Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ucbvax!GRIN1.BITNET!MCGUIRE
From: MCGUIRE@GRIN1.BITNET ("The Sysco Kid ", McGuire,Ed)
Newsgroups: comp.os.vms
Subject: re: Why does EVE switch the terminals WRAP setting off ?
Message-ID: <8806161728.AA27758@ucbvax.Berkeley.EDU>
Date: 10 Jun 88 21:40:32 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 29

I can shed additional light on the TPU/EVE versus terminal wrap question.

The I/O manual states that terminals with hardware wrap on are not supported.
Any wrapping to be done is done by the terminal driver, by inserting a newline
where necessary.  The terminal driver does this if the VAX/VMS wrap
characteristic is turned on.

There is a design error in VAXTPU's handling of both the terminal's hardware
wrap and the VAX/VMS wrap characteristic.

VAXTPU saves and turns off the VAX/VMS wrap characteristic, and also turns off
the terminal's hardware wrap just in case, to avoid obvious screen management
problems.

The error is that, if the VAX/VMS wrap characteristic is on, VAXTPU restores
that characteristic and also sets the terminal's hardware wrap on when exiting.
This causes strange behavior in other screen applications that assume that the
hardware wrap was always off.  Appendix B of the _VAX TPU Reference Manual_,
VAX/VMS Version 4.4, documents this behavior as if it were not a design error.

I wrote an SPR calling the information in the I/O manual to Digital's attention
and asking them to correct the design.  It took lots of clarifying phone calls
to make the problem clear to Digital's SPR response team. (If you are confused
at this point you at least understand why it took so many phone calls! :-)

Despite my efforts, VAXTPU still turns hardware wrap on if the VAX/VMS wrap
characteristic is on, at least in Version 4.7.  I never got a satisfactory
answer to my SPR.

Ed