Maybe it was just implemented with too much abstraction, which can make things more confusing. Instead of porting it as-is, rebuild it with the actual function

Maybe it was just implemented with too much abstraction, which can make things more confusing. Instead of porting it as-is, rebuild it with the actual functionality required and throw away the overly abstracted parts. Oh, and I echo the other guy: make sure you have a test harness that validates everything, so you know if you've done it correctly.