Looking for ECU and / or ISM schematic

[a2wolfsburggli]

I'm currently looking for the ECU schematic for the Digi I and the ISM schematic.

Not looking for the troubleshooting manual, not looking for the wiring diagram.

I'm looking for the actual technical schematic for the ECU or better yet the ISM.

Reason for this is that I have a friend that works for a major boat motor mfg and can potentially reproduce the functionality of the ISM with an Aduino or simple comparator circuit board that we could then get into the hands of everyone here.

He'd like to reference the circuits that were used and see what he can build up for us.

All the links here and on google searches are dead ends at this point. If anyone has any help or an old buddy that may have been around Bosch or VDO back then or potentially worked on the inner circuit boards?
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