Talk:Computer terminal

Green Screen gone ambiguous

The link to Green Screen no longer reaches directly thru to Green_Screen_Display. I'd work harder to fix this but I've forgotten my Wikipedia username. —Preceding unsigned comment added by 67.170.241.65 (talk) 16:05, 15 November 2008 (UTC)

This statement from the article makes no sense

This statement from the article makes no sense: "This class of terminals were later renamed dumb terminals, differentiating them from PCs running emulation software." Terminals have always been differentiated from PCs running emulation software, by actually being terminals. I recognize that some people mistakenly use the term "dumb terminal" to refer to any computer terminal, but isn't that out of ignorance? --Serge 06:41, 12 December 2005 (UTC)

Is the merge actually serious? Command prompt being merged with computer terminal? I almost died laughing. If this goes ahead, we may as well merge the articles on cathode ray tubes and the BBC. Afterall, CRT's display the BBC channels, don't they. Strongly oppose. 82.10.97.111 21:48, 3 September 2006 (UTC)

What is the etymology of this term?

The statement no longer appears in that form; the current version looks reasonable Tedickey (talk) 11:09, 13 November 2008 (UTC)

"little usability of many text-mode applications"

I added citation-needed to the part of the article which states that (interpretation by me):

1. ncurses, terminfo, terminal emulators etc are buggy
2. and so buggy that many applications have "little usability" (i.e. major problems)
3. and all development effort goes into GUIs, so it will probably never be fixed

I use these kinds of applications heavily at work and at home, and I don't recognize this description of reality at all (my only major annoyance is colors, which tend to come in unreadable combinations by default). Furthermore, I have never heard complaints like these raised before, neither by users nor programmers. JöG 15:31, 29 July 2007 (UTC)

I generally see comments such as "buggy" from (a) people who don't know how to select a proper terminal description, or (b) people relating second-hand opinions Tedickey 19:30, 21 September 2007 (UTC)

AlphaWindows

I've added a section on AlphaWindows. I think this is notable since it was a pre-MS-Windows attempt to have multiple sessions on a single screen, however I'm afraid that I can't cite sources simply because so little was published about it (roughly translated: trust me, I'm an engineer :-) I might have one extremely skimpy article on it somewhere but if anybody else has anything (e.g. on what sort of escape sequences it used and how the host operating system saw it) I think it would be of general interest. MarkMLl 18:31, 21 September 2007 (UTC)

1992 isn't pre-MS-Windows. AlphaWindows were a variant such as X Terminal, addressing a lower-end market Tedickey 19:17, 21 September 2007 (UTC)

It was approximately contemporaneous with Windows 3.0, my understanding- but I'm happy to be corrected if you were in some way involved- is that Wyse et. al. intended it to support multiple text- not graphical- sessions, which is why I don't think categorising it as a graphical terminal is appropriate.

When I wrote "pre-MS-Windows" I was specifically thinking of running multiple live terminal sessions under Windows- something that was still rather a novelty in those days. MarkMLl 20:19, 21 September 2007 (UTC)

Celio Technology Corporation

The paragraph appears unbalanced, since it extends a fairly generic description with special mention of a tangentially-related commercial product. If there are "some examples", this probably should be developed first into a general paragraph of their characteristics (contrasting against the existing paragraphs). Tedickey (talk) 00:46, 15 January 2009 (UTC)

I added it because I created the article this afternoon (disclaimer: I have no connection or affliction to the company). As far as I'm aware it's the only product of it's type that's available in the smartphone marketplace - there was suppose to be the palm Folio but that got pulled a week before release. If you are unhappy with it feel free to remove it or rewrite it as you feel fit, however since the paragraph says that dumb terminals have declined in use, I just thought it would be useful to add an example where they are being used in a new way. --Cameron Scott (talk) 01:04, 15 January 2009 (UTC)

Oh I would have linked directly to the terminal itself - the Redfly but em.. I couldn't be arsed to write the article. --Cameron Scott (talk) 01:05, 15 January 2009 (UTC)

What about "thin terminals" (which seem to be merged here with thin client)? Some of those aren't really graphical, since they're advertised as replacements for legacy character terminals Tedickey (talk) 01:09, 15 January 2009 (UTC)

That could be about right - I'm off to bed as it's rather later - if you haven't moved or something when I get up, I'll take another crack at it. --Cameron Scott (talk) 01:12, 15 January 2009 (UTC)

thanks - I think that going in that direction might help Tedickey (talk) 01:23, 15 January 2009 (UTC)

