Most post-collapse writing I've seen presumes a very long tail of salvageable computation devices not to mention batteries, LEDs, motors, solar panels, plus too

Most post-collapse writing I've seen presumes a very long tail of salvageable computation devices not to mention batteries, LEDs, motors, solar panels, plus tools like oscilloscopes and soldering stations, etc that would all assist in the re-bootstrapping effort. Assuming a planetwide em event is a pretty major wrench in the works and definitely puts you back a lot further in terms of how to rebuild the technology ecosystem.