The computer has evolved from a large-sized simple calculating machine to a smaller but much more powerful machine. The evolution of computer to the current state is defined in terms of the generations of computer. Each generation of computer is designed based on a new technological development, resulting in better, cheaper and smaller computers that are more powerful, faster and efficient than their predecessors.
First Generation (1937 to 1953): using VACUUM TUBES
The first generation of computers used vacuum tubes as the basic component for memory and circuitry for CPU, although there were also first generation computers that made use of relays and switches. Punched cards, paper tape and the magnetic tape were used as input and output devices. The instructions were written in machine language. Machine language uses 0s and 1s for coding of the instructions
Disadvantages:
- The vacuum tubes produced a lot of heat and consumed so much energy therefore was very expensive and could be afforded only by very large organizations.
- These computers were very large in size and non-portable.
- These computers were very slow, non-versatile, very faulty and not very reliable.
ATANASOFF-BERRY COMPUTER (1939): John Atanasoff and Clifford Berry at Iowa State College designed the first electronic computer. The project incorporated binary arithmetic and electronic switching.
COLUSSUS (1943): Alan Turing designed the machine for the British Military. It was the world’s first vacuum tube programmable logic calculator. This machine played an important role in breaking Nazi codes during World War II.
MARK I (1944): The first programmable digital computer made in the US was built as a partnership between Harvard University led by designer Howard Aiken and the company IBM. It was constructed out of switches, relays, rotating shafts and clutches. It weighed 5 tons, incorporated 500 miles of wire, 8 feet tall and 51 feet long.
ENIAC ~ Electronic Numerical Integrator and Computer (1946): The first general purpose programmable electronic computer was built by two American professors from the University of Pennsylvania ~ John Mauchly and J. Presper Eckert. They got funding from the American military to create a machine that would calculate firing tables for the army’s artillery guns. It weighed 30 tons, included 18,000 vacuum tubes, 6,000 switches and 1,500 relays.
EDVAC ~ Electronic Discrete Variable Automatic Computer (1950): EDVAC was a follow-up to ENIAC. Built by the same people – Mauchly and Presper Eckert, at the University of Pennsylvania, EDVAC’s conceptual design was to use the stored program concept introduced by John von Neumann. Instead of decimal numbers, EDVAC used binary. Like ENIAC, this machine was also funded by the US Army’s Ballistics Research Laboratory. It weighed 7,850 kg, included 6,000 vacuum tubes, 12,000 diodes, consumed 56W of power and covered 490 ft² of floor.
EDSAC ~ Electronic Delay Storage Automatic Computer (1949): EDSAC was developed by a group of scientists, headed by Professor Maurice V. Wilkes at Cambridge University. It was also based on the stored program concept and was one of the first to use binary digits. The input and output were provided by a paper tape.
Two groups of individuals were working at the same time to develop a stored program computer. In the US, at the University of Pennsylvania, EDVAC was being worked on. EDSAC finished ahead by 2 months and won the race as THE FIRST STORED PROGRAM COMPUTER. It was also the computer that ran the first graphical game nicknamed “BABY.”
EDSAC had 3,000 vacuum valves arranged on 12 racks and used tubes filled with mercury. It could carry out 650 instructions per second and occupied a room which measured 5 meters by 4 meters.
UNIVAC ~ Universal Automatic Computer (1951): The first commercially successful electronic computer, UNIVAC was also the first general purpose computer designed to handle both numeric and textual information. It was also designed by the same American professors who created ENIAC and EDVAC – John Mauchly and J. Presper Eckert. It was used for the analysis of the 1952 US Presidential Election. It was 8 feet high, 15 feet long and weighed 5 tons. It contained 5,600 tubes, 18,000 crystal diodes and 300 delays. A magnetic tape was used for data input and output.
