OK, after all that discussion, solving the problem turned out to be short and sweet, so I am proud to say that I can run Xwisp (version 1.05) under both Linux (Red Hat 8.0) and under Windows 98, and use the wisp628 programmer to program an 18f452 chip. The problem under Linux turned out to be that access to the serial port was denied to an ordinary user. But switching over to be root made it work. The version of Python that I did this with is Python 2.2. So, with that out of the way, I now want to play with Rob Hamerling's version of Xwisp, written in C, and see if it will run under Linux. A full report will be given. :-) Ciao, John -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics