LEO Catalogue Update: 6th December 2021

6th December 2021

Since our previous update there has been a development in regards to the LEO project.  


New Project Archivist

Luke Thorne has recently been appointed to the role of Project Archivist and has been overseeing the LEO project since late September; picking up where Jude Brimmer left off. Luke qualified as an Archivist in 2019 and has since been working for the Linnean Society of London as a part-time Assistant Archivist, which he continues to do alongside working for the Centre for Computing History. Since starting on the project he has been learning about the history and scope of the collection, and has proceeded with cataloguing and digitising material.


The following material has now been scanned, catalogued and uploaded:


LEO COMPUTERS SOCIETY COLLECTION – Research papers and programming

The first items that were catalogued, scanned and uploaded by Luke included material for the LEO Computers Society Collections, which were generously donated by Hamish Archibald. The material donated features some unpunched Hollerith Punch cards, two case studies about the uses for the LEO computer and a copy of the syllabus for a programmers and operators training course with lecture notes which were made by Hamish. We hope that these last items will be particularly insightful for anyone who wants to find out more about how programmers and operators were trained and what they learnt about. 

CMLEO/LS/EP/66103 - Hollerith Punch Cards 

CMLEO/LS/RC/19570701 - The LEO Computer: A case study in the use of an electronic computer in routine clerical work [Image not available at this time due to the publication being copyrighted and permission from the copyright holder is needed]

CMLEO/LS/RC/196104 - The application of a digital computer to the pre-operational problems of programming the extraction and supply of iron ore 

CMLEO/LS/MN/PRG/195701 - Fundamental Course of Training for Programmers & Operators Syllabus 

CMLEO/LS/MN/PRG/19570107 - Fundamental Course of Training for Programmers & Operators Notes 


David Caminer Papers – LEO Jobs – L3 Bakery Sales and Valuations 

Lots of material from David Caminer’s papers has been catalogued and uploaded for public viewing, including memoranda relating to the first job LEO performed for the Cadby Hall Bakeries to coincide with the 70th anniversary marking when LEO first became operational. Of particular interest are the reports on the initial run of the P1, P2 and P3 programmes (CMLEO/DC/WF/LL3/18).

CMLEO/DC/WF/LL3/1 - Notes by David Caminer 

CMLEO/DC/WF/LL3/2 - Letter from Peter Blackaby to David Caminer 

CMLEO/DC/WF/LL3/3 - Photocopied Memos from the Bakery Sales and Valuations Job 

CMLEO/DC/WF/LL3/4 - Bakery Sales and Valuations Job Correspondences List 

CMLEO/DC/WF/LL3/5 - Use of Electronic Calculator on a Clerical Job with only slow speed reading and recording 

CMLEO/DC/WF/LL3/6 - Memo regarding experiment to use LEO for the Cadby Hall Bakeries Valuation Job, 4th June 1951 

CMLEO/DC/WF/LL3/7 - Bakery Sales Valuations: Timetable and Method Summary 

CMLEO/DC/WF/LL3/8 - Specimen Forms 1-10 

CMLEO/DC/WF/LL3/9 - P1/3 – Bakery Valuations: Estimated Tape Lengths and Diameters 

CMLEO/DC/WF/LL3/10 - P1/3 – Bakery Sales Valuations: Perforating and checking current data 

CMLEO/DC/WF/LL3/11 - P2 – Controlling Perforation of Channel Sales Data 

CMLEO/DC/WF/LL3/12 - P3 – Controlling Perforation of Bakery Output Etc 

CMLEO/DC/WF/LL3/13 - Preparation of Data Tapes 

CMLEO/DC/WF/LL3/14 - P1 – Controlling Preparation of Amendment Data 

CMLEO/DC/WF/LL3/15 - C.H. Bakeries Cost Valuations P/e, 30th Sep 1951 

CMLEO/DC/WF/LL3/16 - Calculation of Sales Statistics for Cadby Hall Bakeries 

CMLEO/DC/WF/LL3/17 - Calculator Bakery Job 

CMLEO/DC/WF/LL3/18 - Reports on carrying out of Bakery Valuations job, October 1951 to January 1952 

CMLEO/DC/WF/LL3/19 - P1/3 for Data W/E 16th Nov 

CMLEO/DC/WF/LL3/20 - Investigation of queries concerning LEO Job P1/P3 for W/E [Week-Ending], 24.11.51 

CMLEO/DC/WF/LL3/21 - Memo regarding P1/3 Bakery Valuations, 13th December 1951 

CMLEO/DC/WF/LL3/22 - Memo regarding valuation of Output sheets, 21st December 1951 

CMLEO/DC/WF/LL3/23 - Memo regarding LEO – Bakery Sales and Output, 28th December 1951 (Copy) 

CMLEO/DC/WF/LL3/24 - Valuation Rates Sheets 

CMLEO/DC/WF/LL3/25 - Note on complications due to Bakery 1 following Bakery 17 (P/E 12.1.52) 

