Hi Steven, > I am trying to interface your PIC programming hardware > to a Sun SS20. As I have no experience with doing this I'll copy my comments to the PICLIST just in case anybody can help you with some more concrete advice. > The Sun has a centronix type parallel port. > I'm running into a problem where I think my parallel port > needs a data strobe in order to read/verify data from the > PIC that is being programmed. It just so happens that I am using a Sun to write this message but it's one of the low end machines which doesn't have a parallel port (apart from SCSI - which might be another approach to consider I guess) so I can't try anything here and what follows is pure speculation. If you look at the programming spec of the 16C84 you'll see that data is clocked in or out of the PIC on the negative edge of the RB6 signal. It might be an idea to feed this signal (possibly inverted) back into the strobe pin. If you get no joy, then, perverse as it sounds, and again exploiting the fact that you know that data will be valid on the negative edge of RB6, you could generate the required strobe signal on one of the data out pins and simply feed this signal back into the strobe pin. Let me know how you get on. David -- david.tait@man.ac.uk