I'm trying to port some code over to the PIC from a Motorola 68HC series chip (ugh). Anyone have an instruction set that I can reference for this? You haven't given enough numbers to specify an instuction set yet. There are (roughly) 68HC00, 68HC05, 68HC08, MC6809, 68HC11 and 68HC12 in the "small microcontroller" range, all with significant architectural differences (I think some or all might be considered by some to be "logical extensions" of one another.) Then you get to the 68HC000 and later higher-powered microprocessors... In any case, all the databooks are online at http://www.mot-sps.com/ BillW -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.