“Text terminals” section

IMHO this section should be splitted to a separate article, merged together with stubs character-oriented terminal and block-oriented terminal. Only a brief general description should remain here. Incnis Mrsi (talk) 16:15, 3 January 2010 (UTC)

Most of this topic is general, covering both. character-oriented terminal and block-oriented terminal happen to be interesting subtopics, but by no means manage to cover the entire topic. Tedickey (talk) 22:53, 3 January 2010 (UTC)

Entire what? “Computer terminal” is a broad topic, too broad to be covered by one article. “Block-oriented terminal” is an narrow subtopic about obsolete hardware, would it be ever expanded to a full article like IBM 3270? May be, but may be not, I don't know. So named “character-oriented terminal” is virtually the most common design of a text terminal (the thing, about what we think as about a text terminal). I can't see any reason to discuss it separately from text terminals in general. “Character-oriented terminal” has no links from articles, except from its counterpart “block-oriented terminal” and through controversial redirect page “Character-cell and block-oriented terminals”. I propose to merge “Text terminals” section with “character-oriented terminal” stub, move the resulting article to Text terminal and fix a redirect “Character-cell and block-oriented terminals”. Incnis Mrsi (talk) 12:15, 5 January 2010 (UTC)

Short - you're proposing to move most of the text-terminal content from this topic to where the existing redirect Text terminal is now? Tedickey (talk) 10:19, 6 January 2010 (UTC)

I think that a separate article “Text terminal” should exist, with a content overlapping with this article. Incnis Mrsi (talk) 20:08, 9 January 2010 (UTC)

dumb vs smart

The text as it is right now does not match my understanding. It is true that a real dumb terminal has limited escape sequence processing (whether the cursor is addressable is one distinguishing feature often used) but terminals like VT100 and so on are not "smart". That is reserved for the record-at-a-time terminals - those that receive a form to be edited and send the results back to the computer once the whole form has been completed. General purpose terminals don't do this and need the smarts of the host computer for the entire editing procedure - move from one field to the next, show what has just been typed, and so on. —Preceding unsigned comment added by Minority Carrier (talk • contribs) 16:14, 31 August 2010 (UTC)

The distinction varies according to the source. For something like this, more than one reliable source (illustrating the variation) would be useful. TEDickey (talk) 20:23, 31 August 2010 (UTC)

Article needs work

There isn't enough discussion of different technologies, e.g. "typewriter-like" ribbon on paper, thermal, electrostatic, or video raster vs. vector. There's no discussion of special-purpose terminals such as data-collection devices. There's no discussion of such devices as remote-batch or RJE terminals. There's no discussion of connectivity - channel-attached, modem-connected, etc. I think the article could use work, but I'm not sure how to organize it. Peter Flass (talk) 22:36, 4 June 2012 (UTC)

Windows terminal emulator not provided

Running telnet in a console window has (for quite a while) used the console api to provide a passable terminal emulator. Checking now on a Windows 7, I see that telnet is an optional feature. By the way, the use of "modern" in topics such as this is a red flag indicating inaccuracies (indeed, most of the statements are unsourced, reflecting their origin in personal opinion). TEDickey (talk) 10:51, 8 September 2013 (UTC)

The suggested stackoverflow link does not address the criticism made (and by the way is not authoritative in any sense) TEDickey (talk) 15:45, 8 September 2013 (UTC)

But I also added the qualifier "ANSI" to "terminal emulator". I'm not sure what kind of terminal the Windows console does emulate, outside of MS-DOS mode (which would not count as "modern Windows"), but if it's not ANSI/VT-100 then it's not very useful, these days.--greenrd (talk) 18:09, 8 September 2013 (UTC)

The comment in the topic which you removed was for Hyperterminal, which was replaced a long time ago by the Windows telnet (since serial connections were not useful), which in turn uses the console api to provide terminal emulation. The telnet program identifies itself as "ansi". So... Windows does provide terminal emulation in this way, and has (if I recall properly) since Windows 2000. By the way, you can also provide a telnet server on Windows7 at least (noted while verifying things earlier). You should be aware that ANSI and VT-100 are not synonymous - they merely overlap substantially. TEDickey (talk) 18:22, 8 September 2013 (UTC)

If you're unfamiliar with the console api, here is one of the pages discussing it. TEDickey (talk) 18:24, 8 September 2013 (UTC)

here is mention of an old version of the telnet terminal description, from 1999. TEDickey (talk) 18:35, 8 September 2013 (UTC)

given the content of the topic as it exists, all that you can say about "ANSI" is whether the terminal uses the ANSI controls (which Windows telnet does...). So I don't see any benefit offered by your stackoverflow link - it is concerned with coloring the prompt, which is only a small part of terminal emulation. TEDickey (talk) 18:40, 8 September 2013 (UTC)

