Human-powered dot-matrix printer. Direct power. No batteries are involved. Directly powering a dot-matrix printer is challenging, especially when printing longer documents. The power demand is variable and can increase suddenly for a short time. You must pedal very fast to anticipate these peaks. If you fail, the voltage drops, the communication between the printer and the laptops breaks down, and the machine prints the document all over again. Capacitors could solve this. A laser printer has a very high power use during startup and is incompatible with a bike generator (or a small-scale solar installation).
DIY manual for the bike generator: https://www.lowtechmagazine.com/2022/03/how-to-build-bike-generator.html.
History of office equipment: https://www.lowtechmagazine.com/2016/11/why-the-office-needs-a-typewriter-revolution.html
