1951

MIT´s Whirlwind debuted on Edward R. Murrow´s "See It Now" television series. Project director Jay Forrester described the computer as a "reliable operating system," running 35 hours a week at 90-percent utility using an electrostatic tube memory.

Start of project:	1945
Completed:	1951
Add time:	.05 microseconds
Input/output:	cathode ray tube, paper tape, magnetic tape
Memory size:	2048 16-digit words
Memory type:	cathode ray tube, magnetic drum, tape (1953 - core memory)
Technology:	4,500 vacuum tubes, 14,800 diodes
Floor space:	3,100 square feet
Project leaders:	Jay Forrester and Robert Everett England´s first commercial computer, the Lyons Electronic Office, solved clerical problems. The president of Lyons Tea Co. had the computer, modeled after the EDSAC, built to solve the problem of daily scheduling production and delivery of cakes to the Lyons tea shops. After the success of the first LEO, Lyons went into business manufacturing computers to meet the growing need for data processing systems. The UNIVAC I delivered to the U.S. Census Bureau was the first commercial computer to attract widespread public attention. Although manufactured by Remington Rand, the machine often was mistakenly referred to as the "IBM UNIVAC." Remington Rand eventually sold 46 machines at more than $1 million each.F.O.B. factory $750,000 plus $185,000 for a high speed printer. Speed: 1,905 operations per second Input/output: magnetic tape, unityper, printer Memory size: 1,000 12-digit words in delay lines Memory type: delay lines, magnetic tape Technology: serial vacuum tubes, delay lines, magnetic tape Floor space: 943 cubic feet Cost: F.O.B. factory $750,000 plus $185,000 for a high speed printer Project leaders: J. Presper Eckert and John Mauchly

1950

Computers
ERA 1101 drum memory		Engineering Research Associates of Minneapolis built the ERA 1101, the first commercially produced computer; the company´s first customer was the U.S. Navy. It held 1 million bits on its magnetic drum, the earliest magnetic storage devices. Drums registered information as magnetic pulses in tracks around a metal cylinder. Read/write heads both recorded and recovered the data. Drums eventually stored as many as 4,000 words and retrieved any one of them in as little as five-thousandths of a second.

SEAC		The National Bureau of Standards constructed the SEAC (Standards Eastern Automatic Computer) in Washington as a laboratory for testing components and systems for setting computer standards. The SEAC was the first computer to use all-diode logic, a technology more reliable than vacuum tubes, and the first stored-program computer completed in the United States. Magnetic tape in the external storage units (shown on the right of this photo) stored programming information, coded subroutines, numerical data, and output.

SWAC		The National Bureau of Standards completed its SWAC (Standards Western Automatic Computer) at the Institute for Numerical Analysis in Los Angeles. Rather than testing components like its companion, the SEAC, the SWAC had an objective of computing using already-developed technology.

Pilot ACE		Alan Turing´s philosophy directed design of Britain´s Pilot ACE at the National Physical Laboratory."We are trying to build a machine to do all kinds of different things simply by programming rather than by the addition of extra apparatus," Turing said at a symposium on large-scale digital calculating machinery in 1947 in Cambridge, Mass. Start of project: 1948 Completed: 1950 Add time: 1.8 microseconds Input/output: cards Memory size: 352 32-digit words Memory type: delay lines Technology: 800 vacuum tubes Floor space: 12 square feet Project leader: J. H. Wilkinson

1949

Computers Wilkes with the EDSAC Maurice Wilkes assembled the EDSAC, the first practical stored-program computer, at Cambridge University. His ideas grew out of the Moore School lectures he had attended three years earlier. For programming the EDSAC, Wilkes established a library of short programs called subroutines stored on punched paper tapes. Technology: vacuum tubes Memory: 1K words, 17 bits, mercury delay line Speed: 714 operations per second

Manchester Mark I The Manchester Mark I computer functioned as a complete system using the Williams tube for memory. This University machine became the prototype for Ferranti Corp.´s first computer. Start of project: 1947 Completed: 1949 Add time: 1.8 microseconds Input/output: paper tape, teleprinter, switches Memory size: 128 + 1024 40-digit words Memory type: cathode ray tube, magnetic drum Technology: 1,300 vacuum tubes Floor space: medium room Project leaders: Frederick Williams and Tom Kilburn

People & Pop Culture Thomas Watson Jr., speaking to an IBM sales meeting, predicted all moving parts in machines would be replaced by electronics within a decade.

1948

IBM´s Selective Sequence Electronic Calculator computed scientific data in public display near the company´s Manhattan headquarters. Before its decommissioning in 1952, the SSEC produced the moon-position tables used for plotting the course of the 1969 Apollo flight to the moon.

Speed:	50 multiplications per second
Input/output:	cards, punched tape
Memory type:	punched tape, vacuum tubes, relays
Technology:	20,000 relays, 12,500 vacuum tubes
Floor space:	25 feet by 40 feet
Project leader:	Wallace Eckert Norbert Wiener published "Cybernetics," a major influence on later research into artificial intelligence. He drew on his World War II experiments with anti-aircraft systems that anticipated the course of enemy planes by interpreting radar images. Wiener coined the term "cybernetics" from the Greek word for "steersman." In addition to "cybernetics," historians note Wiener for his analysis of brain waves and for his exploration of the similarities between the human brain and the modern computing machine capable of memory association, choice, and decision making. Software & Languages Claude Shannon´s "The Mathematical Theory of Communication" showed engineers how to code data so they could check for accuracy after transmission between computers. Shannon identified the bit as the fundamental unit of data and, coincidentally, the basic unit of computation.

