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The UNIVAC I (UNIVersal Automatic Computer I) was the first commercial computer made in the United States. It was designed by J. Presper Eckert and John Mauchly, the men behind the first American electronic computer, the ENIAC. During the years before successor models of the UNIVAC I appeared, the machine was simply known as "the UNIVAC".

The first UNIVAC was delivered to the United States Census Bureau on March 30, 1951 and was dedicated on June 14th that year.[1] The fifth (built for the Atomic Energy Commission) was used by CBS to predict the 1952 presidential election. With a sample of just 1% of the voting population it predicted that Eisenhower would win; something nobody would believe, but UNIVAC was right!

The UNIVAC I computers were built by Remington Rand's Univac-division (successor of the Eckert-Mauchly Computer Corporation (EMCC) , bought by Rand in 1950).

1 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 MHzA megahertz (MHz is one million (106) hertz, a measure of frequency. Megahertz in radio When used in the context of radio, MHz refers to the number of oscillations of electromagnetic radiation. Severel parts of the radio spectrum fall into the MHz range: clock. The mercuryMercury also called quicksilver is a chemical element in the periodic table that has the symbol Hg ( L. hydrargyrum and atomic number 80. A heavy, silvery, transition metal, mercury is one of only two elements that are liquid at room temperature (the othe delay line memoryDelay line memory was a form of computer memory used on some of the earliest digital computers, such as the EDSAC and UNIVAC I. The first such systems consisted of a column of mercury with piezo crystal transducers (a combination of speaker and microphone 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 ft² (35.5 m²) 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:

1. A channel in a column of mercury, with receiving and transmitting quartzFor other uses of this word, see Quartz (disambiguation). Milk quartz rock Quartz is the most abundant mineral on Earth (about 12% vol. It has a hexagonal crystal structure made of trigonal-crystallized silica (silicon dioxide, SiO), with a hardness of 7 crystalThis article is about the form of solid matter. For other uses of this word, see Crystal (disambiguation . Insulin Crystals A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extends mounted at opposite ends.
2. An intermediate frequency chassis, connected to the receiving crystal, containing amplifiers, detector, and compensating delay, mounted on the shell of the mercury tank.
3. 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.

Numbers were represented using excess-3Excess-3 binary coded decimal (XS-3) is a numeral system used in some old computers. In XS-3, numbers are represented as decimal digits, and each digit is represented by four bits as the BCD value plus 3 (the "excess" amount): Digit Bits Digit Bits 0 0011 binary coded decimal arithmetic with 6 bits per digit (and one parity bit per digit for error checking), allowing 11 digit signed magnitude numbers.