.global ___udivhi3
___udivhi3:
stz <r0
ldy #1
ldx <r4
lda <r5
div1:
asl a
bcs div2
iny
cpy #17
bne div1
div2: ror a
div4: pha
txa
sec
sbc 1,s
bcc div3
tax
div3: rol <r0
pla
lsr a
dey
bne div4
rtl