Re: wsvt25 backspace key should match terminfo definition

["Koning, Paul" <Paul.Koning%dell.com@localhost>]

> On Nov 23, 2021, at 12:53 PM, Valery Ushakov <uwe%stderr.spb.ru@localhost> 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 spent a lot of time on VT52, VT100, and VT2xx terminals.

All DEC terminals have a "delete" or "rub out" key, which transmits 0177.  VT52 and VT100 also have a backspace key, which transmits 010.  VT2xx (LK201 keyboard) do not have that key.  Or rather, they do have a top row function key that is sometimes labeled BS but it sends an escape sequence, and is not taken seriously by most DEC programmers.

DEC software convention always was that the delete/rubout key is how you erase the previous character.  Backspace was never used for that, and there wasn't any obvious reason to have it on the keyboard.  It is, of course, an output formatting character.

	paul