GAL/PAL programming algorithm?

[eccerr0r]

I find it a bit odd... I can't seem to find the programming algorithm, say, for the old AMD PALCE20V8 if I wanted to get an Arduino or PIC to program these old units.

At least the algorithm doesn't seem clear in the datasheet, it just says "Any programmer can do it" or something to that extent -- well my programmer does not program the AMD PALCE20V8 properly!

Anyone seen a datasheet that actually describes the algorithm much like how most EEPROM datasheets include such data?

[stj]

Re: GAL/PAL programming algorithm?

it's a trade secret they sell to big-name programmer makers.

your only chance afaik is to look at some old programmer project some guy wrote on the amiga - i think he shared the code.
http://aminet.net/package/driver/other/GALer21

[eccerr0r]

Re: GAL/PAL programming algorithm?

Wow, is it that much of a secret? That's insane...
Hope the GAL algorithm works for the PALCE... or perhaps they do have PALCE. Never know they may have minute differences between them?

Ugh, it looks like one needs to reverse engineer their hardware along with the software to really understand what's going on with GALer... might be too much effort, may well reverse engineer the PALCE algorithm I already have (it's virtually a .exe file unfortunately.) This effort would at least figure out how to write new algorithms with my device programmer too...

[stj]

Re: GAL/PAL programming algorithm?

no idea.
i suspect it may have something to do with not letting people know enough to possibly bypass the protection bit.
if true - they failed!!
http://dreamjam.co.uk/emuviews/readpal.php

[eccerr0r]

Re: GAL/PAL programming algorithm?

Possible, though yeah as they say the V devices can get hard if it uses internal feedback. I think the R devices don't have internal feedback? If not then these can be duplicated this way too...

[eccerr0r]

Re: GAL/PAL programming algorithm?

BTW what would be funny is using a logic analyzer to reverse engineer programming...

[stj]

Re: GAL/PAL programming algorithm?

only problem i have is the possibility of it using over 5v.
you would want to scope each pin first to check for anything like that.

[eccerr0r]

Re: GAL/PAL programming algorithm?

It wouldn't help in my case as I know it's wrong I would need someone else to snoop
But yes likely it may require a high voltage pulse to program bits like old UVEPROMs... I just don't know if they made them so they could be written with single supply like modern AVRs and PICs...