CMLEO/DC/WF/LL3/26 - Memo regarding Segregation of Frontshop and Backshop Results, 24th March 1952 

CMLEO/DC/WF/LL3/27 - Memo regarding P1/3 for March Q/E. Period, 27th March 1952 

CMLEO/DC/WF/LL3/28 - Memo regarding Error on P3 for 24th May, 4th June 1952 

CMLEO/DC/WF/LL3/29 - Memo regarding Bakery Job notification request, 24th July 1952 (Copy) 

CMLEO/DC/WF/LL3/30 - Memo regarding Bakery Job notification request, 29th July 1952 

CMLEO/DC/WF/LL3/31 - Memo regarding Jobs P1, 2 & 3, 1st August 1952 

CMLEO/DC/WF/LL3/32 - Memo regarding Bakery Stock Valuation Sheets, 12th September 1952 

CMLEO/DC/WF/LL3/33 - Memo regarding Bakery Valuations Job P 1/3 report and difficulties encountered, 18th September 1952 

CMLEO/DC/WF/LL3/34 - Memo regarding work to be carried out by LEO, 9th January 1953 (Copy) 

CMLEO/DC/WF/LL3/35 - Memo regarding notes for the Bakery Output Job, 12th January 1953 

CMLEO/DC/WF/LL3/36 - Job Requirements: Cadby Hall Bakeries Trading Analysis 

CMLEO/DC/WF/LL3/37 - Memo regarding Emergency Issue Notes and Advance Orders, 3rd November 1953 

CMLEO/DC/WF/LL3/38 - Memo regarding P1/2 Jobs, 9th November 1953 


M1 Job Surveys 

The next file from David Caminer’s papers features considerations and proposals put forward by Lyons employees about various jobs LEO could be used in and includes notes, calculations and correspondence.

CMLEO/DC/WF/LM1/1 - M1 Job Surveys 


Programming the LEO computer

More notes, instructions and flowcharts related to the programming and application of LEO have also been catalogued and uploaded.

CMLEO/DC/WF/PRG/C09 - C9. Self-checking codes on LEO 

CMLEO/DC/WF/PRG/C03 - C3. Programming sequences (Miscellaneous)

CMLEO/DC/WF/PRG/C70 - C70. LEO (Synthesis Orders) 

CMLEO/DC/WF/PRG/C04 - C4. Trial Technique 

CMLEO/DC/WF/PRG/FC3 - LEO Flowcharts – tracings (S11 – M5T) 


CMLEO/DC/WF/LL1 - LEO Jobs – L1 Payroll

Finally, we have catalogued and uploaded documentation related to the LEO’s operation during the L1 payroll job to calculate employees payroll. Includes notes, memos, reports and job analysis sheets.

CMLEO/DC/WF/LL1/1 - LEO Charges (L.1.)

CMLEO/DC/WF/LL1/2 - LEO Charges (L.2.)

CMLEO/DC/WF/LL1/3 - LEO Charges (L.4.)

CMLEO/DC/WF/LL1/4 - LEO Charges (L.8.)

CMLEO/DC/WF/LL1/5 - L1 Payroll: Programme Changes

CMLEO/DC/WF/LL1/6 - Memo approving reduction of charging rate, 5th October 1955

CMLEO/DC/WF/LL1/7 - Memo regarding projected reduction of charging rate for L1, 23rd September 1955

CMLEO/DC/WF/LL1/8 - L1: Costs

CMLEO/DC/WF/LL1/9 - LEO Wages Costs

CMLEO/DC/WF/LL1/10 - Memo regarding credit and debit, 17th June 1955

CMLEO/DC/WF/LL1/11 - Memo regarding LEO charge increase, 26th April 1955

CMLEO/DC/WF/LL1/12 - L1 Payroll - Cost Comparison

CMLEO/DC/WF/LL1/13 - LEO Job Cost Statement (Schedule A)

CMLEO/DC/WF/LL1/14 - LEO Job Cost Statement (Schedule B)

CMLEO/DC/WF/LL1/15 - Memo regarding the standard charge per employee, 7th January 1955

CMLEO/DC/WF/LL1/16 - L1: Standard charge per Employee

CMLEO/DC/WF/LL1/17 - LEO Payroll - Kitchens & Bakeries

CMLEO/DC/WF/LL1/18 - Cadby Hall Kitchens Payroll (L.13)

CMLEO/DC/WF/LL1/19 - LEO N.I. Schedules

CMLEO/DC/WF/LL1/20 - LEO N.I. Schedules Correction

CMLEO/DC/WF/LL1/21 - Revised LEO costing

CMLEO/DC/WF/LL1/22 - Clerical Costs

CMLEO/DC/WF/LL1/23 - Memo regarding revised costs and using 2 card feeds, 19th January 1954

CMLEO/DC/WF/LL1/24 - Summary of costs for Cadby Hall Bakeries Payroll and method comparison schedules



Find out more about our Heritage Lottery-funded LEO project here:

Welcome to LEO

Posted by: Luke




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