On 2021-11-23 18:53, Valery Ushakov wrote:
On Tue, Nov 23, 2021 at 09:22:43 -0500, Greg Troxel wrote:I think (memory is getting fuzzy) the problem is that the old terminals had a delete key, in the upper right, that users use to remove the previous character, and a BS key, upper left, that was actually a carriage control character.[... snip ...]I see the same kbs=^H on vt52.vt52 is different. I never used a real vt52 or a clone, but the manual at vt100.net gives the following picture:
Not really different. The VT52 key that you use to delete characters to the left sends a DEL.
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
Yes. And noone would ever be hitting the backspace with the intent of deleting what you just typed. This all originates with the ASR33 actually. There the key was labelled "RUB OUT". And it sends a DEL.
vt100 had similar keyboard (again, never used a real one personally) https://vt100.net/docs/vt100-ug/chapter3.html#F3-2 BACKSPACE 010 Backspace function DELETE 177 Ignored by the VT100
I've used both VT52 and VT100, as well as almost every other model of VT terminal there is.
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).
Correct.
But somehow the official terminfo database has kbs=^H for vt220!
Which is wrong.
Later it became configurable: https://vt100.net/docs/vt320-uu/chapter4.html#S4.13
Yes. It might only have been configurable if you had specific keyboards, but at least it was possible to change for some. But default is still DEL.
For vt320 (where it *is* configurable) terminfo has
$ infocmp -1 vt320 | grep kbs
kbs=^?,
Which I think it should be.
Johnny
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