Intro to microcontrollers (long)

[Roger Heflin]

On Wed, 26 May 1999, TK wrote:

> What I tell everyone is that the program is not really of importance. The
> tables are the important part. Even the most rabid of us GM ECM hackers
> don't change the program code, only the data tables. It's interesting to see
> how GM goes about using the data in the program, but it's easy to get side
> tracked on the program.
> 
> Data tables. Layout, inter-relationship, etc.
> 
> Terry Kelley


I must be seriously rabid then.  I have so far changed the code in 3
major ways.   I adjusted some of the way the int's and blm's worked on
my ECM.   On mine when the BLM was adjusted the int was not adjusted,
I changed things so that when the BLM was adjusted the int was changed
by an appropiate amount to maintain constant mixture.  This has
appeared to make the car run better with the VE being off since the
fuel mixture gets to the right point much faster with less
oscillation. 

I also rigged the fuel curves to be per gear, I don't know if that has
actually helped any performance, and I added some code to lock the TCC
at the top of second gear (and unlock it at the bottom of 3rd).

So far adding code was not that hard.  I have only had 1 revision of
code that actually caused the computer to watchdog reset, and since
then I have been much more careful checking things.

			Roger