ENIAC Vital Statistics * Physical Characteristics * 19,000 vacuum tubes, 1,500 relays * 60,000 pounds, 16,200 cubic feet * 174 kilowatts * 5 kflops (~ same as Intel 4004) * Future Prediction (1949 Popular Mechanics) * 1,500 vacuum tubes * 3,000 pounds * 10 kilowatts Previous slide Next slide Back to first slide View graphic version http://www.nationmaster.com/encyclopedia/UNIVAC-I Description UNIVAC I used 5,200 vacuum tubes, weighed 29,000 pounds (13 metric tons), consumed 125 kW, and could perform about 1,905 operations per second running on a 2.25 MHz clock. The mercury delay line memory unit alone was 14 feet by 8 feet by 8.5 feet high (4.3 m ´ 2.4 m ´ 2.6 m). The complete system occupied more than 350 ft· (35.5 m·) of floor space. The main memory is 1000 words of 11 decimal digits plus sign (72 bit words), consisting of 100 channels of 10 word mercury registers. The input and output memory is 120 words, consisting of 12 channels of 10 word mercury registers. There are 6 channels of 10 word mercury registers as spares. With modified circuitry, 7 more channels control the temperature of the 7 mercury tanks, and one more channel is used for the 10 word "Y" register. The total of 126 mercury channels is contained in the 7 mercury tanks mounted on the backs of sections MT, MV, MX, NT, NV, NX, and GV. Each mercury tank is divided into 18 mercury channels. Each 10 word mercury channel is made up of three sections: * A channel in a column of mercury, with receiving and transmitting quartz crystals mounted at opposite ends. * An intermediate frequency chassis, connected to the receiving crystal, containing amplifiers, detector, and compensating delay, mounted on the shell of the mercury tank. * A recirculation chassis, containing cathode follower, pulse former and retimer, modulator, which drives the transmitting crystal, and input, clear, and memory-switch gates, mounted in the sections adjacent to the mercury tanks. Instructions were 36 bits long, packed 2 per word. Numbers were represented using excess-3 binary coded decimal arithmetic with 6 bits per digit (and one parity bit per digit for error checking), allowing 11 digit signed magnitude numbers. History As well as being the first American commercial computer, the UNIVAC I was the first computer designed at the outset for business use. The first contracts were with government agencies, the Census Bureau, the United States Air Force, and the Army Map Service. Contracts were also signed by the A.C. Nielsen Company, and the Prudential Insurance Company. Following the sale of Eckert-Mauchly Computer Corporation to Remington Rand, due to the cost overruns on the project, Remington Rand convinced Nielsen and Prudential to cancel their contracts. After the first three UNIVAC I systems, two were sold to the Atomic Energy Commission, and one to the United States Navy. The seventh UNIVAC I was installed at the Remington Rand sales office in New York City. The eighth UNIVAC I, the first sale for business applications, was installed at the General Electric Appliance Division, to do payroll, in January, 1954. DuPont bought the twelfth UNIVAC I, it was delivered in September, 1954. Pacific Mutual Insurance received a UNIVAC I system in August, 1955. Other insurance companies soon followed. The Census Bureau got a second UNIVAC I in October 1954. Originally priced at $159,000, the UNIVAC I rose in price until they were between $1,250,000 and $1,500,000. The UNIVAC I was too expensive for most universities, and Sperry Rand was not strong enough financially to afford to give many away. However Sperry Rand donated UNIVAC I systems to Harvard University (1956), the University of Pennsylvania (1957), and Case Institute of Technology in Cleveland, Ohio (1957). A total of 46 UNIVAC I systems were eventually built and delivered. http://www.library.upenn.edu/exhibits/rbm/mauchly/jwm11.html John W. Mauchly and the Development of the ENIAC Computer The UNIVAC and the Legacy of the ENIAC ------------------------------------------------------------------------ The ENIAC's legacy was larger than just the UNIVAC computer built by the Eckert- Mauchly Computer Corporation. The SEAC, ILLIAC, Whirlwind and MANIAC--as well as von Neumann's computer built at the Institute for Advanced Studies in Princeton, New Jersey--were among the one-of-a-kind computers that succeeded the ENIAC. Seeing the potential in electronic digital computation, other private firms, including Engineering Research Associates and IBM, soon entered into the business of digital electronic computers. The backdrop of this panel recapitulates the technical lineage that led into the ENIAC and lists the series of computer systems that emerged in its wake. Photograph of UNIVAC, n.d. (click to expand to 83k) Merger agreement with Remington Rand, 15 February 1950. (click to expand to 165k) The development of a commercial computer proved