From: "Brooke Clarke" > Can I read and/or program the 1702 with the PicStart+? NO! The 1702 is an extremely old EPROM of early 1970s vintage. It requires 3 power supplies for programming and has about the most arcane programming algorithm that you can imagine. Involves raising and lowering various voltages in an interesting manner, meeting setup times etc. You definitely require a specialist programmer to handle it. AFAIR the spec also called for data to be applied inverted and then inverted for a certain peiod of time and then re-inverted to the correct value a certain time before programming. Also, AFAIR the friend mentioned below friend found that you could ignore this requirement :-). I have copied this message to a friend who built a 1702 programmer in about 1974 when the 1702 was about all that was available. I suspect he can't add a lot to the above but he may care to comment to you directly. You could search for a programmer able to handle 1702's (Holtek amongst others advertise them). If I was in your position, depending on whether the cosmetic aspects were important, I would be tempted to read the 1702's if necessary (much easier than programming them) and build an adaptor for a more modern EPROM. Failing that, reading the EPROMs should be easier and you could find a specialist service to rewrite them once you had made the alterations. . Russell McMahon ____________________________________________ > I have an AN/PSN-6 Loran-C receiver that has a couple of 1702 EEPROMs in it the > tell the receiver that it should look for Loran-C chains in the area of Fort > Bragg, NC. I would like to reverse engineer the contents of these 1702 chips so > that I can reprogram them for central CA. > http://www.pacificsites.com/~brooke/PSN6.shtml > > > If not what's needed? > > Thanks, > > Brooke Clarke, N6GCE > http://www.prc68.com -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu