8

The standard cursor movement keys on the TI-99/4, /4A and apparently /8 were Function + E (for up), S (for left), D (for right), and X (for down). These keys were also often used (without needing the function key) for games.

WordStar on CP/M used the same keys, albeit using Control rather than Function (as Function was a somewhat specific key to the TI keyboard). A number of other CP/M and early DOS applications copied the WordStar combinations, so they were quite common for a while.

Was this coincidental, did one of these copy the other, or did they both derive from some common older source that I'm not aware of?

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Was this coincidental, did one of these copy the other, or did they both derive from some common older source that I'm not aware of?

I wouldn't make a bet, but Wordstar is what I would have said as well - or more correct, keyboard layout, as the selection is not an invention out of nowhere, but follows a logic based on common (terminal) keyboard layout.

ESDX (and ESDF for games and DEC alike T-Bar cursors) is the first cursor like location that can be used across various keyboards. These letters are the same on English and German Keyboards (QWERTZ/QWERTY key order) and at least close to each other and as well on the left side for French Keyboards (AZERTY). On terminals, where there is no scan code, but letters and letter wise assigned control codes this avoids the need for country/keyboard dependant command routines - and, equal important, different manuals and key sheets. These three keyboard layouts cover a great deal in Europe and worldwide.

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  • Nowadays the tend to use WASD (pronounced waz dee) instead of ESDF.
    – cup
    Sep 16 '18 at 13:23
  • 2
    @cup: As stated in the answer, the idea was to create a layout that worked on various international keyboards. WASD doesn't form a proper layout on AZERTY keyboards.
    – DrSheldon
    Sep 16 '18 at 18:48
  • 2
    afaik WASD was introduced by quake?
    – Tommylee2k
    Sep 17 '18 at 13:39
  • True. Just, I tried to stay with the question, avoiding to go into a lengthy rant about cursor/fuction handling on alpha keyboards.
    – Raffzahn
    Sep 17 '18 at 13:49
  • I've always pronounced WASD as 'wasst'. :o
    – knol
    Sep 5 at 17:03
5

For wordstar the original diamond was chosen probably because the ctrl key position on a lot of older keyboards made it a natural extension and it can be used by the left hand solo. It also avoid the Ctrl-H and Ctrl-M which would be used for backspace and carriage return. While it's possible that the TI engineers were influenced by Wordstar the dates make that seem a little bit unlikely. (Wordstar is 1978 and the TI is 1979)

As an aside Apple II prior to the Autostart ROM used Esc-A,B,C,D for cursor movement, the Autostart ROM added the I,J,K,M diamond instead (where ESC toggled in and out of movement mode). So the idea of diamond for movement was not unusual.

Wordstar keyboard diamond

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  • 1
    Keep in mind, that Wordstar was made for Terminals, similar everyting TI made before the 99.
    – Raffzahn
    Sep 5 at 11:22
  • Good point I wonder what the standard TI 9xx mini-computers terminal used?
    – PeterI
    Sep 5 at 22:14
  • @Raffzahn: It would have been designed for a direct-connected terminal which would either be capable of responding to data as fast as the computer could send it or have hardware handshaking. The use of control-S and control-Q would make it unsuitable for use on any link that requires xon/xoff handshaking.
    – supercat
    Sep 7 at 16:41

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