Originally Posted by
kur4o
The shared ram in 94 pcm is between 1400-16FF and I guess 400-8FF is also in relation with it. There are even some subroutines called at that range.
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I am gathering some pics from different pcms to see what chips GM used as TIO.
While comparing the code between 94-95 and later 96-97 pcm the access of the shared ram seems a little different.
While you are still there can you trace the pins of the knock module. I managed to find that 2 pins are connected to it for 2 different knock sensors, 1 gets 5v and 2 pins goes to tio or some other chip, I can`t interpret my old drawings better. I disassembled the knock module but can`t tell much of it. It looks like the older memcalls. Some ultra small chip and a dozen of condensers.