A real-time text editor is a program which facilitates editing text. In the process, the text is displayed on a screen, and the displayed text is updated after each key press.

A commonly cited example is the addition of "^R mode" to TECO which was done circa 1972. Previous to this, TECO would only update the displayed text when the user typed Altmode (ESC) to execute entered commands.

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    Doesn't any kind of editing on a 3270 meet this definition? Commented May 19, 2020 at 10:47
  • @MichaelGraf, it's not quite what in mind, but you have a good point. Commented May 19, 2020 at 11:56
  • @MichaelGraf Sort of. My understanding is that much of what a 3270 did was in block mode - make changes and send/process as a block. So there is an immediate visual update but it is more like half-duplex on a TTY than a real-time update. Commented May 19, 2020 at 14:02
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    @manassehkatz-Moving2Codidact - Indeed. The 3270 receives a screenful of text, including mark-up (which areas can be edited), and displays it. The user then locally edits what's on the screen, and the changes are only sent back to the mainframe when the enter key is pressed. This means that the core part of what Lars defines as real time editor functionality ("text is displayed on a screen, and the displayed text is updated after each key press", + cursor movement and such) is contained in the terminal firmware, not in some editor application. Commented May 19, 2020 at 14:20
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    I had another editor in mind, called IMEDIT. It's very much like the 3270 in that the text buffer resides in an Imlac core memory, and updated text is only sent to a PDP-10 host computer when the user types XMIT PAGE. So if IMEDIT would be a real-time editor, there's no reason editing on a 3270 wouldn't be too. Commented May 21, 2020 at 19:26

4 Answers 4


I think the following early text editors meet your criteria:

  • Brian Tolliver’s TVEdit (Stanford, 1965), based on Doug Engelbart’s earlier word processor; see On-line Text Editing: a Survey:

    TVEDIT is one of the earliest (1965) time-sharing, CRT-based text editors [12, 22]; it displays many lines of text at electronic speed. The user thus continually views the most recent version of his text and does not have to constantly refer to a mocked-up copy. Users ordinarily create and maintain text without any hard copy, not even an initial hand-written draft.

    Because of careful user engineering, the simple TVEDIT command language is almost invisible to the experienced user. A control shift button alters the interpretation of alphanumeric keys to perform required functions. A request for these functions can be preceded by a number to repeat the command that number of times. Commands are executed as they are typed, so the user never has to press an execute command key and is seldom forced to wait for a system response.

  • Fred Wright’s E (Stanford, 1970), which helped inspire EMACS;

  • TECO’s CtrlR mode, implemented by Carl Mikkelsen and then re-implemented by Richard M. Stallman, resulting in EMACS (1976);

  • Larry Tesler’s Gypsy (Xerox PARC, 1975), an early GUI-based, modeless editor.

See also A personal history of modeless text editing and cut/copy-paste, Evaluation of text editors, and Design case study: the bravo text editor.

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    It's amazing how this quote celebrates features that are completely taken for granted today. See the current state of the document as you type it! Displays multiple lines of text! Create and maintain text without a hard copy! Control + an alphanumeric key gives easy access to special commands! Commented May 19, 2020 at 20:01
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    As someone who was saddled with only a line editor in school, I was thrilled the first time I could use an up arrow or down arrow key in a text editor...
    – mannaggia
    Commented May 19, 2020 at 20:17
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    Though vi holdouts seem unconvinced by the benefits of modeless editing :-)
    – dave
    Commented May 19, 2020 at 23:38
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    Apropos of nothing: the thing that finally got me to give up my trusty DEC VT52 in favor of the nastier-feeling VT100 was seeing an editor showing the select range in inverse video. OK, game over, VT52 loses.
    – dave
    Commented May 19, 2020 at 23:40
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    Here's a reference card to TVEDIT's commands exhibits.stanford.edu/feigenbaum/catalog/pf238dv0503 Commented May 20, 2020 at 7:48

You might be interested to read about the oNLine-System developed throughout the 1960s and demonstrated by Douglas Engelbart in The Mother Of All Demos (demonstrated Dec 1968), which I believe contains real-time text editing.

  • Thank you. I agree it does show real-time editing. Commented May 19, 2020 at 12:01
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    Technical writers, journalists, and marketing guys should be forbidden from using the words "genius", "revolutionary", "paradigm-shift", etc. until after they have watched, internalized, and understood this demo. Moore's Law has given us a 1000000000000000 times increase in computing power since then, so today's software should be able to do 1000000000000000 as much, but in reality, some of the stuff in that demo still doesn't exist today in a reasonable form. Commented May 19, 2020 at 19:29
  • @JörgWMittag - you missed our "patent lawyers" :-)
    – dave
    Commented May 19, 2020 at 23:46
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    @JörgWMittag, to understand the impact of the demo, you'd have to understand the historical context; what the previous state of the art was. Commented May 20, 2020 at 5:26

I think the most correct answer to this question may actually be here in this link, link, searching for words like "edit" "text" or "writer" .

