Talk:IBM 1401

message: Edward G. Nilges 3-25-2005 spinoza1111@yahoo.com: I have added information to this excellent article on 1401 software, notable installations, and in summary as to its human impact based on sources and personal experience. Let me know what you think, oh Collective.
:Keep right on going with anything you have. Please register a user name, so we can get to know you. -- RTC 00:23, 25 Mar 2005 (UTC)
thread_title: Introduction from RTC

message: From memory (of IBM UK Education Dept, 1961 - 64) the reason op codes 1 - 7 incl. did not need an address was that cards were always read into memory locations 1-80 and were punched from locations 101 - 180, and the line printer printed from locations 201 - 332 (printer line width was fixed at 132 characters).  This led to the most noisy instruction being the single op code  7   which read a card, punched a card and printed a line.
I also remember the difference between group marks and word marks, but not how they were coded. A word mark identified the op code.  A group mark might have been relevant only with tape I/O, but my memory is not clear on this. Was the character size increased by 1 bit to incorporate the word mark?
Van.snyder (talk) 01:07, 3 April 2011 (UTC)
thread_title:  IBM 1401: fixed I/O memory 

message: paragraph: "Major software on the 1401 included a simple assembler called the Symbolic Programming System (SPS) and a more advanced form of assembler, Autocoder. The only high-level language in common use was the RPG (Report Program Generator) language, a declarative language primarily for specifying accounting reports still in use on IBM's midrange AS/400."
Actually, a language called FARGO (Fourteen-o-one Automatic Report Generation Operation) was the predecessor of RPG. --YORD-the-unknown 15:50, 19 July 2006 (UTC)
thread_title:  Software 

message: The 1.4K, 2K, and 4K machines could not compile programs, and had to be supplied with programs compiled on a more expensive machine.  Assuming that "compile" as used here includes "assemble", I deleted this text and added some storage requiremnents to the later text about software. 69.106.254.246 17:42, 17 September 2006 (UTC)
replies: text: Good, I always felt that needed clarification. However I didn't have any details myself. -- RTC 20:16, 17 September 2006 (UTC)

text: Thanks for the interesting comments. What competitor had smaller cards? Remington Rand had more data (90 characters) on its cards, but they were the same size. I suspect the card size was appropriate in the electromechanical era, the rectangular holes produced nice clean pulses to relays when brushes made contact through them as the cards passed through the read station. Making all the mechanical equipment much smaller was probably not feasible in the 1920s and 30s. IBM introduced a much smaller format with the System/3, but that was late in the game and didn't last long. Also, I heard the CADET story about the IBM 1620, which used a lookup table for addition. The 1401 did have an add instruction, op code A.--agr (talk) 20:46, 28 November 2010 (UTC)
thread_title:  The 1.4K, 2K, and 4K machines could not compile programs ... 

message: I like completeness and left to myself, will add all kinds of stuff.  But I think details of the 1402 LOAD button do not belong in the article.  Memory, Addressing, Instructions are necessary to understand the 1401.  The function of the LOAD button is a operational nit. Can we delete it?
I'd also delete the existing text about errors, just more operational nits. 69.106.254.246 07:56, 18 September 2006 (UTC)
replies: text: I think bootstrapping is an interesting and usually quirky aspect of any computer. So I think the details of the LOAD button  and typical first-few-instructions discussion should stay. Jeh (talk) 10:50, 3 July 2012 (UTC)
thread_title: 1402 LOAD button

message: The BCD column includes "C", for check bit I assume, but the checkbit also includes any wordmark and so cannot be determined just from the 6 bit character.69.106.254.246 08:14, 18 September 2006 (UTC)
replies: text: You are correct. Nevertheless, that's what's in the IBM manuals. Jeh (talk) 14:33, 17 March 2010 (UTC)
thread_title: Character and Op codes table is wrong

message: Announced as marginal, and for the simple accounting of midrange companies and as a sort of slave print server to the IBM 7090, the 1401 (like many other platforms before it and since) attracted its own hard core of devoted followers, who could see that although marketed as limited in function, the 1401 was in logical terms a real computer, whose secrets could be unlocked by people sufficiently patient to understand its arcane addressing scheme, and to devise ways around its limitations.
I was there, programming 1401's for the US Army, IBM, ... from 1959 to about 1967 and disagree with almost everything in that sentence. So I am a "hard core ... devoted follower", but am I wrong? Did IBM really sell 20,000 marginal machines? 69.106.254.246 06:01, 18 September 2006 (UTC)
thread_title: Announced as marginal...

message: I used to program the 1401 - lots - and I have no idea what that sentence means.69.106.254.246 05:41, 18 September 2006 (UTC)
replies: text: Deleted. Only took 18 months. :) The index register scheme is covered in the next graf. Jeh (talk) 18:24, 18 May 2010 (UTC)
thread_title: An optional "Advanced Programming Option" allowed for additional flags for 3 bytes within the first 100.

