Are computers of alien technology

No, but they were greatly stimulated by IFO"s Identifiable flying objects of the Armed Forces ( ICBM guidance mechanisms, for example) and space craft, satellites- and so on. Microlectronics really took off- with the coming of Space technology- Man made, not alien. Transistors, subminiature tubes ( preferred by the Russians for some reason) and integrated circuits all play a vital role.