SoylentNews

owl [soylentnews.org] writes:

I amuse myself by constructing a computer almost entirely out of relays. Relays were used to construct computers well before vacuum tubes, transistors or integrated circuits were feasible for the task. The main inspiration is the machines by Konrad Zuse of the late 30s and early 40s.

Why relays? In addition to constituting an important historical link between the mechanical and electronic computers, relays are especially fun to work with since they

• are big and slow, with huge propagation delays and a tendency to oscillate if you hook them up wrong.
• are noisy, especially when lots of relays switch at the same time.
• consume lots of power to do even the simplest of calculations.
• subscribe to Lenz' law, i.e. generate lots of EMF and flyback current that make for all sorts of interesting interference in places you couldn't even guess.

So all in all, relays require you to think in very new ways compared to normal solid-state devices.

Original Submission