Re: GALs and old PCBs

matt wrote:

On Tue, 21 Feb 2006 16:11:14 +0100, "Deefoo" <nonono@xxxxxxxxxxxx>
wrote:



-25 is for speed, not for age ;o)


I know that. :-)


There is no reason to assume that your GAL would be of the right speed for a
25 year old PCB. Your GAL may be too fast or too slow. Don't you have the
original GAL?


No - the original chip was an 82S153 PLD, it's just that someone
converted the contents of that to JEDEC format to work with a modern
GAL (82S153's are hard to find and expensive). It worked for him, just
can't figure out why it won't work for me.

So perhaps I should buy and try a faster GAL? -15 perhaps? -10? -7?


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.

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.

Cheers
.

Relevant Pages

  • Re: Open with
    ... >From the open window, Click the browse button. ... .pdf program eg. ... Matt ... > Hi guys and gals ...
    (microsoft.public.windowsxp.general)
  • Life is good
    ... I just wanted to say, to all you guys and gals on URB, have a fantastic ... even you Matt you lurking twat)!!! ...
    (uk.rec.bodybuilding)
  • Re: GALs and old PCBs
    ... matt wrote: ... The board is okay as it works with the original 82S153 (which I can't ... I'm guessing that that guy who created the JEDEC file (a few years ago ... GALs and ask him to test it, or even reprogram it for you? ...
    (sci.electronics.basics)
  • Re: Is there any way to play 6 against 6?
    ... partners and use a modified Howell movement for 3 tables. ... It has been suggested that it might be fun to mix it up a bit and play ... My first plan was to make 3 pairs of guys and 3 pairs of gals, ... same direction in a round, then we get 2 pairs on each team sitting NS ...
    (rec.games.bridge)
  • Re: Is there any way to play 6 against 6?
    ... partners and use a modified Howell movement for 3 tables. ... It has been suggested that it might be fun to mix it up a bit and play ... My first plan was to make 3 pairs of guys and 3 pairs of gals, ... same direction in a round, then we get 2 pairs on each team sitting NS ...
    (rec.games.bridge)