First Generation (1939-1954) - vacuum tube

1937 - John V. Atanasoff designed the first digital electronic computer
1939 - Atanasoff and Clifford Berry demonstrate in Nov. the ABC prototype
1941 - Konrad Zuse in Germany developed in secret the Z3
1943 - In Britain, the Colossus was designed in secret at Bletchley Park to decode German messages
1944 - Howard Aiken developed the Harvard Mark I mechanical computer for the Navy
1945 - John W. Mauchly and J. Presper Eckert built ENIAC at U of PA for the U.S. Army
1946 - Mauchly and Eckert start Electronic Control Co., received grant from National Bureau of Standards to build a ENIAC-type computer with magnetic tape input/output, renamed UNIVAC in 1947 but run out of money, formed in Dec. 1947 the new company Eckert-Mauchly Computer Corporation (EMCC).
1948 - Howard Aiken developed the Harvard Mark III electronic computer with 5000 tubes
1948 - U of Manchester in Britain developed the SSEM Baby electronic computer with CRT memory
1949 - Mauchly and Eckert in March successfully tested the BINAC stored-program computer for Northrop Aircraft, with mercury delay line memory and a primitive magentic tape drive; Remington Rand bought EMCC Feb. 1950 and provided funds to finish UNIVAC
1950- Commander William C. Norris led Engineering Research Associates to develop the Atlas, based on the secret code-breaking computers used by the Navy in WWII; the Atlas was 38 feet long, 20 feet wide, and used 2700 vacuum tubes
1951 - S. A. Lebedev developed the MESM computer in Russia
1951 - Remington Rand successfully tested UNIVAC March 30, 1951, and announced to the public its sale to the Census Bureau June 14, 1951, the first commercial computer to feature a magnetic tape storage system, the eight UNISERVO tape drives that stood separate from the CPU and control console on the other side of a garage-size room. Each tape drive was six feet high and three feet wide, used 1/2-inch metal tape of nickel-plated bronze 1200 feet long, recorded data on eight channels at 100 inches per second with a transfer rate of 7,200 characters per second. The complete UNIVAC system weighed 29,000 pounds, included 5200 vacuum tubes, and an offline typewriter-printer UNIPRINTER with an attached metal tape drive. Later, a punched card-to-tape machine was added to read IBM 80-column and Remington Rand 90-column cards.
1952 - Remington Rand bought the ERA in Dec. 1951 and combined the UNIVAC product line in 1952: the ERA 1101 computer became the UNIVAC 1101. The UNIVAC I was used in November to calculate the presidential election returns and successfully predict the winner, although it was not trusted by the TV networks who refused to use the prediction.
1954 - The SAGE aircraft-warning system was the largest vacuum tube computer system ever built. It began in 1954 at MIT's Lincoln Lab with funding from the Air Force. The first of 23 Direction Centers went online in Nov. 1956, and the last in 1962. Each Center had two 55,000-tube computers built by IBM, MIT, AND Bell Labs. The 275-ton computers known as "Clyde" were based on Jay Forrester's Whirlwind I and had magnetic core memory, magentic drum and magnetic tape storage. The Centers were connected by an early network, and pioneered development of the modem and graphics display.

First Generation (1939-1954) - vacuum tube Computer01

Atanasoff-Berry Computer 1939, from IEEE

First Generation (1939-1954) - vacuum tube PDRM1322a

magnetic drum memory of the Atanasoff-Berry Computer 1939, from Smithsonian NMAH

First Generation (1939-1954) - vacuum tube Computer03

Whirlwind core memory 1951, from IEEE

First Generation (1939-1954) - vacuum tube Computer02

first computer bug 1945, from IEEE

First Generation (1939-1954) - vacuum tube PDRM1348

UNIVAC 1951, from Smithsonian NMAH

First Generation (1939-1954) - vacuum tube Univac01

UNIVAC I ca. 1955, from Smithsonian

First Generation (1939-1954) - vacuum tube 86387

UNIVAC ad 1955/01/17 from Time

First Generation (1939-1954) - vacuum tube 86397

UNIVAC ad 1955/02/28 from Time

UNIVAC I of 1951 was the first business computer made in the U.S. "Many people saw a computer for the first time on television when UNIVAC I predicted the outcome of the 1952 presidential elections."

First Generation (1939-1954) - vacuum tube PDRM1325

First Generation (1939-1954) - vacuum tube PDRM1326

First Generation (1939-1954) - vacuum tube PDRM1327

Bendix G-15 of 1956, inexpensive at $60,000, for science and industry but could also be used by a single user; several hundred were built - used magnetic tape drive and key punch terminal

First Generation (1939-1954) - vacuum tube PDRM1330

First Generation (1939-1954) - vacuum tube PDRM1329

First Generation (1939-1954) - vacuum tube PDRM1331

First Generation (1939-1954) - vacuum tube PDRM1332

IBM 650 that "became the most popular medium-sized computer in America in the 1950's" - rental cost was $5000 per month - 1500 were installed - able to read punched cards or magnetic tape - used rotating magnetic drum main memory unit that could store 4000 words, from Smithsonian NMAH

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