Panel de Pon Sound Driver Upload Routine

sub_809104:
    php
    sep #$20
    lda #$01
    sta $199c
    lda #$cc
    bra loc_809118
loc_809110:
    ldx #$00fc
    stx !APUIO0
    rep #$10
loc_809118:
    ldx #$bbaa
    cpx !APUIO0
    bne loc_809110
    bra loc_809148
loc_809122:
    jsr sub_809196
    xba
    lda #$00
    bra loc_809135
loc_80912a:
    xba
    jsr sub_809196
    xba
loc_80912f:
    cmp !APUIO0
    bne loc_80912f
    inc
loc_809135:
    rep #$20
    sta !APUIO0
    sep #$20
    dex
    bne loc_80912a
loc_80913f:
    cmp !APUIO0
    bne loc_80913f
loc_809144:
    adc #$03
    beq loc_809144
loc_809148:
    pha
    jsr sub_809196
    xba
    jsr sub_809196
    xba
    rep #$20
    tax
    sep #$20
    jsr sub_809196
    xba
    jsr sub_809196
    xba
    rep #$20
    sta !APUIO2
    sep #$20
    cpx #$0001
    lda #$00
    rol
    sta !APUIO1
    adc #$7f
    pla
    sta !APUIO0
loc_809174:
    cmp !APUIO0
    bne loc_809174
    bvs loc_809122
    sep #$20
loc_80917d:
    lda !APUIO0
    bne loc_80917d
    lda !APUIO1
    bne loc_80917d
    lda !APUIO2
    bne loc_80917d
    lda !APUIO3
    bne loc_80917d
    sta $199c
    plp
    rts

sub_809196:
    lda [$24],y
    iny
    bne loc_8091a0
    inc $26
    ldy #$8000
loc_8091a0:
    rts