Serial Data Idea's.

[Roger Heflin]

On Mon, 10 May 1999, Ross Myers wrote:

> Hi Guys,
> 
> Just thinking the other day, is it possible to write new serial data modes
> into a PROM. What I mean by this is, for example Mode 1 will spit out data
> parameters on sensors etc, but how about telling the ECU to spit out values
> from the Cal tables as say mode 0E.
> ie - define it as a say 128 byte word, point it to the address of say Spark
> V's CTS and the CALS will spit out? possible or not?.
> The ultimate Scan tool that can plot CAL graphs (or does it already exist?).
> 
> Thanks

Having looked at the ecm code (and the ALDL output code) I cannot see
a reason it would not be possible.   The standard gm code uses
indirection, ie there is a list of addresses of what data to output,
so if you made you own mode and put in your own list of addresses, it
would be dooable.   Look on http://www.hit.net/~rah then click on
promwork then clock on notes and in notes the two SCI links are
flowcharts of the ALDL output routines for a 93 Z28.  From what others
have said these output  routines are all pretty similar on the late
model vehicles.

			Roger