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Update Log

This page aims to keep a log of changes and updates to the pages on the 50th Anniversary Celebrations, Mark1 and Virtual Museum. The information is ordered by date; use the list below to jump straight to the changes made since you last looked.

1997 Sep Oct Nov 10th Dec 12th Dec 18th Dec
1998 8th Jan 12th Jan 22nd Jan 19th Feb 11th Mar 17th Mar
27th Mar 3rd Apr 23rd Apr 3rd May 14th May 29th May 16th Jun
3rd Jul 9th Jul 21st Aug 9th Nov 20th Nov 25th Nov 2nd Dec 18th Dec
1999 16th Feb 16th Mar 6th Apr 5th May 20th Aug 31st Aug
2000 12th Feb 31st May 15th Oct
2001 17th Jan 20th May 7th Oct
2003 3rd Nov, 16th Nov, 24th Nov
2005 30th Mar

September 1997

Before September there were two sets of pages, the pages on the Mark 1 (on and the pages on the history of the machines designed at Manchester University up to 1975 (on The top Mark 1 page gave a preview of the 1998 celebrations. The Mark 1 set was created by Joanne Allison based on material researched by Dr. Ian Cottam. The other set, The Virtual Museum of Manchester Computing, was researched and created by Kulwinder Gill in an undergraduate 3rd Year Project. Ian, Joanne and Kulwinder have all since left the department, and the pages were taken over by Brian Napper, with a new top page giving considerable detail on the Celebration arrangements, based on a newsletter produced by Professor Hilary Kahn, who is the coordinator of the University celebrations and is taking a major role in the organisation. She runs the 1998 Conference Office.

The original Mark1 pages included some pages translated into Japanese. Unfortunately we no longer have the expertise to maintain this.

October 1997

The Mark1 and Virtual Museum pages were transferred to a new site,, and work started to tidy up the pages (e.g. removing typographical errors, adding links, making small editorial and factual changes); this is an ongoing process, and will in general not be logged.

November 1997

The following substantive additions have been made to the Celebrations page :

10th December 1997

The reference on the Celebrations page to the special Hallé birthday concert on the evening of Wednesday 17th has been moved from the section on The Birthday Party to Complementary Events. (See also the 3rd paragraph of Computing Conferences.)

Provisional details of the Hallé concert have been provided.

12th December 1997

In the reference to the first program written for the "Baby" (in the page on the Baby in the Mark1 pages) the link from the picture of the program has been expanded to give a description of the program, and a link added in the annotation to a fuller description of the Baby order code.

Details of the Hallé concert have been confirmed.

18th December 1997

Biographies of the soloist Philip Dukes and conductor Owain Arwel Hughes have been added to the Hallé concert program.

A title has been given for the Psychology conference : Computers, Tools and Models for Studying the Mind.

8th January 1998

The following changes have been made to the Celebrations page :

The references to the "Official Birthday Party" have been changed to the "Launch Event" to reflect the official name of the event, and the description of this Launch Event has been changed to give the latest position. Note that the time of 2.15 for the event is not certain and has been removed. It is more likely to start nearer 3.15. The expected length is about 90 minutes.

A link has been added in The Rebuilding of the "Baby" to the SSEM Rebuild Project pages of the Computer Conservation Society where you can find information on the Project.

A new event has been added to the Complementary Events section : There will be an amateur radio station on the air between 3rd June and 1st July 1998, callsign GB50MKI.

12th January 1998

Work is in progress to integrate the Mark 1 pages produced by Joanne Allison with the pages in the Virtual Museum (and revise them). The two pages on F.C.Williams have been combined, with additional material, and the original V.M. Williams URL has been removed from the tree. The V.M. pages on the Williams Tube and its display have been revised.

22nd January 1998

The unification and revision of the page on the Baby from the Celebration Mark 1 pages and the page on the Mark 1 from the Virtual Museum pages has nearly been completed. I am releasing it now (with fingers crossed) as it might be another couple of weeks before I can complete it and triple check it. (It is the Ferranti Mark 1 page that is a quick cobble! I want to revise it a bit and in particular add a bit more on programming in 1952!)

The story has been split into 4 pages : Introduction, The Baby, Manchester Mark 1, Ferranti Mark 1. There have been some consequential corrections/improvements to the display pictures of the Williams-Kilburn tube and the annotation to the First Program. The replaced files remain, with their original names, but they have been linked out of the top level tree of files; links within them get back into the current tree.