Noting recent edits emphasizing native ANSI terminal emulation bears on this issue. The "ms-vt100" entry described in ncurses' terminal database uses "ANSI" controls, just as do the randomly-selected set of examples (each of which, by the way, has one or more deficiencies with respect to ANSI and/or VT100). Aside from the obvious point that editors wish to make that Windows lacks something, there's apparently nothing to discuss here. TEDickey (talk) 19:44, 20 September 2013 (UTC)

Again, "virtual device" is probably irrelevant (or we have to drop Solaris from the list, as I recall, as well as one or more of the BSD's). Like Windows, OSX lacks a "console" which is what some of the editors are attempting to describe. It provides a terminal emulator instead. So that's half the list gone. TEDickey (talk) 20:39, 20 September 2013 (UTC)

OK, it now says

The Win32 console on Windows does not emulate a physical terminal that supports escape sequences so SSH and Telnet programs (for logging in textually to remote computers) for Windows often incorporate their own code to process escape sequences. On systems that provide terminal emulators that do support escape sequences, such as those on most Unix-like systems, this bundling is unnecessary.

Hopefully that 1) is technically correct in its description of the issue on Windows and 2) avoids randomness.

I'm not sure what the "console" is that you say some editors are attempting to describe. If you're referring to what you get if you don't run a window system, if you log into OS X as >console, it gives you a non-window-system session that I think might support some escape sequences (>console isn't working on my VMware Fusion OS X virtual machines, and I'm not about to log out on my host machine to test it). Solaris also supports such a console, as do FreeBSD, DragonFly BSD, and NetBSD and OpenBSD if you've enabled more than just "dumb". (They might not support multiple virtual consoles, but that's another matter.) Guy Harris (talk) 22:00, 20 September 2013 (UTC)

No, the issue is unresolved. The topic is slanted to prove a point, rather than noting how terminal emulators in Windows actually are supported. We could go on at length, but there's nothing factual that I could use in referring to this page. TEDickey (talk) 22:07, 20 September 2013 (UTC)

Is the current version

The Win32 console on Windows does not emulate a physical terminal that supports escape sequences so SSH and Telnet programs (for logging in textually to remote computers) for Windows, including the Telnet program bundled with some versions of Windows, often incorporate their own code to process escape sequences. The terminal emulators on most Unix-like systems, such as, for example, xterm and [[Terminal (Mac OS X)|], emulate physical terminals that support escape sequences

not such slanted, or does discussing the difference at all constitute trying to prove a point? Guy Harris (talk) 22:11, 20 September 2013 (UTC)

There's still some debris, as would be noticed by someone proofreading the current revision. For instance, the "so" in the first sentence after the tag where this discussion is introduced as indicating a limitation. A neutral phrasing would point out that the Windows console api does not itself perform terminal emulation, but that there are terminal emulators (such as the longstanding Cygwin console from 2000-2010 and the Windows telnet application) which use this api to provide terminal emulation (a difference in approach rather than a deficiency). Keep in mind that this is the Computer terminal topic, not ANSI escape code. On the positive side, OSX console is no longer mentioned (naive readers might not understand that it was unlikely to be something they would use). Also, it's probably fairly easy to source something which points out that the reason for add-on terminal emulators (which again, almost entirely are ssh or telnet clients) is for improved interoperability with various applications, or more convenient user interfaces - GUIs), while noting that analogous programs are far from lacking in the Unix/like platforms. As usual, WP:RS should bear the burden rather than editors writing an essay. TEDickey (talk) 19:32, 21 September 2013 (UTC)

Turing-complete

Recent edit used the term Turing-complete for this, without noticing that the issue of "bounded size" makes it inconsistent. Also, the document doesn't support a "first". Finally of course, the edit is not topical TEDickey (talk) 18:08, 9 February 2014 (UTC)

I've just added a further resource.

