start:
INBOX
JUMP     out

up:
BUMPUP   14
COPYFROM 12
 
out:
COPYTO  [14]
OUTBOX

loop:
COPYFROM 14
COPYTO   13
INBOX
COPYTO   12
 
compare:
SUB      [13]
JUMPZ    loop
BUMPDN   13
JUMPN    up
COPYFROM 12
JUMP     compare