Prom ID's

[Ludis Langens]

"Bruce Plecan" <nacelp at bright.net> wrote:
> The 1227148 turbos use a 41 entry.

Location 8 in a '148 PROM is in the ignition advance table.

> If you can read any gm bins, and look at the 0008 please do so.
> I'd really like to see if there is more in common amongt the bins
> that we may know.  If ya want to e-mail me, or post it to the list
> PLEASE do.  
> Id really like to put together a list of ecm's and prom ID's, 

Bruce and Wayne: Now you've done it!  We'll be talking about the $31 and
$42 PROMs and AU$5D MEMCALs.  Outsiders will have no idea what we're
talking about.

Here's a list of "experimental" locations and normal values:

1226864
$E004 aka $004 == 28 or $1C

1226867
$D002 aka $002 == 32 or $20

1226869
$356D aka $56D == 36 or $24

1227170
$3587 aka $587 == 36 or $24

1227148
$37A2 aka $7A2 == 49 or $31

1227747
$D004 aka $004 == 66 or $42

1227783
$3004 aka $004 == 68 or $44

1227748 w/ ACMH
$C008 aka $0008 == 72 or $48

1228321 w/ ARRP
$C008 aka $0008 == 80 or $50

1227808 w/ ASBX
$C008 aka $0008 == 93 or $5D

1228746
$D004 aka $004 == 97 or $61

16136965
$D004 aka $004 == 98 or $62

As you can see, the location of this byte moves around, and sometimes
isn't even near the beginning.  It is also does not fully identify a
specific ECM program.  The 1226869 and 1227170 are for different years
of the same application, but their PROMs are not compatible.  Yet, they
have the same code number.


[Gee - I had thought this byte was a carefully chosen bit pattern used
to quickly detect an empty or defective PROM socket.  The first two ECMs
I dumped ('6869 and '7170) have the same number and it forms an
interesting binary pattern: %00100100.]

               unsigned long BinToBCD(unsigned long i) {unsigned long t;
Ludis Langens     return i ? (t = BinToBCD(i >> 1), (t << 1) + (i & 1) + 
ludis at cruzers.com            (t + 858993459 >> 2 & 572662306) * 3) : 0;}