Furthermore EVERY physical / real-world machine has limited memory - so if you don't want to drop the idea of Turing-completeness altogether for real-world computers, it's of course an attribute whereby the principal physical limitation is understood by itself.79.230.160.93 (talk) 18:16, 9 February 2014 (UTC)

Real-world computers aren't (except in marketing literature) Turing-complete, because they're necessarily incomplete. You can undoubtedly find some dubious information to support your contention, but neither source pretends to do that. TEDickey (talk) 18:30, 9 February 2014 (UTC)

So are you going to change (for a start) the information presented in the table of the following "dubious"(?) source: History of computing hardware#Early computer characteristics? 79.230.160.93 (talk) 20:53, 9 February 2014 (UTC)

actually, there's enough misinformation on Wikipedia to keep us both occupied. But there's no point to be made in adding to it. WP:OTHERSTUFF is something you should keep in mind TEDickey (talk) 21:35, 9 February 2014 (UTC)

Well, there certainly is misinformation in the Wikipedia, but this is not part of it. My college exam on computability was several years ago - but I remember that in the lecture it was just too obvious that no physical machine is Turing-complete in a strict sense (just like there is no round circle and no right angle in the strict mathematical sense in the physical world) - but it DOES make sense to apply the attributes. Otherwise you would always have to say "theoretically Turing-complete computer" to make the distinction when comparing it to computers that are not "theoretically Turing-complete" ... well, even one over three doesn't exist for real, which I don't mention too often. 79.230.163.75 (talk) 23:07, 9 February 2014 (UTC)

The computer we're discussing was certainly limited, and only by granting unrealistic amounts of memory and tape-size could it be termed "complete". Computer science curricula might be careless about notions like infinity - or poorly understood, at the undergraduate level. TEDickey (talk) 23:55, 9 February 2014 (UTC)

This was not undergraduate level (and by the way, it's not particularly intelligent to infer poor understanding without being specific / disproving a single point made). The Turing-completeness of the other early computers was only proven years after their advent. Hans Hermes wrote an early proof of the Turing-completeness of actually built computers - practical usability was the goal of the early computers, not only of the Z3. 79.230.163.75 (talk) 00:45, 10 February 2014 (UTC)

Furthermore, there's "Turing-complete" and there's "usefully capable of being programmed to make decisions"; the paper cited for the in-principle Turing-completeness-assuming-you-can-make-a-paper-tape-as-big-as-is-necessary of the Z3 says:

I can therefore say that from an abstract theoretical perspective, the computing model of the Z3 is equivalent to the computing model of today's computers. From a practical perspective, and in the way the Z3 was really programmed, it was not equivalent to modern computers.

so the theoretical ability, given enough paper tape, to simulate a Turing machine of an arbitrary size doesn't, in and of itself, make its I/O devices worthy of being categorized as "the first computer terminal". The first terminal for a modern computer was either the buttons, switches, and output CRT of the Manchester Small-Scale Experimental Machine or the teleprinter for the Manchester Mark 1, depending on whether you consider the SSEM to be a proof-of-concept or a real example of a modern computer. The first terminal for a programmable computing device might have been the keyboard and lights of the Z3, unless there was an programmable computing device built before the Z3. Guy Harris (talk) 00:28, 10 February 2014 (UTC)

Ok, that funny link shows to me that you're critical -- have you seen that the Wikipedia article on computers says:

"Alan Turing was the first to conceptualize the modern computer"?

– the idea of the Turing machine can as well be used to build a computer, as it can be used to build a brain, or a universe-simulator, as "well" as Gödel's earlier Turing complete formalism can be used to build real computers -- is it valid to say that Turing first conceptualized the modern computer?

Apropos second part: which one will it be and why that you call the first computer, and therefore the first computer terminal -- and who has detailed information about the Z4? 79.230.163.75 (talk) 01:03, 10 February 2014 (UTC)

"is it valid to say that Turing first conceptualized the modern computer?" It depends on what you mean by "conceptualize the modern computer". A Turing machine is different from a von Neumann machine; the latter concept more closely resembles the way a modern computer actually works. Turing's paper described an abstract machine to perform computations; Gödel's paper doesn't have any similar machine notion, at least not that I can tell, nor does Church's "An Unsolvable Problem of Elementary Number Theory", so, in that sense, one could, I guess, argue that Turing conceptualized some sort of computing machine perhaps not unlike the modern computer. In what would just you just as well use either formalism "to build real computers" (not that many real computers, if any, are built using either formalism)?

Then again, if we're not restricting "conceptualizing the modern computer" to "conceptualizing a von Neumann machine", a case could be made for Charles Babbage.

