Registry for terminal DA responses?

Allison ajp166 at bellatlantic.net
Mon Jun 13 07:36:48 CDT 2005


>
>Subject: Re: Registry for terminal DA responses?
>   From: Patrick Finnegan <pat at computer-refuge.org>
>   Date: Sun, 12 Jun 2005 23:22:52 -0500
>     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>Michael Sokolov declared on Sunday 12 June 2005 10:48 pm:
>> My question is: does anyone know if such a registry exists and where
>> can one apply for a DA code assignment?  TIA,
>
>Uhh, registry? Yeah, right.
>
>You can start your own registry, I guess.  If there was one, it was at 
>DEC and only held the codes used by terminals that DEC produced.  
>Boundless now sells VT5xx terminals; they at some point purchased DEC's 
>old terminal line/division/etc.

DEC wrote an internal standard for terminals and it was quite thick
to specify the behavour of escapes and the like.  If you have the 
VT52, VT100, VT102, VT220, VT240 and VT320/330/340, VT420 manuals 
you have a resonable subset of that description.

>
>You do realize, there were terminals that weren't VT100 compatible (at 
>least in their native mode), like Wyse 50/60 terminals, ADM 3/5s, IBM 
>3151s, Televideo 925s, ...  They didn't do the "CSI c" command; they 
>might have had a "DA" method, but I'm doubtful it was the same as what 
>DEC did.
>
>You might try looking at the BSD termcap/terminfo database for a listing 
>of what kind of responses there are.
>
>I'd assume that (non-DEC) terminals that were put in a VTxxx emulation 
>mode responded to that with the same response that a real VTxxx would 
>give.

Believe it or not NONE of the competing terminals tested inside DEC
met more than 90% of the VT100 sequences (as of 1989ish).  They always
broke in some way usually benign but a few would require reset 
(power off/on)  to correct.  The testing was condusted by the same 
group that validated VT100 through VT420 (maybe further) and all
VT emulations that were non terminal (decwindows,VT1200, and the like).

>Any reason you don't want to use the (so-called) "ANSI" vt-100 type 
>sequences or those from, say, a vt525, for your 'termainal application'?

I can think of one.  The average VT100 emulation is poor at best and 
fully broken most times.  Vt100 was a family of terminals, also the 
capability varied so the escape sequences were extended using ANSI 
private.  

The only stuff I've seen that behaves accurately is VT52 emulation, 
mostly because VT52 was so limited compated to VT100.


Allison


More information about the cctalk mailing list