oops, ignore that last one (corrupt e-mail program on PC, switching to a Mac now...)

I recently got my AP-64E EPROM Programmer working after having spent many hours/days/weeks drawing the complete circuit on Protel so I could try and figure out what was broken.

In the end I discovered that I had in fact set up the dip switches wrong. After re-checking my original manual and Waynes .pdf version I noticed a possible cause of confusion in the dip switch table. it shows all combinations of dip switches for 2716, 2732 and 2764 EPROMs using an "o" or an "x" to indicate it's state. What isn't mentioned is whether the "o" means open or closed, or whether the "x" means open or closed !. This is a critical omission.

This is where I went wrong, I had mistakenly thought that the "o" was open and "x" was closed, where in fact it should be the other way. ie. "o" is closed (on) and "x" is open (off). 

I had even printed my own fully formatted A5 size manual adding a note incorrectly, which I will now change. There was already a note of caution in the manual stating that your EPROM could be damaged if the switches are wrong and now that I have drawn the circuit I can understand why. It is quite possible that if the switches are wrong and an attempt to burn an EPROM that the programming voltage (about 25V) could be fed back to the wrong pins on the EPROM or even the PIA.

I guess in the worst case you could even feed that 25 Volts back to your reliable old Apple II motherboard, this is why I am now cautioning others that have this programmer, to ensure that you make a note in the book to indicate which way is correct. If you don't have the book, Wayne's website does, and I will also put my version up soon too, with some modifications that can be done to read 27128 EPROMs, which I only just tried successfully last night. simple mod in most cases.

I will also put up a circuit diagram of the board, however in the meantime anyone wanting a copy of the protel file can just e-mail me at:
figjams AT primus DOT com DOT au
(you know the deal)

Incidently, anyone know how to convert a Protel drawing into some image format, like GIF ?, otherwise I have to print it and re-scan it, losing some quality and squareness.

Mark.