Thanks for your replies!

Developing off target for protocol implementation is exactly what I am starting to do as well, but have not found much on making it happen. Did you learn to do this through experimentation or did you have some resources to help you out?

Also, are you using the exact same files for compiling both on and off target, or do you create two seprate versions? Do your tests become something that you run as a validation check whenever you make code changes, or is it used as a type of advanced debugger, (e.g. whenever you need to investigate something specific)?

Someone should write a book on these issues, and specifically how they relate to the 8051 development (or perhaps other small mcu's). Alternately, I wish that there was some kind of open-source project that did these things so the rest of us could learn.

You don't know of anything like that, do you?

--David