“Manchester and Early Computers”

“Manchester and Early Computers”

• “Manchester and Early Computers”

Numerical Tables

Early adding machines

Charles Babbage

Analytical Engine - 1838

Babbage’s Analytical Engine

Arrival of Electronics

Colossus Codebreaking Machine

ENIAC Machine

Fixed Program Computer - 1940s

Stored Program Computer - 1940s

What is a True Computer?

• A list of instructions to manipulate numbers (e.g. “add”, “copy”, “test” or “remember”) to be carried out one instruction after another - “a Program”

• Instructions are represented by numbers, therefore a program can modify itself

• Needs a big memory to hold the program and the numbers

Need for Electronic “Memory”

Quest for a memory

• By 1945, several research teams were seeking a fast memory device.

• FC Williams and Tom Kilburn at Manchester University.

• During the war they had been expert radar engineers and they believed they could solve the memory problem using radar cathode ray tubes.

Freddie Williams and Tom Kilburn

Quest for a memory

• The Cathode Ray Tube Store could remember over 2000 binary digits by end of 1947

• But would it work in a computing machine?

• It needed to be tested “…in the hurly-burly of computing.”

The Need for Realistic Testing

• So they built a little computer to test their memory invention.

• Formally, it was: “The Small-Scale Experimental Machine”

• but informally: “Baby”

The Historic Event

• Monday, 21st June 1948, about 11:15

• The first time in the world that a stored-program computer worked

• The “Baby” was the World’s first Universal Computing Machine

• Nearly all modern computers are “like” that.

The Illustrated London News

The First program

Dots & Dashes

Interlude - What was happening elsewhere?

Cambridge - EDSAC

London - Pilot ACE

USA - von Neumann

IBM uses the Cathode Ray Tube store

Early Manchester Computers

Small-Scale Experimental Machine 1948 - Manchester

Illustrated London News photo with annotations

The Ferranti company gets involved

The Ferranti Mk 1 Computer - 1951

MEG - Ten times faster - 1954

Ferranti “Mercury” -1957

University Transistor Computer - 1953

Metro-Vick MV950 - 1956

University “MUSE” - 1958

University/Ferranti “ATLAS” - 1962

The Small-Scale Experimental Machine Rebuild Project

Project Goal

• “ To construct a working replica of the

• Manchester University

• Small-Scale Experimental Machine

• by Sunday, 21st June 1998

• the 50th anniversary of the successful running of the world's first stored computer program

• and to re-run that program. ”

SSEM - Building the Replica

• 1995 to June 1998 - 3½ years to do it all

• Fully sponsored by ICL - purchasing and use of workshops

• Acquire the obsolete parts, valves etc.

• Design studies - technical detective work

Dai Edwards’ Drawing of the Clock Circuit

Alec Robinson’s version of the Clock Circuit

Our Computer-Aided-Design version of the Clock Circuit

Illustrated London News Photo of Typewriter

The Mark 1 in 1949

Close-up of Mark 1 Typewriter

Cover of War Surplus Catalogue

Catalogue Page with Push Button Unit

Replica of the “Baby”

Small-Scale Experimental Machine Rebuild Project

• Thanks to:

• The University of Manchester for facilities and support

• Our sole sponsor - ICL, West Gorton

• The pioneer team for consultation and encouragement

• The Museum of Science and Industry for a final home

• Many individuals for information and parts

• My team of CCS members for their volunteer effort