19th February 1998

With apologies, I have done a significant revision of the Mark 1 pages based on some more of my own research to try and make sure the story is as accurate as possible. This has resulted in more material, some of it in the main stream of the story. I hope this makes a better contribution to telling the true story without too much unwelcome extra detail.

Revised pages are : Mark 1 Story Intro, The Baby, Manchester Mark 1, Ferranti Mark 1, Display Tube, 1st Program.

Anyone who has been using these pages as a source for material on the Baby and Mark 1 is advised to read through them again. There is quite a bit of detail that has been amended. For the more casual reader the most important thing is that I have tried to dispel two common myths : that you could read the information in a Williams-Kilburn Tube from the phosphor glowing on its face (see Display for a Williams-Kilburn Tube), and that the original program run lasted 52 minutes.

Another thing I have done is to up the profile of the Magnetic Drum on the Manchester/Ferranti Mark 1. On the Ferranti Mark 1 the drum could hold up to 512 pages of 32 * 40-bit numbers, i.e. over 16000 integers, or 82 Kbytes. Any page on drum could be transferred to any page in RAM within one revolution, i.e. about 25 milliseconds. On the Manchester Mark 1 the capacity of its drum store gradually increased between April 1949, when the original drum only had a few tracks working, and the end of 1949, when it had a maximum of around 128 pages. All the mechanical and electronic engineering required to manufacture the first Manchester Mark 1 drum was devised and executed in the University. Without having researched the area thoroughly, I suspect that this achievement was not matched elsewhere at the time, and it gave a flying start to today's hard disc.

Compared with the January 22nd revision, I have now got the Ferranti Mark 1 page done, with only a section on Programming on the Mark 1 to be completed.

I will shortly complete a revision of the biography pages for F.C. Williams and Tom Kilburn and on the Williams-Kilburn Tube (you can tell unrevised pages by their outdated style at the top of the page!).

There is little change to the Celebrations Page, except that we can report that the SSEM rebuild is working sufficiently well to be transferred to its final home, to be reassembled and completed by June. Also any Manchester graduates or other personnel connected with the early days, should reread the Reunions section.

11th March 1998

The major revision of the biography of Tom Kilburn has now happened. I have asked Tom (and Dai) questions and discussed things with him and have read some notes/transcripts of unpublished material he has written/spoken, but this biography has not been checked by him (or Dai).

As a result of the extra information gained in writing the revised biography, there have been some minor alterations/additions to the rest of the text, particularly for the Williams Tube and the First Program. Note that the suggestion that the Williams Tube should more correctly be called the Williams-Kilburn Tube is my own opinion as I learn more of the detail of what went on in 1947, but I am not the only one who has formed this opinion.

17th March 1998

The Celebrations page now includes references to the following new pages :

Celebrations Section-->New Page
The Launch Event Provisional Programme Details
Honorary Degree ceremony
Complementary Events Open Day at the University
     Computer Building (Sat. 20th)
Golden Anniversary Conference Provisional Programme Details
BSHS New Directions in the
     History of British Computing
Conference Details

27th March 1998

The revised biography of F.C. Williams is now complete. Note also the story I have acquired from Tommy Thomas on how Freddie Williams improvised when collecting components for the original magnetic drum for the Manchester Mark 1!

3rd April 1998

I have added a page Contemporary Computers (1946-51) to put the Mark 1 Story in a world context. I (don't really) apologise for the bias in quantity of words on the U.K. story relative to the U.S.A. story, but I think this is a necessary counterweight to a common American view that the U.K. effort was minimal. I acknowledge the useful input of Chronology of Digital Computing Machines (up to 1952), which is so accurate on the U.K. story that I presume it is accurate on the U.S. side! (I was not happy with "The Chronology of Computer History" from the "Historical Computer Society" that perpetrates a howler worthy of any collection of exam howlers: "1941: Colossus computer is designed by Alan M. Turing and built by M.H.A. Neuman at the University of Manchester, England".)

23rd April 1998

A full description of the Open Day on Saturday June 20th is now given. All are welcome.

