1. (c) Chris BurtonSmall-Scale Experimental Machine1 The “Baby” Re-born ä Background to an historic event ä Why the replica was built ä How the replica was built ä Demonstration of the working machine

2. (c) Chris BurtonSmall-Scale Experimental Machine2 The Cathode Ray Tube Store ä FC Williams and Tom Kilburn ä How the store worked ä Kilburn’s important report - December 1947 ä The need for realistic testing

3. (c) Chris BurtonSmall-Scale Experimental Machine3 Freddie Williams and Tom Kilburn In 1950

4. (c) Chris BurtonSmall-Scale Experimental Machine4 Regenerating the information PICKUP PLATE AMPLIFIER DISCRIMINATING CIRCUIT

5. (c) Chris BurtonSmall-Scale Experimental Machine5 The Need for Realistic Testing The Small-Scale Experimental Machine ä Sufficient functionality to be “universal” ä Sufficiently simple for quick results ä Designed to be expandable in functionality and capacity ä Only one arithmetic operation - subtraction

6. (c) Chris BurtonSmall-Scale Experimental Machine6 Small-Scale Experimental Machine - schematic diagram

7. (c) Chris BurtonSmall-Scale Experimental Machine7 The Illustrated London News

8. (c) Chris BurtonSmall-Scale Experimental Machine8 The First Program ä Reliability gradually improved in June 1948 ä Kilburn’s program to find highest factor of a number ä It succeeded with a small number after a run of a few seconds at about 11.00 am on 21st June 1948

9. (c) Chris BurtonSmall-Scale Experimental Machine9 The First program From a notebook kept by Geoff Tootill

10. (c) Chris BurtonSmall-Scale Experimental Machine10 Dots & Dashes

11. (c) Chris BurtonSmall-Scale Experimental Machine11 The Historic Event ä The first time in the world that a stored- program computer worked ä Monday, 21st June 1948, about 11:15 ä The “Baby” was the World’s first Universal Computing Machine ä Nearly all modern computers are “like” that.

12. (c) Chris Burton12 The Computer Conservation Society The Small-Scale Experimental Machine Rebuild Project THE MUSEUM OF SCIENCE & INDUSTRY IN MANCHESTER

13. (c) Chris BurtonSmall-Scale Experimental Machine13 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.”

14. (c) Chris BurtonSmall-Scale Experimental Machine14 SSEM - Design Studies ä Key documents ä Analysis of circuits - e.g., Clock Chassis ä Analysis of photographs - e.g., Typewriter ä Chassis identification

15. (c) Chris BurtonSmall-Scale Experimental Machine15 Dai Edwards’ Drawing of the Clock Circuit

16. (c) Chris BurtonSmall-Scale Experimental Machine16 Our CAD clock circuit ä

17. (c) Chris BurtonSmall-Scale Experimental Machine17 Close up of Clock Chassis

18. (c) Chris BurtonSmall-Scale Experimental Machine18 Our Computer-Aided-Design Drawing of Chassis Metalwork

19. (c) Chris BurtonSmall-Scale Experimental Machine19 SSEM - Acquisition of Parts ä Key items - valves and cathode ray tubes ä Generosity of many individuals

20. (c) Chris BurtonSmall-Scale Experimental Machine20 The Mark 1 in 1949

21. (c) Chris BurtonSmall-Scale Experimental Machine21 Close-up of Mark 1 Typewriter

22. (c) Chris Burton Cover of War Surplus Catalogue

23. (c) Chris BurtonSmall-Scale Experimental Machine23 Catalogue Page with Push Button Unit

24. (c) Chris BurtonSmall-Scale Experimental Machine24 Five of the pioneer team in 1998 Tom Kilburn, Dai Edwards, Geoff Tootill, Tommy Thomas, Alec Robinson

25. (c) Chris BurtonSmall-Scale Experimental Machine25 50th Anniversary Kilburn and Tootill re-run the first program on 21st June 1998