PHP
    SEP #$30
    PHX
    LDX #$03
.loop   LDA $17C0,x
    BNE .next

    INC $17C0,x
    LDA #$1B
    STA $17CC,x

    LDA $98
    AND #$F0
    STA $17C4,x
    LDA $9A
    AND #$F0
    STA $17C8,x
    BRA +

.next   DEX
    BPL .loop

+   TXA
    PLX
    PLP
    RTL