CPU's

[Ludis Langens]

Bob Wooten wrote:
> 
> the first is how do i determine the Broadcast code?

Download/build a copy of BitHoist.  It'll try to tell you the BCC.

> i have Win Bin, AFR Modifier, &
> data master all loaded up & none of them are telling (or i am missing it).

The BCC isn't in the chip.  The scan id is.  Knowledge of the scan id
can usually lead to a BCC.

> SW Template:
>         The software template, or ID Byte, is always a two bit code that describes
> the layout of the calibration.

Eight bit, one byte, two character, ...

> These are the exact locations of tables &
> formulas that calculations are performed.  By looking @ the SW template you
> can know the locations of the tables in the calibration

Some ID bytes (aka mask bytes) are reused.  GM ran out sometime in the
1990's.  Also, some ID bytes have multiple versions.  For example, there
are probably enough different 1227148 mask $31 variations that all of
Bruce's little guys can have their own.  It isn't currently clear if the
variations have the same table layout or not.

>         The broadcast code is a four letter group that is unique to the actual
> firmware in that ECM.  This is specific to the application (91 Camaro, 5.7L
> motor, 700R4, 3.42 gears, etc) and the calibration.

The letter portion of some BCC's is reused.  It appears that the letter
portion is enough to identify a specific application.  If there are
updated chips for that application, they got the same letter code with a
different number code.  Newer updates (since about 1988/89) seem to have
a new letter code.  This might be because the update often works on a
different set of vehicles.

> The /1563 number is
> the last four digits of the GM part number for the calibration. (BW
> confusion here, why is it +1 digit?)

The +1 isn't consistent.  Often the numbers are close, but they could be
totally different too.

>         The scan ID or the Prom ID is a four digit number that is programmed into
> the firmware

Yet another last four digits of a GM part number.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/


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