Notebook kept by Ernest Lenaerts during his work on the LEO computer, dated 9th October 1950 to 26th January 1951.

View the transcription for this notebook (opens as a separate document).

Includes entries:
NB04-001: 9 Oct 1950. Mechanical means for Dec/Binary Conversion
NB04-004: 16 Oct 1950 
NB04-007: 19 Oct 1950 [probably misdated]
NB04-009: 19 Oct 1950
NB04-011: 20 Oct 1950
NB04-012: 23 Oct 1950
NB04-013: 23 Oct 1950 (cont). Progress meeting
NB04-014: 23 Oct 1950 (cont) [taking notes in meeting, runs out of ink, changes to pencil]
NB04-017: 24 Oct 1950
NB04-018: 25 Oct 1950
NB04-019: 26 Oct 1950
NB04-020: 26-27 Oct 1950
NB04-024: 30 Oct 1950
NB04-027: 31 Oct 1950 
NB04-028: 2 Nov 1950 
NB04-029: Input/Output
NB04-030: [DIAGRAMS]
NB04-031: 7 Nov 1950. Coordinator
NB04-032: 7 Nov 1950  (cont) Gas Discharge Tubes
NB04-034: 8 Nov 1950 Pattern Registers
NB04-036: 8 Nov 1950 (cont) * [EL asterisked]
NB04-037: 9 Nov 1950
NB04-038: 21 Nov 1950
NB04-041: 21 Nov 1950 (cont). JMMP on the Converter  [DIAGRAM]
NB04-042: 21 Nov 1950 (cont). Time Scale Circuit  [DIAGRAM]
NB04-043: 21 Nov 1950 (cont). Decoder. Arithmetic Unit  [DIAGRAMS]
NB04-044: 21 Nov 1950 (cont). 'In doldrums again in spite of new fault sheet system that seems to work quite well'.
NB04-048: 23 Nov 1950 (cont). Possible Mod to CCUI
NB04-049: Control Circuits
NB04-050: 8 Dec 1950 and 11 Dec 1950. Testing of R & L Orders
NB04-051: 12 Dec 1950. Mods Required. Reconversion
NB04-052: 13 Dec 1950. [DIAGRAM]. Programme
NB04-053: 13 Dec 1950. [Allocating tasks to team members: Gibbs, Wheeler, Miss Cox & Miss P., Dutton, Shaw]
NB04-054: Method of testing Coder waveforms
NB04-055: 14 Dec 1950
NB04-057: 28 Dec 1950
NB04-059: 29 Dec 1950
NB04-061: 2 Jan 1951. Outlet annexe - JMMP
NB04-062: 2 Jan 1951 (cont). Mods to be done
NB04-063:  2 Jan 1951 (cont). Programming preparatory.  Immediate work
NB04-064:  4 Jan 1951. Suggestions for progress meeting
NB04-065:  4 Jan 1951 (cont). Possible dates
NB04-066:  4 Jan 1951 (cont). Secondary job (pending completion of EDSAC replica). Jobs after EDSAC replica ie during testing of HS I/O
NB04-067:  4 Jan 1951 (cont). What should a daily test programme do? [Meeting w TRT, Pinkerton, Kaye and Shaw]
NB04-068:  5 Jan 1951
NB04-070:  8 Jan 1951
NB04-073:  9 Jan 1951. Reconverter
NB04-075:  9 Jan 1951 (cont). Programme to simulate last part of TRT's programme
NB04-076:  10 Jan 1951. Programme for work on decoding
NB04-077:  10 Jan 1951 (cont). Mods
NB04-078:  11 Jan 1951. Reconverter
NB04-079:  11 Jan 1951 (cont). [DIAGRAM]
NB04-080:  19 Jan 1951. 'Since making the last diary note in this book much water has flowed '.
NB04-083:  22 Jan 1951. Programme for Monday
NB04-084:  22 Jan 1951  (cont). Pulse Techniques: FC Williams - Waveforms  [lecture notes?]
NB04-085:  22 Jan 1951  (cont). What could Babbage have used in place of waveform generator
NB04-087:  22 Jan 1951  (cont). [DIAGRAM]. Progress on Output  [mentions Hemy]
NB04-088:  25 Jan 1951 
NB04-090:  26 Jan 1951 
'I was wrong about the one simple fault […] there were three!'
NB04-092:  27 Jan 1951. [DIAGRAMS]
NB04-093:  26 Jan 1951  [probably misdated?]
NB04-094:  Saturday work

The Lenaerts notebooks are being digitised and transcribed as part of the National Lottery Heritage Funded LEO project at The Centre for Computing History.  We are indebted to our team of volunteers for scanning and transcribing the notebooks. If you would like to get involved with our work on these fascinating documents, please get in touch!

Provenance :
The notebooks are being digitised while on loan to The Centre for Computing History from the LEO Computers Society, with the kind permission of the Lenaerts family.