I hope to find a simple answer, but not sure if there is one to this question. Whats the difference in the various PIC programmers I see on various links? I have noticed alot of 16C84, or F84, programmers and the hardware is straight forward. Parallax's 16Cxx programmer has a firmware chip but no extra hardware on their PCB. I have the parts to build a simple 16C84 programmer that I wanted to use for some 16F84's I just got but not sure if the programmer I was going to build will work for the 16F84, since there seems to be some issue of it can only program the 16C84--I thought the chips were (C84 and F84) about the same. Question #1: Can I use a simple 16C84 programmer ( the one I had intended on building is called the "COM84") to program 16F84's? Question #2: Whats special about these programmers I see for all of the other 16Cxx chips--is it firmware or what? If I use Parallax's SPEP.exe software to program, lets say a 16C56 or 57, and use the simple programmer I wanted to build for the 16C84, would this work or kill the 16C56 or 57? Qestion #3: Whats the alternative if a simple programmer ( such as the one for 16C84's) won't work for other 16Cxx chips short of buying a commercially made programmer such as Parallax's? Are there any homebrew programmers out there for the 16Cxx series PIC chips that can be built from scratch? Any help, suggestions, or direction would be graetly appreciated!! Thanks in advance for any replies... Mike Regards... Mike Hall - "http://members.aol.com/mhall34450/" WB8ICN Dayton, Ohio Regards... Mike Hall - "http://members.aol.com/mhall34450/" WB8ICN Dayton, Ohio