Talk:Manchester Mark 1

Question
April 1954 or 1949?

The article said "The first version of the machine was running in April 1954". The book "Early Britis Computers", page 37 says that it was used to investigate Mersenne primes in April 1949. It ran overnight in June 1949, and that it was completed in October 1949.--Bubba73 16:22, 4 Jun 2005 (UTC)

Mark I coincidence
Is it by pure coincidence that this machine shares a similar name to Harvard Mark I? --Abdull 10:17, 11 March 2007 (UTC)


 * Yes, unrelated. However, the Baby Mark 1, Ferranti Mark 1 and intermediary version of the Manchester Mark 1 where all known as the "Mark 1" despite being different evolutions of the same machines. This link has something to say on the matter. --BlueNovember 00:01, 12 November 2007 (UTC)

Size of a page
I'm confused by this text:


 * ''The Mark I included two tubes, each storing 64 rows ("double density") of 40 points, for a total of 128 words. 64 words was considered to be a single "page", so the system stored 4 pages. Freddie Williams deliberately sized the drum to store two "pages" of Williams tube data – that is, 2x32x40 = 2,560 bits – per track, and 32 tracks in total.

The word size is 40 bits. Each tube stores 64 words. There are two tubes. 64×2 = 128. This makes sense. Then it says there were four pages. How exactly does 64×4 = 128? Did I miss something? Apparently two pages of data is 2×32 words... so presumably the article should say '32 words was considered to be a single "page"'? --StuartBrady (Talk) 19:08, 11 September 2007 (UTC)

Re-name the article?
Can the article name be corrected from "Mark I" to "Mark 1"? TedColes (talk) 18:19, 1 December 2008 (UTC)


 * I'd certainly be in favour of that. There's a redirect from Manchester Mark 1 to here though, so I'm not sure whether that means the move's got to be done by an administrator? --Malleus Fatuorum 18:23, 1 December 2008 (UTC)


 * I'm in favour of changing it as it's not consistent with the text but it will need to be done by an admin as the name's already in use. Richerman (talk) 11:48, 2 December 2008 (UTC)

Met Office thing
http://www.computer50.org/mark1/gac1.html states that it was the Ferranti mark one that was used by the met office, not the manchester mark one, —Preceding unsigned comment added by Steroberts89 (talk • contribs) 00:35, 16 January 2009 (UTC)


 * Fixed ✅ Richerman (talk) 12:35, 16 January 2009 (UTC)

Berners-Lee/Mark 1 confusion
I've removed the claim that Tim Berners-Lee's Dad, Conway Berners-Lee, worked on the Manchester Mark 1. He actually worked on the Ferranti Mark 1. --Malleus Fatuorum 20:11, 22 January 2009 (UTC)

Well done
Superb - well written and comprehensive. I added a few links, such as word and page

Any point in putting the translation table in so people can see how the info changes through the process? eg

I know that looks ugly but was just as an example !--Chaosdruid (talk) 18:28, 25 January 2009 (UTC)
 * PS - just added link to Mark 1 in the Mersenne prime page


 * I'm not sure. The article does already say that the Mark 1 reversed the conventional ordering of significant digits ... I was tempted at one point to include a table of the complete mapping of teleprinter codes to binary values, but thought better of it. It's very difficult writing encyclopedia articles, rather than articles about some topic or other, and I've certainly struggled with that in the past. My take on it is that we're trying to give a comprehensive summary, not a comprehensive account, if that makes any sense. --Malleus Fatuorum 18:49, 25 January 2009 (UTC)


 * Yup makes perfect sense - it is difficult to know where to draw the line between essay and article for me lol--Chaosdruid (talk) 22:15, 25 January 2009 (UTC)

Problem
This article repeatedly refers to the Manchester Mark 1 as "one of the earliest stored-program computers" and links the stored-program to Von Neumann architecture. These terms are not synonymous.

A Von Neumann architecture has a dedicated memory for storing instructions which is separate from the memory used to store the program data. Von Neumann architectures are frequently contrasted with Harvard architectures, which use the same memory to store both programs and instructions. However, *both* Von Neumann and Harvard architectures store the program somewhere.

It would be more accurate to contrast a stored program computer (be it a Harvard or Von Neuman design) with a single purpose computer with a hardwired program (ala, the Atanasoff–Berry Computer), or perhaps with a reprogrammable computer that uses a physical medium (like punch tape) for program storage rather than electronic.

I've turned Stored-program computer (which was previously a bad redirect to Von Neumann architecture) into a legit article. I'm going to link the terms from here to there. Raul654 (talk) 06:55, 10 November 2010 (UTC)

How many pages per Williams tube?
According to Nature, Vol 164, Oct 22,1949, p684. Dr. T. KILBURN http://www.digital60.org/birth/manchestercomputers/mark1/documents/natureart.html

"A single storage tube has a capacity of 2,560 digits, arranged in two rasters of television type, where each raster has 32 lines, and each line of a raster holds 40 digits."

