https://en.wikipedia.org/wiki/Interlocking#Relay_interlocking


http://relaysbc.sourceforge.net/circuits.html
  Relay latches and flip-flops
  Low relay count master-slave flip-flop
  http://relaysbc.sourceforge.net/rmslave.gif


https://en.wikipedia.org/wiki/Z3_(computer)
  https://en.wikipedia.org/wiki/Konrad_Zuse

https://en.wikipedia.org/wiki/Z1_(computer)
https://www.bbc.com/news/business-53413931
  Bo Ewald, chief executive,ColdQuanta,Colorado qubits 
  Prof Andrew Daley at the University of Strathclyde  Jonathan Pritchard
  weird phenomenon called entanglement
  French company Pasqal  Christophe Jurczak, chairman, energy giant EDF

https://en.wikipedia.org/wiki/Colossus_computer
https://en.wikipedia.org/wiki/Atanasoff%E2%80%93Berry_computer
https://en.wikipedia.org/wiki/ENIAC
https://en.wikipedia.org/wiki/Manchester_Baby
https://en.wikipedia.org/wiki/Manchester_Mark_1