Re: Programming 74ALS188 PROM

On Wed, 28 Mar 2007 07:50:41 +1200, Jim Granville
<no.spam@xxxxxxxxxxxxxxxxxxxxxx> wrote:

Joachim Wunder wrote:
On Tue, 27 Mar 2007 11:30:59 -0400, James Beck
<jim@xxxxxxxxxxxxxxxxxxxxxxx> wrote:


In article <0j7i03l1vkigstphhbbmkdff58b5q4uhfd@xxxxxxx>,
Joachim_Wunder@xxxxxxxxxxxxxx says...

Hi there,

I have a working 74ALS188 PROM. This is a (32 x 8) 256-Bit TTL PROM. I
need to duplicate this working 74ALS188 PROM but I still have no clue
where to start with in terms of required programming device, nor do I
know the programming algorithm for this PROM. Can anyone please shed
some light on how this PROM can be duplicated and where to still find
a programmer which is capable to handle this really ancient component?

Thanks in advance.
Joachim


Are you sure you don't mean a 74S188?
I never heard of an ALS version of PROMs.
I know our (as in I own two) DataMan 48XP can program most of the
bipolar proms including the 'S' series.

www.dataman.com

Jim


Yes, the PCB manufacturer of my garage door opener told me that it´s a
74ALS188 PROM. The IC itself has no parameter/order number/type
printed on it (to prevent any copyies of the whole garage door opener
PCB, I assume). The PCB is from the year 1990 and even includes an
Intel 8748 µC on it.

Moreover, do you happen to know any semiconductor vendor who still
produces such PROMs? I am located in Germany, and I still wasn´t able
to find anyone who has any 74ALS188 PROMs in stock. So, an equivalent
type of this PROM would be the second best chance to find such an
ancient PROM, I believe.

Regarding the programmer, a used and more affordable solution than a
brand new DataMan 48XP would be much more reasonable for me. Anyway,
thanks for your kind offer.

you have two problems, one is sourcing a device, and the other is
getting the code out of the one you have already
[if it's good, why do you need another one ? ]

The easiest is to try and borrow a programmer that will read a S188,
and also program a fuse-compatible version, if you can find one.

Look at the 82S123 - that is still on shelves, and is 32x8 BPROM.
See if that is pin-compatible ?

-jg

I soon will have the chance to get access to an old Pro-Log M980 Prom
Programmer. As far as I understood from its manual, this programmer is
capable of even copying a source PROM to an empty target PROM. So,
this should do the trick, I believe.

And, yes, as far as I could derive from the 82S123 data***, this
PROM should really be compatible to my existing 74ALS188 PROM. Thanks
God!
.

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