On the fly mods & checksums.

[Ron Gregory]

>Just thinking about the emulator thing and I was wondering what happens
with
>regards to the checksum as you are happily changing values on the fly and
>the checksum value isn't being updated?, will the ECU code a faulty ROM?.
>Or is the checksum only checked once on each power up or something?.


The checksome is only checked at reset as far as I can
tell, but there's a byte that you can set to disable the check.

But I think we're going to have to reset the ECM, because
I think there are places where the code loads a value out
of the PROM and sticks it in RAM to work with it.

What does the ECM do if the 6811 is reset while it is
running... will it be able to detect that the engine is
running and resume fueling, etc.?
I know there's a lot of RAM cleared at reset/startup.

There are certain things that are done at start up,
that may be reset.... e.g. start-up coolant temp
and baro pressure... what's going to happen here?

Just thinking and typing at the same time...
~~~~~~
Ron Gregory                 Syclone VIN #1452
rgregory at iname.com          Garland, TX