First Generation Computers. A Vacuum Tube First generation computers were between the time period of 1946-1959.The first generation computers used vacuum tube technology for their various processes.The first generation computers were very large and require large storage areas for them .The invention of the vacuum tube technology opened the gates for the development of electronic computers.The earlier electronic computers before the vacuum tubes used relays instead.Vacuum tubes were used as electronic switches and also for circuitry and magnetic drums for the memories..Vacuum tubes could work faster and were noiseless as compared to relays. In 1943, a first generation computer ,Electronic Numerical Integrator And Calculator(ENIAC),was developed in the university of Pennsylvania. ENIAC contained nearly 18,000 tubes and consumed more the 150Kw of power.It was very big and weigh more the 30 tons. It could perform thousands of multiplications and hundred of additions per second. The c...