[.PTY]
These files make up a pseudo terminal driver for VAX/VMS. This driver was
originally developed at Carnegie-Mellon University and has made the
rounds before as the CMU PTY driver.  I picked up the driver just after
it had been migrated from V3 to V4, made a lot of improvements, and have
been redistributing it ever since.

This driver runs under VMS V4 and V5.  It will not work under any VMS
prior to V4.  It has been minimally tested by me on V4.7 and V5.0.  It
should work on earlier V4 point releases as well, but I haven't tried it.

Note that during assembly the driver will detect the version of VMS and
build the proper variant.  You do not need to modify the sources for V4
of V5.

See PTY_DOC.TXT for documentation and NOTES.TXT for my additional comments
and observations.

Changes for version 05-011A (PYDRIVER) and 05-004A (TWDRIVER) include:

  o  The bug causing the driver to sometimes hang on CTRL/S has been fixed.

  o  A bug causing the driver to incorrectly check for XOFF has been fixed.

  o  A bug causing writes of (32 * N) + 1 bytes to fail has been fixed.

  o  Support has been added to immediately return echoed data on
     writes to the PY device.  This can save substantial amounts of
     overhead in some situations by avoiding an extra output read.
     See the example program ECHO_TEST.C.

  o  Support for VMS V5 including Symmetric Multiprocessing environments.
     Conditional assembly of the drivers will produce V4 or V5
     compatible drivers.

  o  The port control MULTISESSION bit is now set by the driver, causing
     terminal sessions on TW devices to NOT count against your license
     limit.  This is good for programs like PHOTO, but not so good
     for network logins.  This really should be made settable by the
     application controlling the PY device.

  o  Writes to the PY device will now return SS$_DATAOVERUN if the TW
     signals XOFF.

  o  There is now a SETMODE and SETCHAR function that allows you to
     enable three new ASTs.  It does not take any function modifiers and
     only sets the specified ASTs.

  o  The TW device now defaults to HOSTSYNC.

  o  The PY device now accepts a SENSEMODE and SENSECHAR QIO function
     to read the device characteristics of the TW terminal device.

  o  Modification to slave terminal device ownership to function
     correctly after "Security Upgrade V2" has been applied to a
     VMS V4 system.  The security upgrade is incorporated into V5.

  o  The PY device now supports writes of buffers greater than 64K.
     Note that use of such large buffers probably requires that you monitor
     the flow control ASTs.

  o  The terminal device name has been changed from TPAn: to TWAn: because
     the VAX PSI product now uses TP.  PY and TW are the names of choice
     now since they have been registered within Digital by a development
     group.

     These drivers should be compatible with the DECwindows PY and TW
     drivers since they derive from the same code.  There may, however,
     be differences that cause DECwindows to not function.  I do not
     know.  I would suggest using the DEC supplied DECwindows versions
     of the drivers if you have it installed.

[.DECWINDOWS]
Well, now that V5.1 and DECwindows is out lets get some VMS DECwindows
related goodies onto this list!

To start things rolling, here's a little hack to allow non workstation hosts,
generally large, multiuser VAXen, to create a DECwindows (DW from now on, my
fingers are tired of that!) LOGINOUT screen on a workstation running just the
server.

When DW starts up it determines if it is running on a workstation or not. If
not, it simply does the things that need to be done on a client-only machine,
not much, and exits.  On a workstation it goes on to start the server and then
create a DW LOGINOUT process which throws up the wonderful "|D|i|g|i|t|a|l|"
logo and the "Username/Password" dialog box.


	/Kevin Carosso                        kvc@friday.a-t.com
	 Innosoft International Inc.          kvc@ymir.bitnet

	April 21, 1989