First Generation Computers (1945-1955)

First electronic computer used vacuum tubes, and they were huge and complex. The first general purposes electronic computer was the ENIAC (Electronic Numerical Integrator And Computer), It was digital, although it didn't operate with binary code, and was reprogrammable to solve a complete range of computing problems. It was programmed using plug boards and switches, supporting input from of computing problems. It was programmed using plug boards and switches,  supporting input from an IBM cart reader,  and output to an IBM card punch.  It took up 167 square meters,  weighed 27 tons, and consuming 150 kilowatts of power.  It used throusands of 167 square meters,  weighed 27 tons,  and consuming 150 kilowatts of power.  It used thousands of vacuum tubes,  crystal diodes,  relays,, resistors,  and capacitors.  It could perform 5000 editions or 500 two digit multiplication in one second.  The ENIAC was so large that would occupy the big hall it had around 18000 vacuum tubes and consumed a large amount of electricity.