- that is, each Williams tube held two pages, not one.

86.141.196.130 (talk) 23:37, 5 January 2014 (UTC)

Exact description of Final Spec store size
It seems to me that:

"The capacity was increased to 4 Williams tube and 128 magnetic drum pages in the Final Specification version."

is incorrect, since that phrasing indicates that only four pages of main store were implemented when in fact four tubes were used to provide eight pages.

Thus, a formulation such as:

"The capacity was increased in the Final Specification version to eight pages of main store on four Williams tubes and 128 magnetic drum pages of backing store."

seems to be called for: correctly describing the amount of store provided in a fairly concise and very clear manner.

86.141.196.130 (talk) 00:03, 6 January 2014 (UTC)


 * Obviously I don't agree, as now we've established that the Mk I used double-density Williams tubes anyone can easily work out for themselves how many pages of main store that represents. But I'm fed up arguing the toss with you. Eric   Corbett  00:38, 6 January 2014 (UTC)

The way I look at it, the reader shouldn't have to work things out like that; indeed, requiring the reader to work out things like that is sure to result in many readers misunderstanding what's written.

The text should be written clearly so the reader can understand it without trouble. If it's practical to help the reader avoid mistakes in comprehension, then the text should do so.

(one must be careful to avoid wind-baggery when trying to do this - I think I've managed that much at least)

One problem is that the term "double-density" tubes doesn't help - what's a "single-density" tube? Implicitly, one of half the capacity of a double-density tube. But that's all we get from the phrase - and then only if you make the link between "density" and "capacity" (which most would, I'd hope). How does that help anyone? I don't get it. Double-density might be a correct term, but it's not an aid to reader understanding of the article in my view.

Stating plainly that the tubes in question each held "two arrays of 32 x 40-bit words – known as pages": that's helpful.

Back to your suggested phrasing:

"The capacity was increased to four Williams tubes and 128 magnetic drum pages in the Final Specification version"

Is indeed no longer an incorrect statement - "4 Williams tubes" rather than "4 Williams tube [...] pages".

However, I think a reader could easily slip up and misunderstand what was meant, so it's a better idea to explain things clearly. Since it's easy enough to do so without being long-winded about it, why not leave my phrasing in place?

My point is not that your phrasing is wrong, just that it's liable to lead to misunderstanding which could very easily be avoided.

86.141.196.130 (talk) 01:01, 6 January 2014 (UTC)

Main and backing store description.
I feel it is helpful to describe the size of the working stores not only in terms that describe the machine architecture - that is, in terms of pages - but also in terms of words. My reasoning is that it's easier for the reader to comprehend both the machine architecture and the size of store provided if store size is described both as number of pages and number of words.

It is also (obviously to my mind) helpful to explain what is meant by "backing store", since the concept is not obvious.

Finally, the term "double density" when applied to Williams tubes is not helpful to the reader for the following reasons:

1: "Single density" is not defined.

2: For the term to carry meaning, the reader must understand that the "density" described is an areal density, and that area has been conserved from "single" to "double" density storage devices.

For those reasons, it makes sense to remove the reference to "double density" since it does nothing to aid reader comprehension.

I suggest that my edits be left to stand unless there are clear reasons to contradict any of my reasoning. 86.141.217.115 (talk) 01:46, 28 January 2014 (UTC)

I would like to remind editors of this page of Wikipedia_talk:Civility: Wikipedia operates on the following fundamental principles, known as the five pillars:

I wish to discuss this matter courteously in order to avoid an edit war. I assume good faith on the part of other editors of this article. 86.141.217.115 (talk) 02:07, 28 January 2014 (UTC)

What's wrong with this description of storage? (attempting to resolve disagreement)
The SSEM's 32-bit word length was increased to 40 bits. Each word could hold either one 40-bit number or two 20-bit program instructions. The main store initially consisted of two Williams tubes, each holding two arrays of 32 x 40-bit words – known as pages – with a backing store provided by a magnetic drum capable of storing an additional 32 pages (128 words main store; 1024 words backing store). The capacity was increased in the Final Specification version to eight pages of main store on four Williams tubes and 128 magnetic drum pages of backing store (256 words main store; 4094 words backing store).