I am still making small (but sometimes significant) corrections to all the Mark 1 material as I continue to do my own researches to get the story as accurate as possible. So anyone using the material as source is advised to double-check the pages before completing their work. I am trying to get a revised story out on Turing and Max Newman, but it is being delayed by pressure of other related work.

3rd May 1998

A seminar has been added to the list of conferences, History and the Future: Computers and Conservation, Wednesday 17th, 11.00 - 13.00.

14th May 1998

The page on Programming the Mark 1 is eventually out. (I am also aware of the technical problems on the links from the pictures on the top pages of the Virtual Museum -- please use the textual links underneath till I sort it out!)

29th May 1998

The revised page on Alan Turing has eventually arrived, which contains a biography of him, with acknowledgement to the ultimate source, Andrew Hodges, with his Alan Turing Website (though he may not agree with all my interpretation!). And there is a new piece on the contribution of the Maths Department at Manchester (i.e. Newman and Turing) to the Mark 1 project (with the Turing section replicating the appropriate section of his biography).

There are some consequential small changes to the page on Contemporary Computers.

(I have not got as far as I would have liked with my researches, but I want to get these pages out, as they complete the key material I wanted to produce (or revise) before the Celebrations. In particular I am still trying to find out (in limited time) whether Newman, Good and Rees produced any material on the subject of possible applications and techniques for computers in Maths and the sciences which was (or could have been) useful input to the design work of the Williams/Kilburn team and the production of the initial software. Failing this I am still of the opinion that the contribution of Newman was relatively small. Even when the Mark 1 project took advantage of his funding (September 1948) I find it difficult to believe, given the strong government backing (to Ferranti) made within a few months of the first program run, that the money would not have been obtainable from elsewhere.)

16th June 1998

The official Programme of the "Launch Event" is now given.

3rd July 1998

The description of the Golden Anniversary Conference has been turned into the past tense, and the biographical details from the actual programme (of the first day) added on another page. These short biographies are used to provide an extra entry Other People on the top page for the People column of the Mark 1 Story. This is long overdue, and hopefully some more entries will be added in time. (Individual entries will shortly be linked in to the main narrative as appropriate.)

9th July 1998

The Celebration pages have now been revised to reflect the fact that the main University celebrations are now in the past.

A new page has been added describing the ceremonies on the true anniversary, June 21st 1998, the official hand-over of the Rebuilt Baby to the Museum of Science and Industry in Manchester, and the prizegiving ceremony for the Baby programming Competition.

21st August 1998

There has been a general revision of all the pages in the light of my best current understanding of the history. These changes are in general very small, but again I advise anyone using these pages as source for material they are creating to double-check the most relevant pages. Perhaps the most substantive addition is a description of how refreshing of the main CRT store was interleaved and overlapped with the central operation of the computer.

A substantial set of documents has now been included in the Mark 1 Literature section, although two papers are still to be converted (from the different format on the CD-ROM). It is hoped to add one more paper soon.

9th November 1998

I have now completed a careful check of the Ferranti Mark 1 Programmers' Handbook, Chapter 1, from the 2nd edition, which is a major revision by Tony Brooker et al. of the first manual, written by Alan Turing. I hope there are now no errors in transcription in the document, but I have made some changes to correct errors in the original. I have looked carefully at all the examples given, and added (links to) notes where I think the original was wrong or obscure. I have also created a page giving the Table of Contents for the whole Handbook (with the notes at the end), and I have created a page giving the Ferranti Mark 1 Instruction Codes, including an "Abbreviated Instruction Code" copied from the Appendix, which is in numerical order of code, plus a Summary Instruction Code, which is in a more useful logical order. Each instruction mnemonic links back to the appropriate point in the Handbook.

20th November 1998

The two papers The New Universal Computing Machine at the University of Manchester and Universal High-Speed Digital Computers: A Small-Scale Experimental Machine are now in the library.

25th November 1998

An organised Picture Gallery now exists, including a few 1998 pictures.

2nd December 1998

I have modified the piece "Contemporary Computers (1946-51)" to be kinder about Newman's contribution to the Manchester computers, and have made a number of minor revisions to the page as well.

I have tidied up the few bits of the original Virtual Museum which I have not revised, i.e. the material on the University of Manchester computers after the Mark 1 (in particular removing the MAP operation that has not been working for some months).

