Re: GALs and old PCBs

On Tue, 21 Feb 2006 17:28:32 -0500, Sambo <sambo@xxxxxxxx> wrote:


Ah, pals and gals maybe I'll still get a chance to play with those.
I would say you are most likely already way too fast, 250-300ns RAMs in those days, 82S153 probably had propagation delay of at least 40ns
come to think of it it is not even PLD it is a PROM hence even larger propagation delay can be expected. A quick glance on goole, I don't
see anythink with specs ( so many useless hits these days $#*%^& ) It is not in the "CMOS cook Book" must be in "TTL Cook Book" anybody have it handy?
Of the top of my head I don't even think it has an enable signal which you could .....
The old slow part may be bridging the time the inputs stop being valid and the outputs are read (since I don't believe the part has output enable),
the only way would be to buffer the outputs or use a device that could delay the outputs internaly.

Hmmm, thanks. Wish I could find a slower GAL! Do they still exist?

Why it worked for the other person (with same circuit, same speed and type GAL ) can't say. Maybe you can get a bit slower GAL and get lucky.

That's the problem - any ideas where from? :)

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