10 rem setup :
20 read p
30 peek p
40 save a
50 read q
60 peek q
70 save b
100 rem the real program starts here:
101 peek p
102 save t
103 peek q
104 poke p
105 load t
106 poke q
200 rem and again:
201 peek p
202 save t
203 peek q
204 poke p
205 load t
206 poke q
1000 rem now check that nothing changed:
1001 peek p
1002 eq a
1003 jmp 1005
1004 exit 0
1005 peek q
1006 eq b
1007 jmp 1009
1008 exit 1
1009 exit 0