18th December 1998

I have at last put in a description of the Atlas Interrupt mechanism, illustrated with paper tape input, as an example of the sophistication of the MUSE/Atlas design (1956 - 1962) in the section on Atlas in the biography of Tom Kilburn.

16th February 1999

A page has now been added summarising the contribution of MU5 to the ICL VME2900 series. Although it was not acknowledged in ICL's launch of the 2900 series in 1974, the design of MU5 was a major influence in the architecture of the 2900 series. (This page is now linked in to Tom's biography and the Home Page, where it cites Tom's biography as a useful history of the set of computers designed in the department up to 1974.)

This page draws on the annotated slides (in pdf format) for Brian Procter's talk at the Golden Anniversary Conference. These are now included on the pages. This is part of a slow process that is proceeding for enhancing the Computer50 pages with versions of the talks given on the first day of the conference, and adding some more photographs.

16th March 1999

Considerable progress has now been made on extending the Picture Gallery to record the events of June 1998.

6th April 1999

I have at last decided (and been encouraged!) to adopt the policy of referring by default to the "Williams Tube" as the "Williams-Kilburn Tube" (see reasons). I have been dithering about this for over a year, torn between preferring accuracy and not wanting to rewrite history! This follows the policy of Professor Simon Lavington last year in the revised version of his book "A History of Manchester Computers". There are accordingly consequential changes throughout the pages.

5th May 1999

I have now read Andrew Hodges' excellent and comprehensive biography of Turing, and parts of other books and pamphlets on Bletchley Park, and as a result I have been able to make some corrections and additions, mostly in the area of the Turing and Newman histories, and the review of Contemporary Computers (1946-51).

20th August 1999

I have included a significant section on the 1946 Moore School lectures. This is now a top-level item in the Mark 1 Story, as well as being linked in to the review of Contemporary Computers (1946-51). This new section derives from having a day free in Philadelpia in May, and feeling I couldn't pass up the chance to visit the School, and see the Mauchly Papers in the Van Pelt Library. One thing led to another (see Acknowledgements) and I have produced a list of the 48 lectures and lecturers, an introduction and background to the lectures, and a 12,000 word digest of some of the later lectures.

These lectures, plus two or three other reports, give a comprehensive State of the Art picture of the development towards the electronic stored-program computer at the precise time (July/August 1946) that Freddie Williams decided to enter the world of computers.

31st August 1999

I have now acquired a book published in 1985, which reprints the Moore School lectures, with much useful additional material. This has enabled me to correct and improve the pages on the 1946 Moore School Course. I may or may not extend the digest to cover earlier lectures.

I have also (both before and after the August 20th extension) made minor alterations to various references in the Mark 1 pages to the general contemporary world scene w.r.t. progress on storage devices (e.g. most obviously in the review of the contemporary scene). This is mainly due to a better understanding of the history of the Selectron Tube. In the process I have now separated the previous single note "The Mercury Acoustic Delay Line or Why Tom Kilburn didn't like the NPL Computer Design" into two notes -- long overdue.

12th February 2000

I am delighted that a transcription of Turing's First Edition of the Programmers' Handbook for the Manchester Electronic Computer Mark II (i.e. the Ferranti Mark 1) has just been carried out by Robert S. Thau at MIT. I have incorporated it in the list of the Mark 1 Literature, although of course the link in the heading is to Robert Thau's website (as is the above link).

[Note (July 2005) : I have been given permission by Robert Tau to include copies of his transcription on this website, in both PDF and HTML. So the links (now to this website's copy) are working again!]

This site only has the first chapter of the second edition, which starts with Turing's first few sections, and then diverges to give just a full description of the machine. An auxiliary page gives the full list of contents of the Second Edition, and I have added to this page the list of contents of the First Edition, with links for the top level headings into Robert Thau's transcription.

This should make it easier to compare the general content of the two manuals.

31st May 2000

There is now also a facsimile of Turing's First Edition of the Programmers' Handbook for the Manchester Electronic Computer Mark II (i.e. the Ferranti Mark 1), on the The Turing Archive for the History of Computing website maintained at the University of Canterbury, New Zealand.

I have therefore annotated the list of contents of the First Edition (see previous log entry) with page numbers in the original manual for all the headings and subheadings. Each number is a link to the corresponding page in the facsimile. I have also transcribed the Index from the back of the manual, setting each page number as a link to the corresponding page in the facsimile.

