Does anybody know how I can power up a Motronic 1.8 on my desk
separated from the car without just creating smoke?

By eprom emulator and home-made diagnose software I would like to
figure out how the hardware works, and thereby be able to understand
the original software and what the almost 80 different maps represent.

Also does anybody know what serial protocol the volvo scan tool uses to
read live data from this old non-OBDII ecu?

By connecting to diagnose cable number 2 at the blink unit this is
possible with the volvo tool.

Does anybody know anything interresting about the Motronic 1.8?
Like schematics, RAM addresses for inputs and outputs, meaning of
bit-flags in the code, map axis descriptions, calculation formulas for
map values to real values, tuned binaries, ....