bfc

    ld a, (hl)
    ld b, a
    ld a, (de)
    ld c, a
    mlt bc
    push bc
    inc hl
    inc de
    ld a, (hl)
    ld b, a
    ld a, (de)
    ld c, a
    mlt bc
    push bc
    inc hl
    inc de
    ld a, (hl)
    ld b, a
    ld a, (de)
    ld c, a
    mlt bc
    pop hl
    add hl, bc
    pop de
    add hl, de
    push hl
    ld a, (ix+2)
    bit 7, a
    jr z, +_
    ld a, 1
_:
    pop hl