What are Vacuum Tubes?
Vacuum tubes are devices that control the flow of electric current in a high vacuum between electrodes to which an electric potential difference has been applied. They were fundamental components in the early development of electronics and were widely used before semiconductor devices like transistors.
Vacuum Tubes in Computers
The vacuum tube is a hardware technology that is used as a basic component of memory and circuitry for the CPU. The input to computers is punched cards or paper tapes and the output is printouts. The instructions are written in machine language as binary values 0 and 1.