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From: hans@log-hb.UUCP
Newsgroups: net.unix-wizards
Subject: Re:  VT100 and bagbiting
Message-ID: <183@log-hb.UUCP>
Date: Wed, 4-Jul-84 07:29:32 EDT
Article-I.D.: log-hb.183
Posted: Wed Jul  4 07:29:32 1984
Date-Received: Thu, 12-Jul-84 00:29:04 EDT
References: <1309@sri-arpa.UUCP>
Organization: TeleLOGIC Nyn{shamn SWEDEN
Lines: 55

[]
DC1/DC3 for flow control is NOT mandatory, except in DEC-os'es.

Also, the way EMACS uses C-S and C-Q in no way prevents using the same
characters for ( automated only ) flow control.  However, several terminal
designers tend to take silly shortcuts when it comes to flow control,
such as stopping the TERMINAL output when typing a C-S on the keyboard..
Occasionally similar behaviour occurs on automated control....
In all cases of large institutes buying such braindamaged terminals 
that I'm aware of, the manufacturers finally managed to agree on this being 
wrong, and fixing it. The fixes were easy.

Further I think that it is unreasonable for a terminal that is nominally 
capable of being set for a particular speed, NOT to be able to accept ANY 
sequence of characters at that speed, without flow control. 
An awful example is VT10X'es on VMS, where the aggregate character rate to
the terminal is slightly better at a nominal speed of 4800 than at 9600...
Also, several ( university ) designs have been produced over the past few
years, where any character sequence at any speed up to 9600 can be handled
with NO flow control. All designs in question had full VT100 compatibility
apart from speed capacity.
There is thus no longer any reason to produce terminals without full speed,
non flow-controlled, capacity. 
If flow control is ever nessecary, such as over multiplexed channels, 
electrical signals should be used, to preserve full code transparency.

Of course, any PROGRAM is free to use ANY pair of character sequences for
manual flow control. However, proper screen management is always to be 
preferred.

The misgivings about "Typing ESC characters" can be alleviated ( for EMACS 
use ) by finally making the META-SHIFT facility mandatory. This will be 
done in the ISO standards efforts now underway, they tell me.
EMACS used the ESC character merely for want of a better way, and will
willingly give it up.

Finally, what little research has been put into human interfaces for editors,
seem to indicate that EMACS fares reasonably for any category of users,
and with very little learning effort at that.
The speed gained by just not having to move your fingers off the normal
keyboard is difficult to top without hard training.
The efficient use of separated keypads takes much longer to learn, however,
and will require standardizations of keyboards and codes that we are not yet,
and will hopefully never be, ready for.  The sheer length of the present 
suggestions for codes to be used is abominable. Also the lack of any real
structure is annoying.


-- 
			{decvax,philabs}!mcvax!enea!log-hb!hans
			Hans Albertsson, 
			TeleLOGIC AB
			Box 1001,
			S-14901 Nynashamn,
			SWEDEN