1947

The Williams tube won the race for a practical random-access memory. Sir Frederick Williams of Manchester University modified a cathode-ray tube to paint dots and dashes of phosphorescent electrical charge on the screen, representing binary ones and zeros. Vacuum tube machines, such as the IBM 701, used the Williams tube as primary memory.

Point-contact transistor

On December 23, William Shockley, Walter Brattain, and John Bardeen successfully tested this point-contact transistor, setting off the semiconductor revolution. Improved models of the transistor, developed at AT&T Bell Laboratories, supplanted vacuum tubes used on computers at the time.

1946

In February, the public got its first glimpse of the ENIAC, a machine built by John Mauchly and J. Presper Eckert that improved by 1,000 times on the speed of its contemporaries.

Start of project:	1943
Completed:	1946
Programmed:	plug board and switches
Speed:	5,000 operations per second
Input/output:	cards, lights, switches, plugs
Floor space:	1,000 square feet
Project leaders:	John Mauchly and J. Presper Eckert. An inspiring summer school on computing at the University of Pennsylvania´s Moore School of Electrical Engineering stimulated construction of stored-program computers at universities and research institutions. This free, public set of lectures inspired the EDSAC, BINAC, and, later, IAS machine clones like the AVIDAC. Here, Warren Kelleher completes the wiring of the arithmetic unit components of the AVIDAC at Argonne National Laboratory. Robert Dennis installs the inter-unit wiring as James Woody Jr. adjusts the deflection control circuits of the memory unit.

1945

John von Neumann wrote "First Draft of a Report on the EDVAC" in which he outlined the architecture of a stored-program computer. Electronic storage of programming information and data eliminated the need for the more clumsy methods of programming, such as punched paper tape — a concept that has characterized mainstream computer development since 1945. Hungarian-born von Neumann demonstrated prodigious expertise in hydrodynamics, ballistics, meteorology, game theory, statistics, and the use of mechanical devices for computation. After the war, he concentrated on the development of Princeton´s Institute for Advanced Studies computer and its copies around the world.

People & Pop Culture

On September 9th, Grace Hopper recorded the first actual computer "bug" — a moth stuck between the relays and logged at 15:45 hours on the Harvard Mark II. Hopper, a rear admiral in the U.S. Navy, enjoyed successful careers in academia, business, and the military while making history in the computer field. She helped program the Harvard Mark I and II and developed the first compiler, A-0. Her subsequent work on programming languages led to COBOL, a language specified to operate on machines of different manufacturers.

Software & Languages

Konrad Zuse began work on Plankalkul (Plan Calculus), the first algorithmic programming language, with an aim of creating the theoretical preconditions for the formulation of problems of a general nature. Seven years earlier, Zuse had developed and built the world´s first binary digital computer, the Z1. He completed the first fully functional program-controlled electromechanical digital computer, the Z3, in 1941. Only the Z4 — the most sophisticated of his creations — survived World War II.

1944

Harvard Mark-1 is completed. Conceived by Harvard professor Howard Aiken, and designed and built by IBM, the Harvard Mark-1 was a room-sized, relay-based calculator. The machine had a fifty-foot long camshaft that synchronized the machine’s thousands of component parts. The Mark-1 was used to produce mathematical tables but was soon superseded by stored program computers.

1943

Project Whirlwind begins. During World War II, the U.S. Navy approached the Massachusetts Institute of Technology (MIT) about building a flight simulator to train bomber crews. The team first built a large analog computer, but found it inaccurate and inflexible. After designers saw a demonstration of the ENIAC computer, they decided on building a digital computer. By the time the Whirlwind was completed in 1951, the Navy had lost interest in the project, though the U.S. Air Force would eventually support the project which would influence the design of the SAGE program.

1942

The Atanasoff-Berry Computer is completed. Built at Iowa State College (now University), the Atanasoff-Berry Computer (ABC) was designed and built by Professor John Vincent Atanasoff and graduate student Cliff Berry between 1939 and 1942. While the ABC was never fully-functional, it won a patent dispute relating to the invention of the computer when Atanasoff proved that ENIAC co-designer John Mauchly had come to see the ABC shortly after it was completed

1941

Konrad Zuse finishes the Z3 computer. The Z3 was an early computer built by German engineer Konrad Zuse working in complete isolation from developments elsewhere. Using 2,300 relays, the Z3 used floating point binary arithmetic and had a 22-bit word length. The original Z3 was destroyed in a bombing raid of Berlin in late 1943. However, Zuse later supervised a reconstruction of the Z3 in the 1960s which is currently on display at the Deutsches Museum in Berlin.

The first Bombe is completed. Based partly on the design of the Polish “Bomba,” a mechanical means of decrypting Nazi military communications during WWII, the British Bombe design was greatly influenced by the work of computer pioneer Alan Turing and others. Many bombes were built. Together they dramatically improved the intelligence gathering and processing capabilities of Allied forces. [Computers]

The Complex Number Calculator (CNC) is completed. In 1939, Bell Telephone Laboratories completed this calculator, designed by researcher George Stibitz. In 1940, Stibitz demonstrated the CNC at an American Mathematical Society conference held at Dartmouth College. Stibitz stunned the group by performing calculations remotely on the CNC (located in New York City) using a Teletype connected via special telephone lines. This is considered to be the first demonstration of remote access computing.

1939

Hewlett-Packard is Founded. David Packard and Bill Hewlett found Hewlett-Packard in a Palo Alto, California garage. Their first product was the HP 200A Audio Oscillator, which rapidly becomes a popular piece of test equipment for engineers. Walt Disney Pictures ordered eight of the 200B model to use as sound effects generators for the 1940 movie “Fantasia.”