Path: utzoo!attcan!uunet!husc6!bloom-beacon!mit-eddie!ll-xn!ames!pasteur!ucbvax!VENUS.YCC.YALE.EDU!LEICHTER
From: LEICHTER@VENUS.YCC.YALE.EDU ("Jerry Leichter ", LEICHTER-JERRY@CS.YALE.EDU)
Newsgroups: comp.os.vms
Subject: re: Why does EVE switch the terminals WRAP setting off ?
Message-ID: <8805231918.AA22869@ucbvax.Berkeley.EDU>
Date: 19 May 88 16:29:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 35


	I have a SET TERM/WRAP in my login-file, and it works nicely: it
	switches the terminal to AUTO WRAP mode. But, whenever I get into EVE
	and back out, it leaves the terminal with auto wrap off. That is
	annoying. Is that a bug or a feature ?

	I am using VMS 4.2 and the TPU/EVE which comes with it. This happens
	both on a real DEC VT240 and on a Falco 5220 = cloned VT220.

EVE - well, TPU - turns autowrap on the terminal itself off because having it
on interferes with TPU's ability to control what is on the screen.  Ideally,
it should restore the previous setting when finished - but there's a problem:
There is no way to tell what the previous setting was on a VT200!  (The VT300
series terminals can be interogated to determine such things, but no the
VT200's.)

I think you understand this, and are setting the terminal /WRAP in the belief
that this will tell VMS that you want them to turn autowrap on - just as
setting the terminal /APPLICATION_KEYPAD tells them VMS that you want the
keypad set to application mode.  However, that is NOT what /WRAP means at
all.  Rather, it is a request that VMS ITSELF wrap lines that are too long;
it provides no information to VMS about how you want your terminal set up.

Actually, a combination of /WRAP with autowrap in the terminal makes little
sense:  Unless you are doing something unusual, the terminal will never see
any lines long enough to trigger its autowrap facility - VMS will have already
wrapped them.

There is no way of telling VMS that you want autowrap enabled on the terminal.
As a result, it will always end up turned off when you exit from TPU, unless
you somehow arrange to turn it back on again yourself.  (This could be done
by having a surrounding command file - or even a program that invokes callable
TPU - which sends out the appropriate escape sequence once TPU is done.)

							-- Jerry