John has a great round up of some retro computer design – “A working eight bit computer made out of Relays! For some time amateur computer designers have been getting ‘back to basics’ and building their own computer designs with individual TTL logic gates wire wrapped together. One determined experimenter even built his own out of individual transistors. But Harry Porter has gone even further back on the technology scale, building a functioning eight bit computer out of 415 individual relays. His one concession to modern times is the computer’s memory, everything else goes clickity-clack blink-blink.”