Miscellaneous bundles of notes, calculations and narrative. These are almost entirely mathematical, one set being headed 'EMI 2400. Restricted Rational Fractions and Integers'.

Included with one bundle is a letter from Strachey to N. Brown (E.M.I.) October 1961: 'here are the machine language functions and the LISP functions for performing arithmetic on rational fractions'.

Copy of the official Design Specification for the EMIDEC 2400 computer, compiled by N. Brown, October 1961, and approved by C. Dain, November 1961. On the cover and title page the 2 and 00 are crossed out in the model number.

Miscellaneous narratives and notes on various topics, e.g. time-sharing, control strings, evaluation, etc.

Tagged folder of notes (various dates May-July 1962), with separate bundles and loose pages of notes (various dates October 1961-October 1962) all kept together, with a note by Strachey added. c.1973: 'LISP-like system. Probably for EMIDEC 2400?'.

Six-page typescript note 'Subroutines written for the LISP System', beginning 'In order that programming effort among those interested in the Strachey Lisp system may be coordinated...' (not by Strachey).

Folder of notes and calculations. An attempt to test Basic Language (BL) programs on other computers, including Pegasus, Orion, and Edsac II.

Five bundles of undated notes: 'Basic Language Structure' (B.L. sometimes L.B.) 'B-List C-List' 'List Program' 'General form of writing List programs' 'Define Macro'