IBM 604
Encyclopedia
The IBM 604 was a control panel
Plugboard
A plugboard, or control panel , is an array of jacks, or hubs, into which patch cords can be inserted to complete an electrical circuit. Control panels were used to direct the operation of some unit record equipment...

 programmable Electronic Calculating Punch introduced in 1948, and was a machine on which considerable expectations for the future of IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

 were pinned and in which a corresponding amount of planning talent was invested. It could be considered a hybrid between an accounting machine
Accounting Machine
An accounting machine, or bookkeeping machine or recording-adder, was generally a calculator and printer combination tailored for a specific commercial activity such as billing, payroll, or ledger...

 and a modern general purpose computer like the IBM 701
IBM 701
The IBM 701, known as the Defense Calculator while in development, was announced to the public on April 29, 1952, and was IBM’s first commercial scientific computer...

 introduced in 1953.

Most of the circuitry was based on modifications of circuit designs used in the earlier 603 Electronic Multiplier
IBM 603
The IBM 603 Electronic Multiplier was the first mass-produced commercial electronic calculating device; it used vacuum tubes to perform multiplication and addition. The IBM 603 was adapted as the arithmetic unit in the IBM Selective Sequence Electronic Calculator. It was designed by James W. Bryce,...

 and was packaged in small one-tube
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...

-replaceable pluggable unit
Field Replaceable Unit
This article is primarily about FRUs in computers.A field replaceable unit is a circuit board, part or assembly that can be quickly and easily removed from a personal computer or other piece of electronic equipment, and replaced by the user or a technician without having to send the entire product...

s. The calculation unit contained 1,400 tubes. Clock speed was increased from the 603's rate of 35kHz to 50 kHz. The 604 performed fixed point
Fixed-point arithmetic
In computing, a fixed-point number representation is a real data type for a number that has a fixed number of digits after the radix point...

 addition, subtraction, multiplication and division using BCD arithmetic.

Initial versions supported 40 program steps, and this was soon expanded to 60. Processing was still locked to the reader/punch cycle time, thus program execution had to complete within the time between a punched card
Punched card
A punched card, punch card, IBM card, or Hollerith card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions...

 leaving the read station and entering the punch station.

The 604 and a modified version, the 605, were used as components of the Card Programmed Electronic Calculator
IBM CPC
The IBM Card-Programmed Electronic Calculator or CPC was announced by IBM in May 1949. Later that year an improved machine, the CPC-II was also announced.The original CPC Calculator had the following machines interconnected by cables:...

s (CPC and CPC II). The 604 was also a component of the Test Assembly, a precursor to IBM's early computers.

An all-transistor
Transistor
A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...

 version of the 604 was built and demonstrated in October 1954. Although it used 2000 transistors as opposed to 1250 tubes in the original, it occupied only half the volume, and used only 5% as much power. This was only an experimental machine, but its technology was used to build the IBM 608
IBM 608
The IBM 608 was the first IBM product to use transistor circuits without any vacuum tubes and is believed to be the world's first all-transistorized calculator to be manufactured for the commercial market.Pugh, Emerson W.; Johnson, Lyle R.; Palmer, John H.; . IBM's 360 and early 370 systems. MIT...

, which shipped in December 1957, and was the first solid-state computing product to be commercialized.

An IBM 604 is preserved at the American Computer Museum
American Computer Museum
The American Computer Museum is a museum of the history of computing located in Bozeman, Montana, USA. It was founded in May 1990 by Barbara and George Keremedjiev as a non-profit organization. The museum was originally intended to have been located in Princeton, New Jersey, but the location was...

.

External links

Contains about 4 pages of IBM 604 survey detail: applications, customers, specifications, and costs.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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