message: "An IBM 1401 installation located on Michigan Avenue and Congress Parkway was attacked in 1969 by Red concertgoers to a Sly and the Family Stone concert but the crowd did little damage.-ref-Chicago Tribune, 2 August 1970, Page A1-/ref-"
As best I can find the concert was July 27, 1970 (not 1969 - note the Tribune 1970 date) and the concertgoers were disappointed at the no-show Sly & Family.  If they were "Red" (with a capital "R"!) it would have been because of summer weather in Chicago. Too many mistakes, too little contribution - deleted. 69.106.237.145 (talk) 08:32, 19 April 2011 (UTC)
thread_title: Deleted "...1969 ... Red concertgoers"

message: I deleted it because I don't think it applies. A bit-slice microprocessor, as the term is normally used, is a complete MPU and can be used as such in its own native bit width; or it can be combined with others to implement wider MPUs. The fact that IBM implemented one bit of, say, a BCD adder on a card and then used multiple cards to handle the entire BCD digit isn't really the same thing. Those cards were never intended to be used independently, nor could you have combined eight of them instead of four to implement a wider-bit-width adder. Anyway, a tremendous number of discrete transistor machines, to say nothing of tube machines, did something similar with a card or module implementing some basic function for a single bit. If this means the 1401 is a bit-sliced implementation, then so are they all, and the term loses most of its meaning.  I'll leave the references to the 1401 on the Bit slicing page alone pending consensus here. Jeh (talk) 18:33, 29 April 2011 (UTC)
replies: text: I'll "consent" either way, it's out of my field -- just so that both articles agree. (it's nice to know someone is reading this) 69.106.237.145 (talk) 21:48, 29 April 2011 (UTC)
thread_title:  Link to [[Bit slicing]] deleted 

message: There is reference in the article to the hardware of the logic circuitry but none to the hardware of the memory.  I was a programmer fifty years ago and not an engineer but on the odd occasion when the back was off the machine I'd have a look at the chunks of electronics.  The memory comprised copper cores (very small and torus shaped) - I kept a few in my desk drawer - I wish I still had them!  Anyway the cores were arranged in arrays and had three wires at right angles passing through each.  Quite how they worked I don't know, but clearly the wires had to do with setting the bits on or off and detecting whether they were on or off.  And of course that is why main memory of a computer was called core storage.  It was the standard of the day and I'm not suggesting that the 1401 was special, or even the first, but I think some reference to the memory hardware is called for. I have inadequate knowledge, reference works and literary skill to write it.  Tom1942  19:26, 2 July 2012 (UTC)
replies: text: They're ferrite, not copper... though they may have been copper-colored (more likely rust-colored). How core memory works is well described in the Magnetic-core memory article. Jeh (talk) 20:36, 2 July 2012 (UTC)

text: Well, I added a sentence, with a beg for more info (how many bits per plane, size of the cores, cycle time, was it three- or four-wire?, etc.) in the edit summary. To do more we'd need a reference. Maybe one of the people working on the 1401 restoration project at the Computer Museum in the SF Bay area can point to the right IBM manual. It might even have been scanned and placed online... I feel this machine does deserve significant coverage here, as IBM sold or leased a great many of them and afaik they were the last widely used decimal-based computer. Jeh (talk) 22:02, 15 July 2012 (UTC)
replies: text:  I found some references and added some details. Might be able to find more, but this is a good start. Jeh (talk) 23:44, 15 July 2012 (UTC)
thread_title:  1401 memory 

message: Hello fellow Wikipedians,
I have just modified 2 external links on IBM 1401. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
*Added archive https://web.archive.org/web/20120829025513/http://www.bitsavers.org/pdf/ibm/140x/A24-3315-0_1401customFeatur.pdf to http://bitsavers.org/pdf/ibm/140x/A24-3315-0_1401customFeatur.pdf
*Added archive https://web.archive.org/web/20090218011244/http://bitsavers.org/pdf/ibm/140x/ to http://www.bitsavers.org/pdf/ibm/140x/
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
Cheers.—InternetArchiveBot (Report bug) 19:35, 7 April 2017 (UTC)
thread_title:  External links modified 

message: Hello fellow Wikipedians,
I have just modified 3 external links on IBM 1401. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
*Added archive https://web.archive.org/web/20101105110749/http://www.computerhistory.org/core/pdf/ibm_1401.pdf to http://www.computerhistory.org/core/pdf/ibm_1401.pdf
*Added archive https://web.archive.org/web/20100809033646/http://www.bitsavers.org/pdf/ibm/140x/A24-1403-5_1401_Reference_Apr62.pdf to http://bitsavers.org/pdf/ibm/140x/A24-1403-5_1401_Reference_Apr62.pdf
*Added archive https://web.archive.org/web/20100809033646/http://www.bitsavers.org/pdf/ibm/140x/A24-1403-5_1401_Reference_Apr62.pdf to http://bitsavers.org/pdf/ibm/140x/A24-1403-5_1401_Reference_Apr62.pdf
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
Cheers.—InternetArchiveBot (Report bug) 00:31, 10 November 2017 (UTC)
thread_title:  External links modified 

message: * The IBM 1401 compiles and runs FORTRAN II YouTube February 2, 2018  — Preceding unsigned comment added by 89.25.210.104 (talk) 00:31, 16 February 2018 (UTC)
thread_title:  Videos proposition 

message: The info box needs to be for a computer, not just the CPU.  Bubba73 You talkin' to me? 18:30, 18 July 2019 (UTC)
replies: text: There is Template:Infobox computer hardware, but it's not ideal. Maybe we need an info box for historic computers.--agr (talk) 18:53, 18 July 2019 (UTC)
thread_title:  Info box