>divide address by two, other mysteries There are two Intel file formats that can be used to store PIC binary code. One is INHX8M and the other is INHX16. Unfortunately the tools default to INHX8M which is a strange format. Use INHX16 instead imho, as it is easier to understand. INHX16 stores NN words of 16 bits each per record, and the addresses are calculated as expected. The checksum is still performed on 8 bits however ! (using the higher and lower bytes of each word separately like: word=HHhh cksum+=((HH+hh)%0x100) ) Peter -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.