Dseg at 8
S: ds 2
Cseg at 0
Jmp start

start: clr a
Mov r0,#8
Mov r1,P1
Mov r2,P2
Cikl:
clr c
Mov b,r1
Mov a,r2
Rr a
Anl a,#0x7f
Xch a,b
Subb a,b
Jc belzero
Abovezero:
clr a
Mov a,r1
Mov b,r2
Subb a,b
Mov b,r1
Add a,b
Mov r1,a
clr a
Mov a,r3
Rl a
Inc a
Mov r3,a
jmp finita
belzero:
Mov a,r1
Rl a
Anl a,#0xfe
Mov r1,a
Mov a,r3
Rl a
Mov r3,a
finita:
Djnz r0,cikl
Mov P3,r3
end