I have a unique application that is about to overflow 64k. I can not use bank switching because of the overhead. PLEASE do not reply anything about how small the overhead is - I do not care, there IS overhead. Now this application process ONLY ONE OF two formats "classic" and "current". My idea is to locate all common code in the lower 32 k and, immediately after reset detect which format it is and set the COBANK bits so that either page 1 or page 2 would be code addresses 8000 to ffff to process the actual format. I know of no simple way to do this, suggestions appreciated. Erik Cross posted on the SILabs forum.