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The prototype computer (November 1953) had a simple seven-function order code and one track of 64 words for main storage. For the full-size computer (April 1955) the order code and storage were much extended and a hardware multiplier included. A third "regenerative" drum track formed an 8-word B
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that dramatically speed access to a small amount of data; thus the
Transistor Computer was slower than the Mark 1. Both versions had a pseudo 2-address (or 1+1) instruction format, where the address of the next instruction to be obeyed was contained within each instruction, to facilitate
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The expanded 1955 machine had a total of 200 point-contact transistors and 1300 point diodes, which resulted in a power consumption of 150 watts. There were considerable reliability problems with the early batches of transistors and the average error free run in 1955 was only 1.5 hours.
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became interested in the design after the success the university had selling computing time on the Mark I to commercial customers. They adopted the design of the 1955 Manchester
University transistor computer as the Metrovick 950. The only relevant experience in
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store. Arithmetic was serial, with a pulse rate of 125,000 per second. The instruction times were directly related to the 30-millisecond drum revolution time (the basic unit being the time to read a word, i.e. 1/64th of a revolution).
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of power, an astonishingly low figure in an era when machines typically used tens of kilowatts to warm their valves. The new model could add two 44-bit numbers in 1.5 drum revolutions, which, at a drum spin rate of 3000
171:, to the extent of six or seven machines, which were "used commercially within the company" or "mainly for internal use". The 950 appears to have been Metrovick's first and last commercial computer offering.
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first demonstrated their prototype transistorized computer using 92 point-contact transistors and 550 diodes in order to test the suitability of transistors in improving the reliability of the
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per addition. Although faster than the Mark I internally, the lack of
Williams tubes made it run much more slowly; the Mark I could add two 40-bit numbers in 1.8 milliseconds.
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in store was half a drum revolution, i.e., with 64 words on a track, 32 times the random access time for a word if it could be stored in a true
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and hardware multiplier. The added circuitry brought the machine to a total of 250 transistors. It used only 150
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was that in the early 1930s they had manufactured a mechanical calculating machine in the form of the
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Metropolitan-Vickers
Engineering Report on the Type 950 General Purpose Computer: Functional Design
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computer. This machine was similar to the Mark I, except that it did not include
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Second-generation computer made by
British company Metropolitan-Vickers
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1953 - Transistorized
Computers Emerge, Computer History Museum
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They changed all the circuits to more reliable types of
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History of science and technology in the United
Kingdom
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By 1955 the design was re-built with a Mark I-style
51:. Unsourced material may be challenged and removed.
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372:Tom Kilburn: A Pioneer of Computer Design
111:Learn how and when to remove this message
406:Early computers at Manchester University
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426:Transistorized computers
436:Early British computers
161:transistorized computer
322:Manchester University
314:differential analyser
190:Manchester University
431:Metropolitan-Vickers
341:Manchester computers
329:junction transistors
316:in conjunction with
310:Metropolitan-Vickers
305:Metropolitan-Vickers
188:and Douglas Webb of
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45:improve this article
370:David P. Anderson,
250:optimum programming
245:processor registers
175:Transistor Computer
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200:and used only the
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186:Richard Grimsdale
184:In November 1953
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269:accumulator
254:Accumulator
243:to provide
206:main memory
420:Categories
347:References
231:time to a
71:newspapers
180:Prototype
335:See also
167:company
101:May 2010
165:British
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85:scholar
266:B-line
159:was a
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92:JSTOR
78:books
233:word
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282:RPM
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214:kHz
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