Re: UDC short mystery - 2 different cards that both hate my Apple 5 1/4" - Different revs?

[David Wilson <mcs6502@gmail.com>]

On Jun 12, 5:24 pm, "atfphotogra...@gmail.com"
<atfphotogra...@gmail.com> wrote:
> http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId...
>
> Is that a good source for EPROMs?

I will let someone closer provide a recommendation (I am in Australia
so my preferred retailers are unlikely to be the same as yours).

> Thanks again for all the info.

Glad to be of assistance.

P.S. My green card has the same 27-692-1-0 part number on the LSI chip
as your gold card and the dates on the chips are of a similar vintage
(your green card is circa 1987 while your gold card is 1990 based on
the YYWW dates on the chips). It looks like the newer LSI part
eliminated the need for the 16MHz crystal.

Watch out if you ever come across a Texas Instruments TMS2716 - it is
different to all other 2716 parts (needing multiple voltage rails) -
the TI equivalent is a TMS2516. Just to make things complicated, the
TMS2532 is not a 2732 equivalent part!