Elliott 900 Series Computers

Documentation Archive

Last Update: 15 January 2021

Scanned copies of Elliott issued manuals and other Elliott 900 related documentation collected by Andrew Herbert.

All the documents contained in this archive are thought to be orphaned works and/or otherwise free of copyright restrictions. If this is not the case, the copyright owner is invited to contact me and ask for the copyright they hold to be acknowledged and/or have the relevant documents removed.

Elliott Issued Documents

920 Coral in Outline: Summary of facilities provided in the CAP Coral system for Elliott 920.

The Elliott 928 Graphical Display System, a brochure describing the Elliott 920 Graphical Display System and its software. The 928 display was designed to be driven by an Elliott 905 computer.

ACD Books: this folder contains books issued by (Marconi-) Elliott Airborne Computing Division (ACD). Specifically:

Elliott 900 Technical Manual, Copy No. 100, Vols. 1, 2, 3, 4: this folder contains the manual supplied by Elliotts to customers who purchased an Elliott 903 computer. It describes the hardware, peripherals, operating instructions, maintenance instructions and software. The content is primarily from Copy No. 100 belonging to an 8K Elliott 903 sold to The British Ceramics Research Association. Some missing / out-of-date pages have been added from other copies of the manual held by T.J. Froggatt and at The National Museum of Computing.

Elliott 903 ALGOL Design Documents: this folder contains the Elliott 903 Algol Design Documents authored by Don Hunter and Norman Spink. Specifically:

Elliott 905 computer brochure, Marconi Elliott Computer Systems Ltd, 1970: summary information about the Elliott 905 computer, software and peripherals.

Elliott 905 Digital Computer System Functional Specification, Issue 2, July 1969.

Elliott 920A Fact Book: a summary of the features of first machine in the Elliott 900 Series.

Elliott 920C computer brochure, Elliott Automation: summary brochure for Elliott 920C computer.

MC2/144 S.A.P. Symbolic Assembly Program: Section of Elliott 902 Computer Programming Manual, Part 2, Programming Languages describing assembly language for the Elliott 902 computer system (12 bit machine).

MCS 920B Computer Diagrams: this folder contains drawings issued by Elliott for 903 number 62, believed to be the 8K machine currently at the Centre for Computing History in Cambridge. It was originally sold the British Ceramics Research Association.

MCS 920B Manual MCB 143, Vol. 4 Technical Manual, Copy A.139, A/275: This folder contains parts 1-5 and Logic and Circuit Diagrams from the MCS 920B Technical Manual (parts 1-4 ex copy A.139, diagrams ex copy A.275). This substantially duplicates the 900 Technical Manual Volume 4, but includes sections on Additional Store and Power Supplies which are missing from the former, and more numerous and detailed diagrams making this a valuable volume when tracing and repairing hardware faults. It also describes some of the other power supplies and I/O devices available for the 920B when used as an embedded system.

MCS 920B Manual MCB 145, Vol. 5 Test Program Library, Copy A/117: Extracts from MCS 920B Manual, Vol. 5: Test Program Library MCB.145 Copy No. A/117 giving operating instructions for 920B test programs. The original also includes program coding sheets for each of the test programs but these have not been copies. Additional pages relating to X.51 and store tests for the 920M have been included.

Programming Compatibility of 920 Series Computers: Note written by Peter Lawrence describing differences between 920A, 920B and 920M models.

WORKSHOP: Elliott booklet describing the WORKSHOP calculator package.

Other Hardware Documents

Teletype BPRE Punch Manual: engineering manual for Teletype BPRE paper tape punch unit.

Teletype Manual: This folder contains the engineering manual for Teletype ASR teleprinter.

TRM 250 Tape Reader, Elliott Automation, 1967: technical manual for the Elliott 250 c/s paper tape reader including operating and maintenance instructions, mechanical design drawings and electronic circuit diagrams.

Other Software Documents

920ATC: notes by Terry Froggatt on 920ATC instruction set.

Aldenham Utilities: manual for Aldenham School Utilities.

AJH Algol

Bowdler-130782: notes on differences between BOWDLER 13/07/82 and version described in ACD Book 120 903 Utility Software.

City and Guilds Mnemonic Code

Integer Division: notes by Terry Froggatt on errors in the Elliott 903 Algol integer division code,


  • Documentation of FRED 9/2/71 a GPM-like symbol processor.

General Purpose Macrogenerator (GPM)

  • CJ GPM paper: a scanned copy of Strachey’s Computer Journal paper introducing GPM.
  • CCS Resurrection GPM Article: an article for Resurrection written by the author giving an account of the General Purpose Macrogenerator.


  • Algebra Manual 1970: manual for the Algebra system written in LOWL as a teaching aid for manipulating algebraic expressions.
  • K300 Computer Science Project: Harold Thimbleby’s writeup of his port of ML/I to the Elliott 905.
  • ML1 Manual: issue 4 of ML/I User Manual.
  • MLI at ECUA Meeting 760923: notes from meeting of Elliott Computer User’s Association on 26/9/76 when Thimbelby’s 905 ML/I was distributed.
  • Thimbleby Tapes Investigation: write up of investigation of paper tapes supplied by Harold Thimbleby and recovery of his port of ML/I and LOWL tool chain.

Music Programs

XSTORE: summary documentation for XSTORE, a store test program written by Terry Froggatt.

Miscellaneous Documents

920M Construction: short article describing construction techniques for Elliott 920M.

Benson-Lehner Plotter: An advertisement for the Benson-Lehner plotter for the Elliott 903.

CCS Resurrection Elliott 903 Software Article: an article for the CCS Resurrection magazine written by the author summarizing the software available for the Elliott 900 series.

Educational Computer: an article from the Computer Bulletin, December 1965 describing the use of an Elliott 903 computer for education.

Elliott 903 Operating Notes is a summary of entry points, data formats and error messages for the main Elliott 900 and ACD utilities.

Page Inventories This folder contains a summary of the pages in the base documents that were scanned to make this collection.