The Jim Austin Computer Collection

Ferranti Pegasus 2

 

The collection contains a set of important parts from a Pegasus computer. This was a valve based computer developed by Ferranti Ltd. around 1956. The collection contains all the input output elements of the machine. It was bought from a dealer in Edinburgh in Dec 2002.

 

The parts are in very good condition. The collection consists of machine number 23 (of 40 made) used by Bruce Peebles & co Ltd. in Edinburgh and is from a Pegasus 2 machine installed in October 1960. This is from information in 'The Pegasus Story' by Simon Lavington, 2000, a London Science Museum publication. The book contains a full account of this machine.

 

The parts consist of:

 

Monitor Panel (shown above). 20 Dec 1959.

Programmers Control Panel (shown below the monitor panel above). Dated 20 Aug 1959.

Drum store control panel. Dated 9 April 196X.

 

The Pegasus Programming Manual, G E Felton, Ferranti Ltd, 1962. The full operation manual for the machine.

 

Creed Model 75 Teleprinter.

Creed output printer/transmitter GP1 ARR 3.

Creed automatic transmitter 6S/6M.

Box of Creed spares.

Creed Power Unit.

 

Manuals:

Creed Teleprinter 75: instruction book, 1962, parts manual, technical description, operators manual.

Teletype ordering information 1962.

Ferranti high speed tape reader 1959 technical manual.

Creed Cam Unit Type 3 parts 1955.

Teletype Corporation parts high speed tape punch set 1960.

 

Note that a simulator for the machine can be found here

ftp://ftp.cs.man.ac.uk/pub/CCS-Archive/simulators/Pegasus

 

 

Pictures of one of these machines in use, the clock was a major feature of all these machines as was the operators panel showing two oscilloscope screens.

 

 

 

 

       

These pictures show a Pegasus machine in use at Newcastle University.

 

The lady in the Picture is Elizabeth Barraclough, this is what she said about the machine (Jan 2009):

 

It was my first machine! I remember it intimately, I had had experience of the Pegasus in the aircraft industry before I came to Newcastle in 1957. The University of Durham was about to get a Pegasus which was to be housed in Kings College Newcastle which at that time was a college of Durham so we were providing a service for the whole university and users from Durham had to travel 17 miles to Newcastle.
 
The machine had 'coachwork by Mulliners' the Rolls Royce body suppliers. Initially we had 2 paper tape readers and punched tape as output. It was quite reliable, one of the big jobs we did was student registration and produced an alphabetical list of students by sorting as many records as we could hold in the store (4K 39bit words) and outputting to paper tape. We then merged two paper tpae streams to one punched paper tape and so it continued. We worked overnight to do it and at one point the then Director, Ewan Page, was found virtually buried in paer tape having fallen asleep.
 
Its other claim to fame was that it was the last, or only, completely defined machine it had a 6 bit instruction code which was used as two octal digits ie 00 to 77 and everyone was defined for all the possible storage designations in the rest of the instruction. I think it was Pegasus that had trouble with division by zero and produced wrong answers. All the programs were put in on paper tape and those of us in charge rapidly learnt to read the first sequence which was E2.5 ie Enter at location 2.5.
 
Some interesting work was done on that machine, we had a philosopher designing Hi-Fi system, a botanist predicting the spread of primroses along hedges, physicists getting the next number in an equation. The people who were slow to use it were the engineers and even slower the medics. They all got there in the end.

 

Forgot to say anything about the scopes, they were really an engineers tool they could look at the binary contents of any 39 bit word, I don't remember using them for debugging programs.

 

 

 

 

Note the following recollection from Pete Turnbull, York, Sept 2007.

 

Yours belonged to Bruce Peebles (later Parsons Peebles) in Edinburgh. They were large-scale electrical engineers, the biggest employer in the north-east of Edinburgh, made big generators and high voltage (as in national grid) stuff, and had a test lab with a 750kV (or so) Van der Graaf generator for testing, and had a computer. Or so I discovered when I went on a day-long careers visit when I was at school. I've actually seen your Pegasus running, though I don't recall details :-)

Pete.

 

Last updated 11/01/2009