Computer

[Mat]

Who built the first working computer that was used effectively but then destroyed on orders from a major government.

 

[pebe]

Who built the first working computer that was used effectively but then destroyed on orders from a major government.

It was the Collosus, built at Bletchley, England, during WW ll. It was used to decode German military intelligence.

 

[Mosfet]

First electric digital computer [base 2] was John Vincent Attanashoff at Ames Iowa US 1938 - no overwheming interest - left it in the basement and mostly forgot it.
Guy who later built ENIAC visited - saw it working and cribbed the design. Couldn't figure out base 2 so he hacked it to base 10.