Talk:EDSAC

Operational until when?
When was EDSAC dismantled and/or scrapped and/or simply retired? Please add this information if you have it. -- 92.229.248.14 (talk) 11:10, 25 April 2010 (UTC)

Was EDSAC first or second?
For the EDSAC 99 celebrations, Cambridge and Manchester discussed the correct form of words for describing EDSAC. I believe that the form of words on http://www.cl.cam.ac.uk/conference/EDSAC99/history.html (6 May 1949) were agreed with Manchester as being correct. That is, that EDSAC was "the first complete and fully operational regular electronic digital stored program computer". Neil Dodgson (talk) 16:08, 16 April 2012 (UTC)

Although Manchester's Mark I was available in April 1949, it was not fully operational until the Autumn of 1949 http://www.computer50.org/mark1/MM1.html Neil Dodgson (talk) 16:13, 16 April 2012 (UTC)

Good to know that Manchester agreed the wording now in the article. --TedColes (talk) 16:24, 16 April 2012 (UTC)

Using a report about Cambridge University compiled by Cambridge people is not confirmation that "Manchester agreed the wording in the article". Is there a reference to back up this claim?

The Manchester Mark 1 computer of 1949 (not to be confused with the SSEM "Baby" testbed machine of 1948, as seems to be the case in the EDSAC article) was in use for practical university research before EDSAC - that surely is evidence that Manchester had a really useful software programmable digital electronic computer working before Cambridge.



Kudos applies to both research groups - but...

Using the term "fully operation[al]" to describe the May 1949 EDSAC while claiming that the intermediate Manchester Mark 1 was not strikes me as misleading: the Manchester Mark 1 was indeed fully operational in April 1949, to the intermediate if not final specification. Evidence for that is given at the above url, which makes it clear the Mk 1 was being used for research at that time.

The Wikipedia EDSAC article explains that EDSAC was not complete in May 1949: it had no index registers which were added later (in 1953), and also had only half the intended memory when first commissioned.

EDSAC was neither more nor less "fully operational" in May 1949 than the intermediate Manchester Mark 1 of April 1949.

Neither machine was complete on those dates - which is what you'd expect with any of these early computers, all of which were works in progress throughout their operational lives.

However, both first became usefully operational on those dates - that surely is what counts?

I do not understand why the reference to the Manchester Mark 1's first use as a research machine (before EDSAC even ran its first program!) was removed.

The Manchester Mark 1 was a full scale machine (unlike the SSEM) and was available for computation in scientific research at Manchester University by April 1949. http://http://www.computer50.org.

That points to a page which states clearly:

"From this Small-Scale Experimental Machine a full-sized machine was designed and built, the Manchester Mark 1, which by April 1949 was generally available for computation in scientific research in the University"

Finally, if you really want to revert my edit, do at least make "operation" into "operational".

109.149.202.255 (talk) 00:18, 22 June 2012 (UTC)

Regarding the mistaken edit calling EDSAC the first to go into regular service: http://www.computer50.org/mark1/MM1.html states of the April 1949 version of the Manchester Mark 1: "This Intermediary Version was available for general use by other university departments and Ferranti. For example, it was used to perform useful work on Mersenne Primes during the summer of 1949. On the night of June 16/17th 1949 it was recorded as achieving a nine-hour error-free run."

EDSAC didn't start being used for research until May 1949, and therefore, based on the evidence I quote above, was the second to go into regular service.

Please do not change this without citing a sound reference contradicting the page I quote above.

5.81.52.117 (talk) 19:39, 5 January 2014 (UTC)

Manchester SSEM graphical computer game?
There is no reference provided to back up the claim that the Manchester SSEM ran the first graphical computer game. Unless this claim can be verified, surely it should be removed? My searching on-line indicates that the first such game ran on EDSAC: http://www.pong-story.com/1952.htm.

109.149.202.255 (talk) 20:59, 22 June 2012 (UTC)

Physical components
Wikipedia article claimed for EDSAC that "None of its components were experimental." but provided no references.

