The first computers used vacuum tubes for circuitry and magnetic drums for memory and
were often enormous, taking up entire rooms. They were very expensive to operate and in
addition to using a great deal of electricity, the first computers generated a lot of heat,
which was often the cause of malfunctions.
First generation computers relied on machine language, the lowest-level programming
language understood by computers, to perform operations, and they could only solve one
problem at a time, and it could take days or weeks to set-up a new problem. Input was
based on punched cards and paper tape, and output was displayed on printouts.
The UNIVAC and ENIAC computers are examples of first-generation computing devices.
The UNIVAC was the first commercial computer delivered to a business client, the U.S.
Census Bureau in 1951.
First Generation Computers