I suggested that after the Final Countdown first computers are made with Rope Memory and Mechanical Relays. But Ken Schirriff said NO -- you need semifast semiconductors to read the memory.

I would love to see a relay switch at 1Mhz.

You will amazed. One reason is that relays are suitable for multilevel signalling. That is why the relays-only Fuji computer was on par with contemporary Amerikahito crap.