The MPLAB package has a template routine (in c:\program files\mplab ide\templates) by the name of F452TEMP.ASM. When I assemble this all by itself, with no changes whatsoever, and then use the Wisp628 programmer to program an 18F426 chip running at 10 MHZ (ceramic resonator) then I consistently get the following error from xwisp: "IO Error: Verification failure. Different data at 300007. File=FF Target=00" Now, I can load Wouter's little LED program, compiled with JAL, into the chip and it runs fine. Which tells me that the Wisp628 is working and that the PIC is working. Therefore, there must be something about the Wisp628 and/or xwisp, and that template file. But darned if I can figure what it might be. Anyone have any ideas? (Someone is bound to wonder why I even want to assemble that template program and load it? Because my original program consists of more than just that, but I have narrowed it down to just the template part causing the problem. I think, :-) John -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body