Memcal BCC Numbers

[Ross Myers]

Hi all,

I've been trying to figure how the number codes on the BCC may relate back
to the actual code in the EPROM.
Mythical example BCC - ABCD1234 , how is that 1234 generated?, is it just a
random number the factory picks, do you add $xx - $yy and this gives you the
number?.

What I can say is the 'double byte PROM codes' get close. Here's some
examples-

BLJX6413 - Dbl PROM I.D val = $1912, convert to dec = 6418
BWCS9976 - Dbl PROM I.D val = $270E, convert to dec = 9998
BMZA1754 - Dbl PROM I.D val = $06DE, convert to dec = 1758

Here's the hex line from the BMZA1754 I get this from -

06DE FFFF FFFF 5C0F 11 {CALS FROM HERE ON}

ARGGG, only a few bytes off in all cases, I can't pick it, anybody else?
Note - these are from Holden Memcals, though I can't see them being much
different.

I've got alot of bins with only a letter code listing, as we all know GM
likes to double up on these thats why the numbers in the BCC are also nice
to know.

Thanks

Ross Myers