; Integer divides A:C by DE
; Result in A:C, remainder in HL
; Clobbers F, B
    ld hl,$0000
    ld b,16
-:  sll c
    rla
    adc hl,hl
    sbc hl,de
    jr nc,+
    add hl,de
    dec c
+:  djnz -