At: http://www.cl.cam.ac.uk/events/EDSAC99/reminiscences/#EDSAC%201%20construction

Herbert L Norris (Technician 1951-63) says:

"When working at the Engineering Laboratory (1940 - 1951), I produced a cylinder of brass about 3" diameter and 6" long, this was eventually to be covered by a ferrite material and to have a 'Head' travelling along it which was to read magnetic signals from this drum. I did not realise that I was in at the beginning of computers.

I was asked if I would like to join the Maths Lab in January 1951, and I was very pleased to do so. I never saw the drum working and I believe there was a problem with spraying the ferrite material on to give an even coat, and the development of the heads had not progressed enough to be run close to the surface."

- indicating that the mag drum store at least was indeed experimental hardware.

Donald Willis (Research Assistant 1948-50 & 1952-55) says that during 52-55:

"An experimental [tape] system was run on the EDSAC"

- likewise, some years after initial operation.

Therefore, I deleted this incorrect claim.

109.148.255.185 (talk) 22:20, 27 June 2013 (UTC)

External links modified
Hello fellow Wikipedians,

I have just added archive links to 1 one external link on Electronic Delay Storage Automatic Calculator. Please take a moment to review my edit. If necessary, add after the link to keep me from modifying it. Alternatively, you can add to keep me off the page altogether. I made the following changes:
 * Added archive https://web.archive.org/20141207025641/http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=560726&url=http%3A%2F%2Fieeexplore.ieee.org%2Fstamp%2Fstamp.jsp%3Ftp%3D%26arnumber%3D560726 to http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=560726&url=http%3A%2F%2Fieeexplore.ieee.org%2Fstamp%2Fstamp.jsp%3Ftp%3D%26arnumber%3D560726

When you have finished reviewing my changes, please set the checked parameter below to true to let others know.

Cheers. —cyberbot II  Talk to my owner :Online 02:37, 26 August 2015 (UTC)

Start of work on EDSAC
Unregistered User:Snowtrack and I have reverted each other's edits over this matter. User:Snowtrack has repeatedly changed the statement that "Work on EDSAC started at the end of 1946" to "Work on EDSAC started during 1947". This phrase is immediately followed by a citation to a source which states that "Work on the project started at the end of 1946, and the machine began to work in May 1949." If User:Snowtrack has better information from a reliable source, it should be cited. --TedColes (talk) 09:44, 16 October 2016 (UTC)

How much memory was in the delay line?
The booklet at Cambridge says that each delay line stored only 35 bits. http://www.cl.cam.ac.uk/events/EDSAC99/booklet.pdf — Preceding unsigned comment added by Simsong (talk • contribs) 16:57, 5 August 2017 (UTC)


 * That booklet describe short delay line, full response: Talk:Delay_line_memory --MarMi wiki (talk) 18:01, 26 December 2018 (UTC)

Requested move 12 November 2018

 * The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this section. 

The result of the move request was: moved (page mover nac) Flooded  with them hundreds  15:05, 19 November 2018 (UTC)

Electronic delay storage automatic calculator → EDSAC – Per WP:COMMONNAME, this should be at EDSAC and not the full expansion of the abbreviation, just like ENIAC, BINAC, EDVAC and all the other -ACs. 31.169.58.161 (talk) 14:02, 12 November 2018 (UTC)
 * Support. --Woofboy (talk) 20:07, 12 November 2018 (UTC)
 * Support per nom. Dicklyon (talk) 01:24, 13 November 2018 (UTC)


 * The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

Reference for future use
©Geni (talk) 23:04, 17 October 2019 (UTC)

Self modifying code
"The early programmers had to make use of techniques frowned upon today—especially altering the code" I don't frown upon it this is a bit judgmental. --Kitchen Knife (talk) 20:25, 30 April 2020 (UTC)

EDVAC's influence
The first paragraph states that the design of the EDSAC was inspired by that of the EDVAC. It seems to be more than just inspiration. Maurice Wilkes not only read the famous von Neumann's report. In August of 1946 he participated in a series of Moore School Lectures at the University of Pennsylvania about EDVAC design which obviously was an important influence. As a matter of fact, he produced the first sketch of the EDSAC design on his five-day return voyage by ship to England. Usage of delay mercury lines was proposed first by Eckart for the EDVAC. Even the name EDSAC is a reminder of this influence.Tsf (talk) 20:24, 4 July 2021 (UTC)