Problematic PLDs – The Answer is Near…

The problem that I have been having with PLDs in the recent past may be close to being resolved.  The last few times that I’ve ordered GAL22V10s from any source my programmer, a TL866 (aka:  MiniPro), has been unable to program them. Considering that my G80-S Computer requires this PLD for it’s decoding logic, and that many users do not have a means to program these chips, this creates quite a problem.  So I have set out on a quest to see if the problem with the over 120 GAL22V10s that I have have in my possession is truly a problem with the ICs, or if it is an issue with the programmer.  I suspect the second is the cause.

So, I have ordered a batch of boards for the ‘ELM Simple GAL Programmer‘ and have built one to test.  Above is the board.  The person who designed the board used a Male to Male 24-Pin Serial Cable for some reason, rather than a proper Parallel Cable.  I do not know why.  But Since I do not own a 24-Pin Male to Male cable, I’m waiting on one to arrive.  The rest of the board is done.  I’ve already applied voltage and test the VCC and the 15v lines, and adjusted them to their proper voltages.

Assuming this works for programming the 22v10s that I’ve had so many problems with, I will likely redesign this board so that it is a little more proper, and then offer it in the RetroDepot store.  However, I will likely sell off the extra boards that I ordered once I confirm they do in fact work.  Until then, no sense in selling PCBs that I’m unsure of.

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