too difficult for a start-up company. Although Mauchly and Eckert could produce an experimental machine in the confines of a laboratory, a standard commercial system run by trained operators rather than research engineers required further improvements in design and reliability. Problems concerning military security and the hostile attitude of certain influential academic advisors to the military made Eckert and Mauchly's job more difficult. Ultimately it was the cost of developing a commercial computer that led Eckert and Mauchly sold their company to Remington Rand in February of 1950. The first UNIVAC computer was delivered to the Census Bureau in June 1951. Unlike the ENIAC, the UNIVAC processed each digit serially. But its much higher design speed permitted it to add two ten-digit numbers at a rate of almost 100,000 additions per second. Internally, the UNIVAC operated at a clock frequency of 2.25 MHz, which was no mean feat for vacuum tube circuits. The UNIVAC also employed mercury delay-line memories. Delay lines did not allow the computer to access immediately any item data held in its memory, but given the reliability problems of the alternative Cathode Ray Tube (CRT) technology, this was a good technical choice. Photograph of J. W. Mauchly leaning over UNIVAC console. (click to expand to 83k) Article on use of UNIVAC to forecast 1952 presidential election results for CBS, from Philadelphia Evening Bulletin, 15 October 1952. Pres Eckert at center, Walte r Cronkite at right. (click to expand to 358k) Finally, the UNIVAC had placed strong emphasis on its input/output capabilities, being designed specifically for data processing applications such as that of the Census Bureau. In this connection, EMCC had developed a digital magnetic tape recording unit that could deliver data to the UNIVAC at a rate of 40,000 binary digits (bits) per second. For a brief period, Univac had captured a majority of the market for digital electronic computer systems. Illustration from cover of Remington Rand brochure on UNIVAC, n.d.. (click to expand to 110k) * Some pertinent web resources: (to return to this page afterward, hit the "back" button on your browser, usually at upper left) * Articles on UNIVAC's history since 1953 -- George Gray, Unisys History Newsletter. * Poster announcing the acquisition of a UNIVAC I by Sylvania --WGBH, Boston. [Introduction] [Previous panel] [Next panel] ------------------------------------------------------------------------ [an error occurred while processing this directive] [an error occurred while processing this directive] Last update: Monday, 03-Feb-2003 11:09:19 EST Send mail concerning this page to: shawcros@pobox.upenn.edu http://www.nationmaster.com/encyclopedia/ENIAC http://www.nationmaster.com/encyclopedia/Atanasoff-Berry-Computer Encyclopedia: Atanasoff Berry Computer Sponsored links: Atanasoff Berry Computer is the name applied, long after the fact, to an experimental machine for solving systems of simultaneous linear equations, developed in 1938-42 at Iowa State University by Dr. John Vincent Atanasoff and Clifford E. Berry. The Atanasoff-Berry Computer, constructed in the basement of the Physics building at Iowa State University, took over two years to complete. It was first demonstrated in November of 1939. The computer weighed more than seven hundred pounds (320 kg). It contained approximately 1 mile (1.6 km) of wire, 280 dual-triode vacuum tubes, 31 thyratrons, and was about the size of a desk. Because of the machine's innovative use of electronics for arithmetical calculation, it has been described as the first "electronic digital computer". However, it was a special-purpose, non-programmable "hard wired" machine, which distinguishes it from later, more general machines, such as the Z3, ENIAC, the Harvard Mark I, EDVAC, the University of Manchester designs, or Turing's post-War designs at NPL and elsewhere. The machine was, however, the first to implement three ideas that are still part of every modern computer: * Using binary digits to represent all numbers and data * Performing all calculations using electronics rather than wheels, rachets, or mechanical switches * Organizing a system in which computation and memory are separated. The machine was seen by John Mauchly in 1941, and is alleged to have influenced his later work on ENIAC. Mauchly denied this, but it was the basis for a court decision invalidating the ENIAC patents. The memory was a pair of drums, each containing 1600 capacitors that rotated on a common shaft once per second. The capacitors on each drum were organized into 32 "bands" of 50 (30 active bands and 2 spares in case a capacitor failed), giving the machine a speed of 30 additions/subtractions per second. Although the Atanasoff-Berry Computer was an important step up from earlier computing machines, it was not fully automatic. An operator was needed to