RM> your program terminated. There's a loose convention (not a rule)

It is a rule.  0 means success according to the Australian, American and
International standards for the C programming language.

RM> that says you return 0 for normal termination, and non-zero values
RM> for abnormal termination. 

The only things defined are 0, EXIT_SUCCESS and EXIT_FAILURE.

You could give the official version and then say "in the dos world you
might want to do xyz instead".  BFN.  Paul.

P.S. I tried out your code, but couldn't make it print the reciprocol of
360 (or whatever).  If you have something that does that, and are happy to
stick a PD notice on it, I would like to include it in OZPD as a routine to
do maths manually. 
@EOT:

---