Silicon wafer used in the production of Intel 8080 microprocesor chips, 1970s.
© Science Museum / Science & Society Picture Library
Introduced by Intel in 1974, the 8080 microprocesor was the first microprocesor powerful enough to build a computer around. It was used in the Altair 8800, one of the first personal computers, which was available to buy in kit form for $395. This computer became so popular, that within months, tens of thousands had been sold, creating the first PC back orders in history.