The magnetic drum memory on the Mark 1 was not file store, but was used as part of the computer's working memory rather like a crude version of virtual memory, with transfers between slow magnetic drum and fast Williams tube main store being intiated by programmed instructions. The 12 in diameter drum, initially known as a magnetic wheel, contained a series of parallel magnetic tracks around its surface, each with its own read/write head. Each track held 2,560 bits, corresponding to 2 pages (2 x 32 x 40 bits). One revolution of the drum took 30 milliseconds, during which time both pages could be transferred to the CRT main memory, although the actual data transfer time depended on the latency, the time it took for a page to arrive under the read/write head. Writing pages to the drum took about twice as long as reading. The drum's rotational speed was synchronised to the main central processor clock, which allowed for additional drums to be added. Data was recorded onto the drum using a phase modulation technique still known today as Manchester coding.

86.141.217.115 (talk) 03:01, 28 January 2014 (UTC)


 * It is disappointing to see this sort of to-ing and fro-ing between two editors. It is not a dispute of fact or interpretation, only one of style of expression. Clarity is of great importance and we should always strive for it. I admit to a slight prejudice against un-registered, anonymous editors, as in my experience, their edits are often un-helpful or vandalism. However, my preference on this occasion is for the version by 86.141.217.115 over that by Eric Corbett, with the following exceptions. (1) I marginally prefer "backed up by a magnetic drum" to "with a backing store provided by a magnetic drum", as it gradually introduces the reader to the concept in the phrase "backing store" that is used later, and which may be new to them. (2) I am unsure as to whether "rather like a crude version of virtual memory" is helpful for the less well-informed reader and it could well be deleted. I am not going to change the article just yet and would encourage others to express their views. --TedColes (talk) 11:47, 28 January 2014 (UTC)


 * Thank you for your well considered feedback.


 * The problem with the phrase "backed up by a magnetic drum" to my mind is that it makes the mag drum sound like a modern "file backup store", which it wasn't. Admittedly, the drum did get used to back up (in the modern sense) intermediate results against errors occurring during a run (the machinery was prone to intermittent faults - i.e., in modern terms, the thing was flaky as hell), but "file store" in the modern sense was on punched paper tape.


 * On the other hand, "backing store" isn't as usefully self-explanatory as maybe I'd thought. This needs some more thought.


 * I agree with your point regarding the analogy to virtual memory. Still, I think something needs to be done to explain how this part of the machinery worked rather than leaving it up to the reader to work it out from implication.  On the other hand, how exactly was the magnetic backing store used?  The more I read on the subject, the more it seems that the users of the Manchester Mark 1 (as opposed to the Ferranti Mark 1) used it in any way they thought useful.  After the Manchester Mark 1 had been scrapped and Autocode was developed, the way in which the backing store got used was (for users of Autocode at least) seemingly settled by the software.


 * I don't know what to do about this and shall think about it.


 * Regardless of all that, I don't see any possible argument against expressing the store size in words as well as pages. Any comments from anyone?


 * 86.141.217.115 (talk) 14:25, 28 January 2014 (UTC)


 * I have read through the two versions of the article. I am broadly in favour of Eric's version, but I prefer 86's decision to not include the phrase "double-density" referring to the Williams tubes, which has not been defined or linked by that point in the article. CRT should not have a link, as cathode ray tube (CRT) is defined earlier in the article. The problem with technical details is you need a balance between being a good definition of the computer's features, but one that a typical layman reader would understand. A non-expert would still understand the concept of bytes and storage through waiting for a file to copy on Windows, for example. Ritchie333  (talk)  (cont)   07:56, 29 January 2014 (UTC)


 * As someone who used to teach people how to use Windows computers, I'm sorry to report that most people do not pick up the concepts of bytes and storage in the way you think they should (FWIW, I've found every Windows UI since Windows 3.11 to be progressively more confusing). These are things which need to be explained carefully to a lot of people.  Lots of people need every concept relating to a computer filing system explained one step at a time to understand it, which isn't to say that they're stupid or slow on the uptake, just that they've not had a chance to learn and need information.


 * However, you can't provide that sort of explanation in every computing-related article: some sort of judgement needs to be applied on what you can expect the reader to know. I work on the basis that they've got some understanding of very basic concepts, i.e., what a "bit" is and the idea that you keep the things in what gets called "storage" or "memory" or what have you.  But it's all very subjective and hand-waving, is this sort of judgement.


 * What do you think of the addition of storage size in words? E.g., "The capacity was increased in the Final Specification version to eight pages of main store on four Williams tubes and 128 magnetic drum pages of backing store (256 words main store; 4094 words backing store)"


 * Michael F 1967 (talk) 05:34, 30 January 2014 (UTC)


 * Just to clarify, I simply mean that people have heard of the word "byte" and know it's something to do with computers. In the case of the Mark I, I would stick with "word" as "byte" is widely assumed to be 8 bits long - there's no point simplifying things to the point of being factually wrong. The essays on writing better articles and basic copyediting have further information. Ritchie333  (talk)  (cont)   08:42, 30 January 2014 (UTC)


 * Thanks for the pointers, although I'm not sure which parts of those two very helpful articles you think are particularly applicable to this job. My recent edits were focussed on the ideas discussed in BETTER.