15th October 2000

I have acquired a few more photographs for the Picture Gallery (thankyou Khalil), in particular a coherent set of the Degree Ceremony which took place at the end of the Launch Event. This set has been added as a subset of the Launch Event. I have also altered the navigation of the pictures so that you can choose to see the pictures individually as well as in sets of around 8 or so (except for the Degree Ceremony). Unfortunately the negatives of the missing pictures (which were never printed in full) are still mislaid.

I have also tidied up what remains of the original Virtual Museum (by Kulwinder Gill), so that it is clear what the scope of the Museum is (which is very limited, but still of some use). It gives a brief history and some pictures for each of the post-51 Manchester University machines built under Tom Kilburn, with the material on the Mark 1 machines having been integrated into the main computer50 website.

17th January 2001

Sadly Tom Kilburn died today. He had an unexpected reaction to a minor procedure in November, and after the resulting emergency major surgery was in intensive care for five weeks. But after a second operation he made a remarkable recovery and by the end of last week was looking forward to leaving hospital in a couple of weeks. Unfortunately he had unexpected complications over the weekend and this time the medical staff were unable to save him.

As the existing piece on these pages on Tom is so long, I am writing a short piece summarising his achievements. I also plan shortly to write a longer piece placing his achievements in the context of the contemporary computing scene over his working life.

20th May 2001

The page containing the announcement of the Memorial Service on May 1st 2001 has been converted to the past tense, and the Order of Service added. A page has been added which gives the text of the tributes and other content from the Memorial Service, with some annotation.

7th October 2001

I have opened up a new section, "Reminiscences", to hold formal and informal documents which provide memories of the Mark 1 era, and the period immediately following it. This is linked from the top page underneath "Mark 1 Literature" under the list of major headings given for The Mark 1 Story.

I would welcome any further contributions.

3rd November 2003

I am still here. I have quite a bit of material stacked up, but at last I have actually got some of it onto the pages!

I have added to the Mark 1 Literature a transcription of Tom Kilburn's 1947 Report to TRE. This was a key document towards the Williams-Kilburn Tube being taken up world-wide as the early alternative storage mechanism to the Mercury Acoustic Delay Line.

The report has been retyped, and checked very carefully both with the original and the 1949 Paper published by the I.E.E., which was closely based on it. I have provided a Covering Description, which gives some background to the Report, and a description of the associated material (diagrams etc.) and how it is organised. Also given is a summary of the editing that has been done for the transcription relative to the original, and a summary of the differences between the Report and the 1949 Paper.

16th November 2003

To celebrate the 50th anniversary of the next innovative machine to work in Tom Kilburn's Computer Group, the "Transistor Computer", a note is added by its builder, Dick Grimsdale.

I hope to mark this anniversary, and ones for later machines, with additional material on the machine. I have revised the 1996 description by Kulwinder Gill in the "Virtual Museum".

24th November 2003

I have now included some information on the Ferranti Mark 1*. This was the revised version of the Ferranti Mark 1 which had essentially the same architecture, but a much reduced but improved order code, which eliminated most of the idiosyncrasies and irritations of the programming conventions and order code of the Mark 1.

A summary is given of the changes from the Mark 1 and the new order code.

30th March 2005

These pages have been revised to take account of the merger in 2004 between the Victoria University of Manchester and UMIST. This has resulted in changes in names, URLs, Email addresses, etc. -- most obviously that the University is now The University of Manchester (with a capital T) and the Department the School of Computer Science. And the new University is now at "" not "" (though it will take time for all material to migrate).

As part of the process, I have taken the opportunity to review all my links. Obviously over the years some have died and some have changed (and some within the University are still to change?). In general I have still shown the dead links, but as underlined black text.

As the old "prog98" pages describing the Baby programming Competition are no longer maintained, I have now incorporated all the previously visible content into the Computer 50 pages, to avoid the risk of the prog98 pages disappearing in their original form. In doing so I have simplified the presentation (but not the content), and made it consistent with the (lack of) style of the rest of the Computer 50 pages.

Hopefully, now that I am back in the swing of things, I will soon be able to start adding the backlog of material I have planned.

This page is maintained by Brian Napper.

Copyright The University of Manchester 1998, 1999, 2000, 2001, 2003, 2005