Also, people replying to the question linked to this one claim the following 2 computers would of been capable 1st link and 2nd link, although there's no evidence it was done in terms of a full alphabet and keyboard etc .

Another possibility or answer to this question ( too difficult to find information on ) is that the 'earliest real-time text editor' ( displaying on a crt ) may in no way have been connected to a computer, it may have simply been some sort of simple electromechanical system containing a video-memory somehow using something like Charactrons ( Charactron, Typotron, Monoscope, and the very earliest the Monotron ) with the video memory just storing coordinates linked to a specific character ), all done without a computer, but using a keyboard, or some other similar method but not using things like Charactrons but using some other type of video memory.

Also not forgetting the Motograph patented in 1923 link, the rolling text adverts up on buildings made of light-bulbs, individual letters were placed in frames on a conveyor belt which touched electrical contacts .

For the PDP-1, the first machine was actually delivered in 1959, there seems to have been a crt ( publicised with the tv type crt screen in 1959 ), which displayed text.

I used to have a much higher quality photo of the text on the crt, where you could magnify it and see the font, but now I can only find the image below, and also the image without the text.

The images shown below, are from the following sites -
- information and photos
- photo

I have no further information about the text on the PDP-1 crt, although maybe it's related to the above mentioned TVEDIT .

You may already know about the following question, not sure if it's a duplicate, which includes a question and information ( in the comments ) about some radar screens which displayed text, and a machine in the late 1940's - First computer to have interactive text on a CRT?

The Whirlwind computer in 1949
Quote from this website webpage "Whirlwind went operational in 1949. It was the first digital computer capable of displaying real time text and graphics on a video terminal, which was an oscilloscope screen."

Searching for keywords like "whirlwind" "crt" "text" "editor"gets results like this link


Also -
- the small desktop sized, crt screen calculator, Friden EC-130 of 1963, which was then copied by other companies .
- the IBM 2260 of 1964 ( information and photo , wikipedia page )

enter image description here

enter image description here

  • Thank you. These are interesting, but it's unclear whether there's a text editor program involved displaying the text. Commented Jun 2, 2020 at 6:59
  • Were those letters drawn as a raster, or as vectors, or by steering the beam through letter-shaped holes in a metal plate before steering the letter-shaped beam to the desired location on the CRT surface?
    – supercat
    Commented Jun 2, 2020 at 17:33
  • I couldn't find if the text was raster or vector, however it seems maybe the reason why you hardly ever see the PDP-1 with this tv type of crt is that it may have been "The PDP-1A prototype as depicted in Datamation" ( a quote from masswerk.at/rc2016/10/01.html ). Re your comment "steering the beam through letter-shaped holes in a metal plate before steering the letter-shaped beam to the desired location on the CRT surface", many months ago I found a patent ( or patents ) for that, however it was for tv-station-broadcasting not for computers I think .
    – mnml
    Commented Jun 2, 2020 at 22:17
  • I'm thinking your comment on the duplicate-? question regarding radars "some RADAR displays had two sets of deflection controls, so that the beam would first pass through a selectable aperture within a plate and then from there be aimed at the proper position on the screen" must have been very difficult for a machine/computer to assign text-characters to individual radar-detections especially when they got too close to each other, they would get objects/detections on radar mixed up, note, transparencies ( using ink that would glow when it was hit by the electron-beam ) also existed
    – mnml
    Commented Jun 3, 2020 at 0:05
  • Systems using metal stencils ( or other methods ) inside the crt to create text on the the crt screen, were the Charactron, Typotron, Monoscope, and the very earliest the Monotron, from the book books.google.es/…
    – mnml
    Commented Jun 4, 2020 at 2:38

If by program you go with the more generic definition that would be a procedure by which something is done, I would have to say that it was probably a stick and clay tablet. It was definitely more forgiving to corrections than the hammer and chisel on stone 'program' and tended to be more portable than the stick and sand 'program' that came before it. :)

One could consider punch cards to be a real time text editor.

  • If you redefine program to mean procedure and then redefine screen to mean a piece of card and then redefine text to mean holes then this does indeed work. Completely changing the meaning of all the key words in a question does make most of them easier to answer. Commented Jun 4, 2020 at 8:51
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    Hey, don't knock those ol' punch cards... It was easy to move lines of text around in your "document"... And they usually had the text for the codes printed on the top of the card also... Commented Jun 5, 2020 at 18:13

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