 * On the subject of the term "byte" with respect to the Manchester Mark 1:


 * Given that "Historically, the byte was the number of bits used to encode a single character of text in a computer", it could reasonably be said that the Manchester Mark 1 used eight five bit bytes to the [40 bit] word - which is out of line with current general usage. The term "byte" was coined about six years after the Mark 1 had been scrapped.  For those two reasons, I'd suggest that the word "byte" has no role in describing the Manchester Mark 1.


 * Michael F 1967 (talk) 23:33, 4 February 2014 (UTC)

Suggestions please on how to resolve problems with User:Eric_Corbett
I've been trying to resolve the difference of opinion I have with User:Eric_Corbett using discussion.

The nearest thing to a substantial response I've managed to get from him is:

User_talk:Eric_Corbett

"I haven't read your comments anywhere, as I have absolutely no interest in anything you might have to say. Eric Corbett 14:46, 28 January 2014 (UTC)"

Clearly, if User:Eric_Corbett won't engage in discussion with me, there's no way of resolving any differences of opinion we might have, which is just as obviously bad for any Wikipedia pages where we might have a conflict of ideas.

I'd appreciate any suggestions on what I should do next.

86.141.217.115 (talk) 16:11, 28 January 2014 (UTC)


 * What to do next? Stop trying, focus on the forward-looking section above this one. If you have suggestions to make, and your suggestions gain supports as improvements over the current Eric-sanctioned version (i.e. more than just swapping minor words) then there is some chance that a cadre/consensus/clique/coven of other editors might support them, despite Eric's views.
 * Alternatively just walk away and stay well clear of Eric. New editors are not welcome.
 * As to the EW closure last night, then "stale" isn't the phrase I'd have used, but I can see the virtue in Callanecc's early close of this. You are an unregistered account and a new editor, therefore you will be treated here as an ignorant vandal. An EW action would likely have meant an indef block for you (undeserved, but common) and another trip to the WP:ANI funfair for Eric. Neither of those would have achieved the slightest. Andy Dingley (talk) 16:15, 28 January 2014 (UTC)


 * Thank you for your comments. (I've had to reboot my router, hence the IP address change).  I am indeed focussed on the article, and looking at the feedback I've received above.  I am however concerned that Eric will just revert any changes I make, regardless - action which seems out of line with the guidelines I've read on how to work in Wikipedia.


 * I'm not sure why I should be treated as an ignorant vandal, given the remarks on my edit provided by User:TedColes. Could you explain further?


 * Could you explain your remark "New editors are not welcome"?


 * Thank you once again.


 * 86.145.109.150 (talk) 16:42, 28 January 2014 (UTC)


 * Replying to the comment on my talk page here.
 * Had I come across the AN3 report sooner than the 9 hours I did there would have been a short block (not indef as Andy suggests) for both of you for violating 3RR. However blocking someone to stop edit warring which had already stopped 9 hours before doesn't achieve anything preventative.
 * In terms of my comment which said "discuss rather than revert" that does apply to both of you as you both broke 3RR. What you should have done is, once it had been reverted come to the talk page and ask for other opinions (which you have now) rather than edit war.
 * Given Eric hasn't commented in the section above any agreement between users is enough to warrant making the change, if Eric reverts again then he's reverting against a consensus version without commenting and we/I can use the protect or block buttons. Callanecc (talk • contribs • logs) 00:27, 29 January 2014 (UTC)


 * Thank you for your kind explanations.


 * This next bit might sound like I'm trying to excuse past bad behaviour on my part, but that is not my intention. I'd just like to point out that despite my improper "edit warring" behaviour (which I will not repeat now I've learnt better), I did in fact come to the talk page and ask for other opinions after the second reversion of my edits.  I also repeatedly urged the other editor involved to engage with me on the talk page.  That's why I didn't understand your comment that we should both remember to discuss rather than revert: I might well have been constantly reverting (which I learnt I shouldn't have done), but I had also initiated a discussion on the talk page.


 * Anyway, I've learnt better and I'll not forget how to deal with such situations in future.


 * Michael F 1967 (talk) 05:14, 30 January 2014 (UTC)


 * Just to throw my opinion into this, I don't think you've done anything wrong, Michael. New editors don't come to Wikipedia armed with a full and complete understanding of Wikipedia policies. Keep discussion focused on the Mark I (or whatever article you choose to work on) and avoid conversations about specific editors and their perceived merits, and you should have no problems. Ritchie333  (talk)  (cont)   08:42, 30 January 2014 (UTC)

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