ESC filters and Re: '90 Calpaks and PROMs

[Marc Randolph]

On Mon, May 01, 2000 at 02:15:43PM -0400, TRAX wrote:
> A quick question from a newbie here ...
> 
> Those of you who are burning chips from years where the PROM is soldered to
> the calpak ... is it possible to make some sort of adapter or do you have to
> unsolder the PROM, erase the chip, reburn it, and then resolder it to the
> calpak?

Yes, although that's more trouble than it's worth, IMO.
The PROM signals pin straight through the MEMCAL case, so all
you have to do is make an adapter to go from the MEMCAL spacing
to a PROM burner spacing (ie, plug your MEMCAL into your adapter,
then plug the adapter into the PROM burner).


Scot Sealander and a few others were talking about ESC numbers a
while back.  I didn't have any MEMCAL's handy, but now I do, and
as I suspected, what I have doesn't appear to match up at all with
the filter numbers he posted.  Here's what I have:

BCC  DateCodeOnUVPROM   ESC filterNumb  Other code in  Other number at
                                        middle of ESC  bottom of ESC
--------------------------------------------------------------------
BFXB  17 week of 1990      10060075       1AD-2           06
BPPA  46 week of 1994      1064305        7KR-3           06
BMCB  20 week of 1997      1407139        7KR-4           40


BFXB is for a 1991 YZ body, BPPA is for a 92, and BMCB is for a 93-95.
Interestingly, the BMCB has the number "8", just floating
above the R in 7KR-4 while the BFXB has a "4" floating in the 
upper right corner. The BPPA has a 6 floating above the R.

The vast majority of traces on the three ESC's look identical. 
Very few differences.  The really noticeable difference is the
size of the components - some caps got bigger, others got smaller.

Any ideas on identifying what any of the numbers mean or which ones
may be plug in replacements for others?  Just how many different
ESC's can GM really have?

Have fun,

   Marc

-- 
  Marc Randolph     -    mrand at pobox.com    -     PGP keyID: 0x4C95994D
     If you have any info on the mid-60's car called the Bill Thomas
       Cheetah, or know anyone that might, please contact me.
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