Ferranti Mercury
early commercial computer
The Mercury was an early commercial computer from the mid-1950s built by Ferranti. It was the successor to the Ferranti Mark 1, adding a floating-point unit for improved performance, and increased reliability by replacing the Williams tube memory with core memory and using more solid-state components. The computer had roughly 2000 vacuum tubes (mostly type CV2179/A2134 pentodes, EL81 pentodes and CV2493/ECC88 double triodes) and 2000 germanium diodes. Nineteen Mercuries were sold before Ferranti moved on to newer designs.
Predecessor: Mark I
When the Mark I started running in 1951, reliability was poor. The primary concern was the drum memory system, which frequently broke down. Additionally, the machine used 4,200 thermionic valves, mostly EF50 pentodes and diodes that had to be replaced constantly. The Williams tubes, used as random-access memory and registers, were reliable but required constant maintenance. As soon as the system went into operation, teams started looking at solutions to these problems.
One team decided to produce a much smaller and more cost-effective system built entirely with transistors.
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This entry incorporates text from “Ferranti Mercury” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.