On Tue, Nov 23, 2021 at 18:37:19 -0500, Greg Troxel wrote: > Valery Ushakov <u...@stderr.spb.ru> writes: > > > vt52 is different. I never used a real vt52 or a clone, but the > > manual at vt100.net gives the following picture: > > > > https://vt100.net/docs/vt52-mm/figure3-1.html > > > > and the description > > > > https://vt100.net/docs/vt52-mm/chapter3.html#S3.1.2.3 > > > > Key Code Action Taken if Codes Are Echoed > > BACK SPACE 010 Backspace (Cursor Left) function > > DELETE 177 Nothing > > That is explaining what the terminal does when those codes are sent by > the computer. That is a different thing from how the computer > interprets user input.
No. Or rather not only. Please, read the sentence before that table. The "code" column is the code that the terminal transmits when the key is pressed: Table 3-4 lists the function keys, the code they transmit to the host, and the terminal action taken if the code is echoed back to the terminal. > When using a VT52 on Seventh Edition, for example one pushed DEL to > remove the previous character, and the computer woudl send > "<BS><space><BS>" to make it disappear and leave the cursor left. One > basically never pushed BS. It dawned on me that the terminals I used on the pdp-11 clone were (not surprisingly) vt clones and managed to find a picture of the keyboard, which jogged my memory: http://www.leningrad.su/museum/show_big.php?n=1539 so yeah, you would use DEL key on those to correct your typing mistakes. > > But vt200 and later use a different keyboard, lk201 (and i did use a > > real vt220 a lot) > > > > https://vt100.net/docs/vt220-rm/figure3-1.html > > > > that picture is not very good, the one from the vt320 manual is better > > > > https://vt100.net/docs/vt320-uu/chapter3.html > > > > vt220 does NOT have a configuration option that selects the code that > > the <X] key at the upper right corner sends. It's always ^? (\177). > > So that is the "DEL" key, not the BS key. See, this is exactly why I said "<X] key" - because DEL and BS are loaded names that are also used as the names of ascii codes and then there's codes generated by the keys and what terminal does when it receives them. Hence all the confusion. Let's say: "kbs" is the code sent by the <- key, whatever the keycap looks like. -uwe