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From: Provan@LLL-MFE.ARPA
Newsgroups: mod.computers.vax
Subject: re: screen manager
Message-ID: <8511280900.AA15544@ucbvax.berkeley.edu>
Date: Wed, 27-Nov-85 11:53:00 EST
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Posted: Wed Nov 27 11:53:00 1985
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TPU doesn't use SMG$ for several reasons:

1.  They were ahead of SMG$ development.
2.  They had to make it effecient or the project would get scrapped.
2a. TPU has more knowledge about what's been changed on the screen than
	the more general SMG$ would, so they can update faster.
3.  If it supported foreign terminals they wouldn't be able to sell
	as many of their overpriced, underfunctioned VT100s.

In fairness, though, future releases of TPU are supposed to support
SMG$ terminals by using the SMG$ data base, so although they won't
actually be using SMG$ to print the screen, they should be able to
support foreign SMG$ terminals.

The utilities I've found that seem to use SMG$ are VMSmail and the
debugger.  Both have amusing reactions if you try to run them with
a ScrFt style foreign terminal.  VMSmail just chokes and exits.
The debugger chokes, flushes typeahead, but then continues to run.

My biggest complaint about SMG$ is that it tries to map all terminals
into a VT100.  For example, my terminal has insert/delete line, but
not scrolling regions.  VT100s have the reverse.  SMG$ makes no effort
to provide scrolling region support for terminals with only insert/delete
line, even though it's not too difficult.  But since it is some extra
effort, they won't do it, making SMG$ virtually useless for those terminals.
On the other end of the scale, there are terminals which are muchc more
sophisticate than the VT line.  Some have common concept, such as more
memory for display than what goes on the screen.  I don't expect DEC
to support such things, but that's still what you have to do if you're
really serious about supporting foreign terminals.  What I see so far
is "we'll support any terminal at all, as long as it emulates VT100s."

I just wish they have a few people somewhere in development with some
foreign terminals.  This BS in 4.2 that means I have to switch back and
forth between a ScrFt terminal and a SMG$ terminal to run Monitor or
VMSMail is absurd.  I'd be embarrassed (unless, I suppose, what I really
wanted was to discourage people from buying non-DEC terminals).

							provan@lll-mfe.arpa