"which one will it be and why that you call the first computer, and therefore the first computer terminal" I call the SSEM and Mark I the first modern computers (not the first computers, unqualified by the term "modern") because they were the first two stored-program computers where the computer could, in theory, load or write code into memory and run it (i.e., where the human operator was not, by the very architecture of the machine, obliged to hand-load a program into memory (the SSEM may not have had enough memory to hold a program that could load the next program, but that's different from a machine that doesn't run programs from memory at all, or runs them from read-only memory that has to be set up by an operator). The stored-program computer page currently says:

The University of Manchester's Small-Scale Experimental Machine (SSEM) is generally recognized as world's first electronic computer that ran a stored program—an event that occurred on 21 June 1948. However the SSEM was not regarded as full-fledged computer, more a proof of concept that was built on to produce the Manchester Mark 1 computer, which was first put to research work in April 1949. On 6 May 1949 the EDSAC in Cambridge ran its first program, and due to this event, some consider it "the first complete and fully operational regular electronic digital stored-program computer". It is sometimes claimed that the IBM SSEC, operational in January 1948, was the first stored-program computer; this claim is controversial, not least because of the hierarchical memory system of the SSEC, and because some aspects of its operations, like access to relays or tape drives, were determined by plugging.

so:

• if one considers the SSEM the first "modern computer", even though it was a bit small to be a usable computer in practice, its I/O devices would be the first terminal;
• if one considers the Mark 1 the first "modern computer" by virtue of it being big enough to be a usable computer in practice (I'm not sure quite why one would consider the EDSAC "the first complete and fully operational regular electronic digital stored-program computer" if it ran its first program in May 1949 and the Mark 1 ran its first program in April 1949, unless "ran error free for nine hours" means "it didn't finish because the machine failed during the tenth hour"), then its teleprinter would be the first terminal.

The Z4 doesn't count as a "modern computer", as it was programmed with punched tape, at least according to the Wikipedia article about it. Zuse may have come up with the idea of a stored-program computer capable of loading or generating code that it could then execute, but I don't see any indication that he implemented that idea before the Manchester people did (and the reference for that claim in the von Neumann architecture page is to a paper by the Manchester folks that doesn't mention Zuse; this page speaks of "Zuse's 1936 patent application (Z23139/GMD Nr. 005/021)", which appears to be available on-line here, where you can read the first page of the patent application for free, but that doesn't show anything about code coming from anywhere other than a tape, you need to buy the full application which says "The computation plan can also be stored so that the commands can be transmitted to the control device at the computation phase." on the page numbered 166).

If we're not going to restrict ourselves to modern computers, we could go back at least as far as the Z3, but if we're going to do that, I'd be inclined to give examples of I/O devices for other programmable computers, whether they're programmed with punched tapes or punched cards or plugboards or.... Guy Harris (talk) 03:34, 10 February 2014 (UTC)

The Turing "machine" can not be used as a blueprint to build a real computer -- even if the mathematical model is called "machine" ... that was exactly the point: that no computers are built using either formalism. ///

I considered most of these valid points and they surely speak for the computers you mentioned (the Z3 did of course not store programs internally in electronic memory -- but it does implement the stored program concept) ... there are also different characteristics of a modern computer -- referring to the modern use of floating point arithmetic, the Z3 was actually closer. The "Optimizing Compilers for Modern Architectures" book by Randy Allen and Ken Kennedy includes an interesting Figure with a timeline showing Flops/s of the fastest computers, roughly every decade a jump -- from 1KFlops/s (UNIVAC 1) to 1MFlop/s (CDC 6600) and so on. The Z3 is not shown, but it fits: 1 Flop/s a decade earlier.

To give more examples of other I/O devices of early computing systems like you suggest seems to be the best way of handling this history, making it once more clear, that technological progress is usually a gradual evolution. 79.230.128.96 (talk) 10:46, 10 February 2014 (UTC)

this link appears to be a copy of the cited paper (the given doi is WP:PAYWALL not generally accessible), and doesn't differ from the abstract. It doesn't have a corresponding section for the hypothetical "computer terminal" which could plausibly be used to make this thread topical TEDickey (talk) 01:08, 10 February 2014 (UTC)

This very article which we’re dealing with here says:

"A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system."

I've seen the replica of the Z3 in the museum, and I also saw the computer terminal -- it's not hypothetical. 79.230.163.75 (talk) 01:18, 10 February 2014 (UTC)

oh - which of your provided sources said that was a computer terminal? (We're only considering reliable sources; personal experience doesn't count) TEDickey (talk) 01:26, 10 February 2014 (UTC)

The introductory (and obvious) sentence which I quoted in my last post from this very article also has also no explicit reference ...

The frame of the (let's call it) terminal of the Z3 replica was wooden, as we both can see in the photograph and which I saw for real -- but as long as there is no source which explicitly states that -- we can consider it hypothetical, i.e. if personal thinking doesn't count ... 79.230.128.96 (talk) 10:51, 10 February 2014 (UTC)