It occurs to me that the harvard architecture is not so much a limitation as the lack of RAM space. Other embedded systems deal with similar issues (code in ROM, for instance) by simply copying all the data to RAM during startup. That would leave only pointers to code as an issue, and they're less common... BillW -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist