IBM 608
Encyclopedia
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.; (1991). IBM's 360 and early 370 systems. MIT Press. ISBN 0262161230. p.34 The 608 contained more than 3,000 germanium
transistor
s. Announced in April 1955, it was released in December 1957. It was similar in nature of operation to the vacuum tube
IBM 604
, which had been introduced a decade earlier. Although the 608 outpaced its immediate predecessor, the IBM 607 by a factor of 2.5, it was soon obsoleted by newer IBM products and only a few dozen were ever delivered. The 608 was withdrawn from marketing in April 1959.
The use of transistors was a significant departure from the previous IBM calculators of this line; the 608 also used magnetic core memory
, but was still programmed using a control panel
. The main memory of the 608 had could store 40 nine-digit numbers, and it had an 18-digit accumulator. In raw speed terms, it could perform 4,500 additions per second, it could multiply two nine-digit numbers, yielding an 18-digit result in 11 milliseconds, and it could divide an 18-digit number by a nine-digit number to produce the nine-digit quotient in 13 milliseconds. The 608 could handle 80 program steps.
In order to spur the adoption of transistor technology, shortly before the first IBM 608 shipped, Tom Watson directed that a date be set after which no new vacuum tube based products would be released. This decision constrained IBM product managers, which otherwise had the latitude to select components for their products, to make the move to transistors. As a result, the successor to the IBM 650
used transistors, and it became the IBM 7070
—the company's first transistorized stored-program computer
.
The chief designer of the circuits used in the IBM 608 was Robert A. Henle
, who later oversaw the development of emitter-coupled logic
(ECL) class of circuits. The development of the 608 was preceded by the prototyping of an experimental all-transistor
version of the 604. Although this was built and demonstrated in October 1954, it was not commercialized.
Germanium
Germanium is a chemical element with the symbol Ge and atomic number 32. It is a lustrous, hard, grayish-white metalloid in the carbon group, chemically similar to its group neighbors tin and silicon. The isolated element is a semiconductor, with an appearance most similar to elemental silicon....
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...
s. Announced in April 1955, it was released in December 1957. It was similar in nature of operation to the vacuum 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...
IBM 604
IBM 604
The IBM 604 was a control panel programmable Electronic Calculating Punch introduced in 1948, and was a machine on which considerable expectations for the future of IBM were pinned and in which a corresponding amount of planning talent was invested...
, which had been introduced a decade earlier. Although the 608 outpaced its immediate predecessor, the IBM 607 by a factor of 2.5, it was soon obsoleted by newer IBM products and only a few dozen were ever delivered. The 608 was withdrawn from marketing in April 1959.
The use of transistors was a significant departure from the previous IBM calculators of this line; the 608 also used magnetic core memory
Magnetic core memory
Magnetic-core memory was the predominant form of random-access computer memory for 20 years . It uses tiny magnetic toroids , the cores, through which wires are threaded to write and read information. Each core represents one bit of information...
, but was still programmed using 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...
. The main memory of the 608 had could store 40 nine-digit numbers, and it had an 18-digit accumulator. In raw speed terms, it could perform 4,500 additions per second, it could multiply two nine-digit numbers, yielding an 18-digit result in 11 milliseconds, and it could divide an 18-digit number by a nine-digit number to produce the nine-digit quotient in 13 milliseconds. The 608 could handle 80 program steps.
In order to spur the adoption of transistor technology, shortly before the first IBM 608 shipped, Tom Watson directed that a date be set after which no new vacuum tube based products would be released. This decision constrained IBM product managers, which otherwise had the latitude to select components for their products, to make the move to transistors. As a result, the successor to the IBM 650
IBM 650
The IBM 650 was one of IBM’s early computers, and the world’s first mass-produced computer. It was announced in 1953, and over 2000 systems were produced between the first shipment in 1954 and its final manufacture in 1962...
used transistors, and it became the IBM 7070
IBM 7070
IBM 7070 was a decimal architecture intermediate data processing system that was introduced by IBM in June 1960. It was part of the IBM 700/7000 series, and was based on discrete transistors rather than the vacuum tubes of the 1950s. It was the company's first transistorized stored-program...
—the company's first transistorized stored-program computer
Stored-program computer
A stored-program computer is one which stores program instructions in electronic memory. Often the definition is extended with the requirement that the treatment of programs and data in memory be interchangeable or uniform....
.
The chief designer of the circuits used in the IBM 608 was Robert A. Henle
Robert A. Henle
Robert A. Henle was an electrical engineer, who contributed to semiconductor technology.In 1949 he received the BSEE degree from the University of Minnesota....
, who later oversaw the development of emitter-coupled logic
Emitter-coupled logic
In electronics, emitter-coupled logic , is a logic family that achieves high speed by using an overdriven BJT differential amplifier with single-ended input, whose emitter current is limited to avoid the slow saturation region of transistor operation....
(ECL) class of circuits. The development of the 608 was preceded by the prototyping of an experimental 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. Although this was built and demonstrated in October 1954, it was not commercialized.
See also
- IBM Transistor Calculator Type 608 Manual of Operation – Preliminary Edition
- Unit record equipmentUnit record equipmentBefore the advent of electronic computers, data processing was performed using electromechanical devices called unit record equipment, electric accounting machines or tabulating machines. Unit record machines were as ubiquitous in industry and government in the first half of the twentieth century...
- History of IBMHistory of IBMInternational Business Machines, abbreviated IBM and nicknamed "Big Blue", is a multinational computer technology and IT consulting corporation headquartered in Armonk, New York, United States. The company is one of the few information technology companies with a continuous history dating back to...