LD HL,0 ; DEHL := DE * BC ; min 445, max 723
  LD A,D
  ADD A,A
  JP NC,skp0
  LD H,B
  LD L,C
skp0:
repeat 7
  ADD HL,HL
  ADC A,A
  JP NC,skp1
  ADD HL,BC
  ADC A,0
skp1:
end repeat
  LD D,A
  LD A,E
  LD E,H
  LD H,0
repeat 8
  ADD HL,HL
  ADC A,A
  JP NC,skp2
  ADD HL,BC
  ADC A,0
skp2:
end repeat
  ADD A,E
  LD E,A
  LD A,0
  ADC A,D
  LD D,A