- /A1 Photo of John Leech with "possibly Wim Klein (Dutch calculating prodigy)", 1953
- A/2 John Leech's unknown coding instructions, undated.
- A/3 Photo of machine. Presumably a Ferranti computer, 1953.
- A/4 Input routine for reading in tapes punched for Mk I, undated.
- A/5 Handwritten notes detailing collection contents compiled by Jennifer Leech, undated.
Historical and biographical material
- Reference
- GB 133 NAHC/HAS/A
- Dates of Creation
- 1953, n.d.