Quote Originally Posted by NavMicroSystems

What kind of help are you expecting if you don't post your code and schematic?
What I'm hoping is that someone will have had similar experience with their large programs and suggest possible fixes.

I doubt you would want to review my code. It nearly fills an 8KByte 16F877, which is why I'm porting it to PicBasic Pro, which supports the larger 18F devices.

The schematic of the serial port interface is directly from the Mechanique app notes.