pr@cl.cam.ac.uk (Peter Robinson) (07/19/90)
We have a server for X10.4 that runs under XDE. This is written entirely
in Mesa, using none of the X code distributed from MIT, and uses the
standard XDE TCP/IP support. This has been in use for a three or four
years now and is stable and reliable, if slightly incomplete. We routinely
use it to access microVAXes in our distributed computing system from
Daybreaks. The performance is quite acceptable (better than a monochrome
VAXstation) but has occasional hiccups which we attribute to quirks in the
underlying TCP/IP code.
The server is rather complicated because it places all the X windows inside
XDE windows. This means that all the usual XDE tools continue running and
using the input system in their ordinary way while the X clients elsewhere
believe that they are talking to an ordinary X server.
This is allied with a simple XDE tool and a Unix daemon that allow an XDE
user to cause a named Unix machine to run an xterm connected on one side to
a login shell and on the other to an X connection back to the XDE machine.
Thus an XDE user can log on to an arbitrary Unix machine with little effort.
We never quite got round to upgrading it to X11. All our other
workstations are now running X11.4, but we have retained an X10 version of
xterm, so at least we can run terminal sessions from Daybreaks. I do not
beleive that there are any great intellectual difficulties in upgrading the
server, just a certain amount of tedium. We also wanted to install XDE 6.0
before doing any further work, but that has been rather slow arriving.
We have not given much thought to making the server available under
ViewPoint but, given the TCP/IP code, I imagine that there would be no
great difficulties.
If you are interested in integrating Xerox workstations into a Unix
environment, you should also be aware of some other pieces of software that
we have written. We have an XNS-SMTP mail gateway running under XDE using
the Foreign Gateway Assistant, although this is about to be superseded by
running Alpine on a nearby Sun. We also have tools for XDE and InterLisp
that allow network news to be read from Unix servers using the remote read
news protocol, and a number of utility tools to handle rwho transmissions
and so on. Finally (but nothing to do with Unix), we have a mail-fax link
running through a Xerox 7021 fax machine; sending faxes as electronic mail
is extremely popular, receiving them is a bit slow.
Back on the original question, you might care to check on Cal Poly's X11
server project which Jeff Weinstein was working on. This involved
rebuilding an XDE bootfile with X windowing instead of XDE windowing. He
had two main problems: it was slow and not very stable. Jeff has now left
Cal Poly University, but I think the source code might be available from
the Xerox UGP office (if it still exists).
- Peter Robinson.
University of Cambridge Telephone: +44 223 334637
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