From: josephkwok@hgrd01.enet.DEC.COM ("KWOK Wai Ting, Joseph  09-Apr-1992 0953")
Subject: RE: Questions about DECWindows under VMS
Organization: The Internet
Date: Thu, 9 Apr 1992 06:23:07 GMT

>>I have a few questions about DECWindows under VMS that hopefully
>>someone can help me answer.

I think I can answer just a few of them, in fact, I am not experience enough for
answering question on DECWindows under VMS

>>I don't have access to any machines running DECWindows under VMS, so
>>I'm kind of working in the dark here.
>>
>>1)  The information that I've seen implies that DECWindows under VMS is
>>an X11 varient, but I haven't been able to find the relationship
>>between various versions of DECWindows and the releases of X11.  Is
>>there an easy way to tell whether a version of DECWindows is X11R3 or
>>X11R4?

As far as I know, the current distributed DECWindows under VMS is X11R4, I don't
know how to ask for the answer at command level, so I think you better refer to
the release notes or find some Xlib function that is in R4 but not R3 and try
to compile on the platform.

>>2) Is VMS DECWindows a full X11 distribution?  Does it support all of
>>the XLib toolkit?  Are there any other toolkits that are always
>>included?

VMS DECWindows is not a full X11 distribution, at least those mit clients are
not included (at least not in standard distribution), but are there any other
source for those application? I don't know.  But since we have the X server,
we may start those application at an UNIX machine and set the display to the
VMS DECWindows X server.
The Xlib of VMS DECWindows support all the mit standard distribution (I think,
because I still haven't encounter any Xlib function call that is not there).
But, there are obvious different server extension supported since the display
hardware is different.
VMS DECWindows also contain Motif 1.1.1 which we call DECWindows Motif 1.0
We have the Xt (X Toolkit), Mrm (Motif Resource Manager), Xm (Motif) and
DXm (DECWindows Motif Extension) and there is also one old toolkit call
DWT (DECWindow Toolkit which is base on the old XUI style)

>>3) Is there any easy way for X programs running under VMS (with the
>>DECNet protocol, I suppose) to communicate with X servers running under
>>Unix? (either Ultrix or otherwise)

It is very easy to do so, if your UNIX system supports decnet and your X
application is linked with a Xlib which supports decnet then everything is fine
and you just need to "setenv DISPLAY hostname::0.0" where hostname is the DECNet
node name of the VMS DECWindows X server.  If you use the MIT standard
distribution, just build the tree with the file $(TOP)/config/site.def including
the macro #define ConnectionFlags -DTCPCONN -DUNIXCONN -DDNETCONN
where DNETCONN is the flag for compiling with the DECNet protocol.  Of course,
you need your X application linked with the DECNet library.

>>4) Are there any special issues that have to be addressed in porting an
>>XLib-based program from Unix to VMS?

Generally, you should aware of the include header path or any filename used
in the program and also the use of environment variables since VMS uses logical
instead.  If you have a POSIX environment in your VMS system, then, it is much
more easy but of course, you need to pay the penalty of the slow performance of
POSIX environement under VMS.

>>Thanks for your time,
>>
>>Warren

You are welcome!

Regards,
Joseph


Xref: sparky comp.windows.x:9656 comp.sys.hp:5018