Apple II Rev. C SCSI Card PALs

[dankcomputing]

I have here an Apple IIGS that I've been trying to fix up for a friend. The SCSI card is busted, it basically acts like it isn't even plugged in. I was able to borrow another (Rev. C) SCSI card, and that works with the existing hard drive setup.

By exchanging parts between the good card and the bad card, I've been able to verify that the problem with the bad card is that it's PALs are defective. The card works with PALs from a known-good card. The problem is, the working PALs are read-protected! The bad PALs aren't, but when I dumped them and burned new PALs based off those dumps, they didn't work either. So I really need dumps of a known, working 342-0415-A and 342-0416-A 16L8 PAL to fix this card. Can anyone help? Multiple clones of this card have been made, good dumps of these devices have to be floating around somewhere.

 

[george]

Well, on these original Apple cards only 3 chips are socketed -- the EPROM and the 2 PALs. Do you know what the chances are both PALs to become defective and nothing else? And add to this the fact that only socketed ICs "burned". For repairing one card you could have ased for programmed PLDs, instead of:

I really need dumps of a known, working 342-0415-A and 342-0416-A 16L8 PAL to fix this card

 

[dankcomputing]

Well, I know the EPROM is good. If someone was selling pre-burned replacement PALs, I would have bought them just to know they worked for peace of mind.

Anyway, here's the dump I was able to do of the bad PALs that weren't protected. With Apple's PALs and other read-protectable PLDs, it seems that some are read-protected and some aren't....

 

[dankcomputing]

I did eventually get this sorted, but as far as I know the dumps aren't public yet. I was able to reach out to one of the people currently selling clones of the card for a replacement, so if you're in the same bind as me that could be an option.