq:
        sta $10
        stx $11
        sty $12

// set the colors
        lda new_color_1
        sta $d021
        lda new_color_2
        sta $d022
        lda new_color_3
        sta $d023
// test d012
        lda $d012
        cmp #$f9
        bcc less_than_249
// set d011 here and now

        lda #$13
        sta $d011
// set music_irq
        lda #<music_irq
        sta $fffe
        lda #>music_irq
        sta $ffff
        lda #20 // some top line
        sta $d012
        bne color_irq_end

less_than_249:
// set the special d011 write irq
        lda #<d011_irq
        sta $fffe
        lda #>d011_irq
        sta $ffff
        lda #249
        sta $d012

color_irq_end:
        lda #1
        sta $d019
        lda $10
        ldx $11
        ldy $12
        rti


d011_irq:
        sta $10
        lda #$13
        sta $d011

// set music_irq
        lda #<music_irq
        sta $fffe
        lda #>music_irq
        sta $ffff
        lda #20 // some top line
        sta $d012

        lda #01
        sta $d019
        lda $10
        rti


music_irq:
        sta $10
        stx $11
        sty $12

        jsr $1003

        // rest of the code that sets up color_change_irq when
        // its time and moves it down and all that....