operate the control switches in order for the computer to function properly. Unlike modern computers, the Atanasoff-Berry Computer was not programmable, however; it was the first computer to have separate sections for the memory and computation. Little did Dr. Atanasoff realize that his computer would change the lifestyle of billions of people across the globe. http://www.nationmaster.com/encyclopedia/IBM-360 http://www.nationmaster.com/encyclopedia/Supercomputer The distinction between supercomputers and mainframes is not a hard and fast one, but generally one can say that supercomputers focus on problems which are limited by calculation speed while mainframes focus on problems which are limited by Input/Output and reliability. As a consequence: * Supercomputers typically exploit massive parallelism, often with thousands of processors, while mainframes have a single or a small number (up to several dozen) of processors. * Because of the parallelism visible to the programmer, supercomputers are quite complicated to program; in mainframes, the limited parallelism (if present) is usually hidden from the programmer. * Supercomputers are optimized for complicated computations that take place largely in memory, while mainframes are optimized for simple computations involving huge amounts of external data accessed from databases. * Supercomputers tend to cater to science and the military, while mainframes tend to target business and civilian government applications. Sponsored links: Mainframes (often colloquially referred to as "big iron") are large, powerful, and expensive computers used mainly by large companies for bulk data processing (such as bank transaction processing). The term arose during the early 1970s with the introduction of smaller computers such as the DEC PDP series, which became known as minicomputers, so users coined the term "mainframe" to describe larger, earlier types. Description Modern mainframe computers' abilities are not so much defined by their CPU speed as by their massive internal memory, large, high-capacity external storage, fast high-throughput I/O, high-quality internal engineering and resulting proven reliability, and expensive but high-quality technical support. These machines can and do run successfully for years without interruption, with repairs taking place whilst they continue to run. Mainframe vendors offer such services as off-site redundancyÑif a machine does break down, the vendor offers the option to run customers' applications on their own machines (often without users even noticing the change) whilst repairs go on. Often, mainframes support thousands of simultaneous users who gain access through "dumb" terminals and early mainframes either supported this timesharing mode or operated in batch mode where users had no direct access to the computing service, it solely providing back office functions. At this time mainframes were so called because of their very substantial size and requirements for specialised HVAC and electrical power. Some mainframes have the ability to run (or "host") multiple operating systems and thereby operate not as a single computer but as a number of "virtual machines". In this role, a single mainframe can replace dozens or hundreds of smaller PCs, reducing management and administrative costs while providing greatly improved scalability and reliability. The reliability is improved because of the hardware redundancy noted above, and the scalability is achieved because hardware resources can be reallocated among the "virtual machines" as needed. This is much harder to do with PCs, because adding or removing hardware resources often requires the machine to be taken offline, and the hardware limitations are much more restrictive. When running as the host for many "virtual machines" a mainframe can provide the raw power for which they have always been valued, but also the flexibility provided by PC networks. Currently, IBM mainframes are dominant in the market, with Hitachi, Amdahl, and Fujitsu also producing machines. Prices start at several hundred thousand dollars. http://www.nationmaster.com/encyclopedia/Microcomputer http://www.nationmaster.com/encyclopedia/Minicomputer http://www.nationmaster.com/encyclopedia/Apple-Computer SGI's core market has traditionally been Hollywood special effects studios. http://www.nationmaster.com/encyclopedia/Silicon-Graphics,-Inc. http://www.nationmaster.com/encyclopedia/Workstation http://www.nationmaster.com/encyclopedia/Personal-Computer http://www.nationmaster.com/encyclopedia/Laptop http://foodtech.gatech.edu/news/onthespot_ustech.htm http://panuganty.tripod.com/articles/softwear.htm http://www.jegsworks.com/Lessons/lesson3/lesson3-3.htm - pointing devices http://www.jegsworks.com/Lessons/lesson3/lesson3-4.htm Below is the image in its original context on the page: http://www.cheap-hard-drives.com/internalcomps.htm