But before even those transistor-based computers is a retrocomputing era rarely touched on: the era of programmable vacuum tube machines. [Mike] has gone back to the 1950s with this computer which ...

The transistor was a solid (thus the term "solid-state technology") but had the electrical properties of a vacuum tube. Yet it had none of the drawbacks: it was cheap, sturdy, used little power ...

Vacuum tubes were widely used as diodes and triodes in the electronics ... there's a layer of p-type semiconductor material sandwiched between two layers of n-type material. In a PNP transistor, the ...

circuits [David] has already built vacuum tube versions of. The only part left was the discharge transistor; a pentode was enlisted to stand in for that vital function, making the circuit complete.

If transistors could replace vacuum tubes in the phone system, then they certainly could replace them in computers too. The army, with its need for ever-faster and more efficient calculations ...