Computer ◆ Conservation ◆ Society

Ferranti Pegasus

The Pegasus computer was manufactured by Ferranti Ltd from 1955 to about 1962. About 40 systems were sold. It was popular with users because of its consistent and clean architecture. The machine used plug-in package construction, main store was a 4096- or 8128-word drum, computing store about 50 words of nickel acoustic delay lines, serial bit-rate 333 kc/S, 39-bit words, paper tape in and out.

See Resurrection issue 7 for an insight to some of the design decisions; and the paper The Design Philosophy of Pegasus, A Quantity Production Computer by W.S.Elliott et al in Proc.I.E.E. Vol 103, Part B, p188 published in 1956.

An emulator is available as follows:

32 64 which contains an emulator by Chris Burton written for MSDOS. Download the file into a folder C:\Pegem, and unzip it there. The .zip file contains both PEGEM (which is the original version of the emulator) and PegEm2 which adds support for the mouse and which is the reccommended version. The emulator manual (PEGEM.RTF) documents PEGEM, but there is a supplement (PegEm2-mouse.doc) which describes the additions present in PegEm2. There are known to be some minor bugs when run on current versions of Windows but it is useable in DOSBox.

Programming Manual.pdf the original guide to Pegasus programming written by George Felton. Kindly note that this is a very large file (39Mb) which may take some time. It is a scanned image rather than a text-based document. which contains documentation of the various library programs available for Pegasus (18Mb).

64 which contains auxilliary material for the emulator.