I think I'm beginning to get it. Attached find my second try at a prime
number generator.

This one is distinguished from my first by two important differences:

1: It is written (I think) in a completly functional style 
2: It actually *works*. It's pretty fast too. Running as an optimized
binary on my system (Athlon @ 950mhz under FreeBSD 5.1) it can calculate
the first 15104 primes (Highest is 165161) with one minute of CPU time.

Thanks again for all your help!