Talk:IBM 1401
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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)
I have registered with spinoza1111 and all contributions should appear under this userid.
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[edit] IBM 1401: fixed I/O memory
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?
I also have a good memory of SPS, the assembler programming language, and recall writing the manual on the "Sterling Hardware Feature", almost universally installed in the UK, This used the Move Characters and Edit instruction, which was incorporated into the design to allow users of non-decimal currencies and weights and measures to write commercial programmes simply.
David Collins
dscollins@dsl.pipex.com
In the early 1970s, Computer Technology Inc. had a data center in Arlington, TX, that included several large System/360 computers, along with a S/360 Model 30 connected to one of the large machines through a channel as a peripheral device, solely to use its 1401 Emulator. Tom O'Brien
[edit] Software
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)
[edit] The 1.4K, 2K, and 4K machines could not compile programs ...
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)
- Good, I always felt that needed clarification. However I didn't have any details myself. -- RTC 20:16, 17 September 2006 (UTC)
Thanks for cleaning up the wording; knew that I hadn't done the complete job; my style seems to be collect first, polish later. The details are all from online manuals via one of the external links, not the kind of stuff I would trust memory for. btw, I seem to see your tracks wherever I go. 69.106.254.246 23:07, 17 September 2006 (UTC)
[edit] 1402 LOAD button
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)
[edit] Character and Op codes table is wrong
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)
[edit] Announced as marginal...
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)
Found IBM announcemet day material. Inserted some text from that and deleted the "marginal" paragraph as unsupported!69.106.254.246 20:16, 18 September 2006 (UTC)
[edit] An optional "Advanced Programming Option" allowed for additional flags for 3 bytes within the first 100.
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)
