[comp.sys.dec] DECWindows and twm

te07@edrc.cmu.edu (Thomas Epperly) (07/21/89)

I have a DECstation 3100 running DECwindows(Ultrix Worksystem Software 2.0
I haven't gotten the patch yet), and I would like to replace dxwm with twm
or awm.  After some work I got both twm and awm to compile, but neither
works correctly.  They both have trouble with the Session manager window.
awm complains "Unkown property 75".  The symptoms are kind of hard to
describe, but I will try.  It is like the Session manager's window becomes
part of the background.  If I move the Session manager window it moves
away, but a copy remains where it used to be.  This copy cannot be
selected, moved, or iconified.  This happens with both twm and awm.

Please let me know how to fix this if it can be fixed.  When the
advertising says that the DECstation uses X, I assumed that it could
compile and run X software available on the networks(comp.sources.x).
Also, it would be really nice if they included an appropriate imake in the
distribution.

Tom Epperly
Chemical Engineering
Univ. of Wisconsin-Madison
epperly@chewi.che.wisc.edu
epperly@osnome.che.wisc.edu
te07@cs.cmu.edu

hartzell@boulder.Colorado.EDU (George Hartzell) (07/21/89)

In article <5586@pt.cs.cmu.edu>, te07@edrc (Thomas Epperly) writes:
>I have a DECstation 3100 running DECwindows(Ultrix Worksystem Software 2.0
>I haven't gotten the patch yet), and I would like to replace dxwm with twm
>or awm.  After some work I got both twm and awm to compile, but neither
>works correctly.  They both have trouble with the Session manager window.
>awm complains "Unkown property 75".  The symptoms are kind of hard to
>describe, but I will try.  It is like the Session manager's window becomes
>part of the background.  If I move the Session manager window it moves
>away, but a copy remains where it used to be.  This copy cannot be
>selected, moved, or iconified.  This happens with both twm and awm.
>

I'm running twm on a Decstation 3100 without any problem, but am not
using the session manager.  I am using xdm, which (sortof) qualifies
as a session manager I guess.  I haven't had any problems with it.
Let me know if you want more info.
g.
George Hartzell			                  (303) 492-4535
 MCD Biology, University of Colorado-Boulder, Boulder, CO 80309
hartzell@Boulder.Colorado.EDU  ..!{ncar,nbires}!boulder!hartzell

bph@buengc.BU.EDU (Blair P. Houghton) (07/22/89)

In article <5586@pt.cs.cmu.edu> te07@edrc.cmu.edu (Thomas Epperly) writes:
>I have a DECstation 3100 running DECwindows(Ultrix Worksystem Software 2.0
>I haven't gotten the patch yet), and I would like to replace dxwm with twm
>or awm.  After some work I got both twm and awm to compile, but neither
>works correctly.  They both have trouble with the Session manager window.
>awm complains "Unkown property 75".  The symptoms are kind of hard to
>describe, but I will try.  It is like the Session manager's window becomes
>part of the background.  If I move the Session manager window it moves
>away, but a copy remains where it used to be.  This copy cannot be
>selected, moved, or iconified.  This happens with both twm and awm.
>
>Please let me know how to fix this if it can be fixed.  When the
>advertising says that the DECstation uses X, I assumed that it could
>compile and run X software available on the networks(comp.sources.x).
>Also, it would be really nice if they included an appropriate imake in the
>distribution.

Two possible obvious problems:

	1.  You are running a different version of X.  Around here,
	we have various machines running X10R4 and X11R2, and
	in a month or so we may get X11R3.

	    Generally, the differences between R* versions is in the
	library, Xlib.  As I recall, Ultrix 2.0 comes with X10R4.
	Almost all of the currently snarfable code in the *.*.X groups
	is X11, probably R3.  I don't know if there's any reliable
	method of determining a program's requirements, other than
	trying to compile it and run it.

	    You'll need to install Ultrix 3.0, (and then the
	upgrade/revision Ultrix 3.1, since it's there to fix some bugs,
	and who needs those?), to get X11 installed and twm to
	run.

	    It's interesting that they compile but don't run, isn't
	it?  That's because a lot of the Xlib routines operate by
	interpreting data.  For instance, you can specify "expose"
	as an argument to a (ficticious) XDoSomethingToWin() function,
	or "iconify", and the like.  The XDoSomethingToWin() function
	must be able to recognize what "expose" and "iconify" mean.
	Since they are arguments to a function, there is no checking
	for their semantics when compiling, only that they have type
	(char *), so the program compiles.  Different versions of X may
	have different versions of XDoSomethingToWin(), in which one
	may not implement the "iconify" action.  When you compile a
	program written for a version of X different from yours, a
	program which does use "iconify" as an arg to XDoSomethingToWin(),
	and link it with your Xlib, your version of the
	XDoSomethingToWin() function may get confused.

	    Luckily, almost all Xlib routines have intelligent error
	messages, and a policy that implements them uniformly.  Otherwise
	you'd only get such garbola as "Segmentation Fault" and such,
	or "unknown error in XDoSomethingToWin", which is even worse,
	since I for one would be tempted to debug it.

	2.  I dunno.

An opinion (or four):
	
	twm is a pig.  We have it around here (it's X11 only, as far as
	I know) and it really sucks up virtual memory and cpu time.  I
	don't have to run finger to know when twm-lovers are on the
	system.  It has a few snazzy bells and whistles, but I still
	prefer the sleek efficacy of uwm.  awm never thrilled me,
	either.  dxwm is marginally slower and heavier than twm,
	though, so you can actually see an improvement.

				--Blair
				  "...but I hold forth..."

alex@wolf.umbc.edu (Alex Crain) (07/22/89)

		[twm + DECWindows on a PMAX]

>					 The symptoms are kind of hard to
>describe, but I will try.  It is like the Session manager's window becomes
>part of the background.  If I move the Session manager window it moves
>away, but a copy remains where it used to be.  This copy cannot be
>selected, moved, or iconified.  This happens with both twm and awm.

	I'm running a PMAX with the Xmfb server and the MIT clients. There 
appears to be a bug in the server that causes it to "lose" pixmaps, which
then float on the display, altough you can't touch them. The biggest
hassle with this is that these pixmap images are on the surface of the display,
and thus obscure other images.

	My favorite (well, not really) is when the clock image gets lost. THe
result is that the clock gets obscured by an old pixmap, so time stands still.
Of course, since the covering image looks exactly like xclock, you don't
find out until you realize that it's been 3:15 for the last 4 hours :-).

#################################		:alex.
#Disclamer: Anyone who agrees   #    University of Maryland Baltimore County
#with me deserves what they get.#	alex@umbc3.umbc.edu
#################################	alex%nerwin.UUCP@umbc3.umbc.edu

joel@pandora.pa.dec.com (Joel McCormack) (07/24/89)

There was a horrible region bug in the first release of the DECStation 3100
server.  The bug was actually lurking since time immemorial; my faster
region code just happened to depend on a certain boolean reflecting reality,
which it didn't.  The most obvious symptom of this bug was lost screen
areas: some area on the screen would become ``on top'' of everything else,
and whatever was last there remained there forever.  This behavior did not
ever seem happen using dxwm, but it happened with uwm and its descendants.

In any case, this bug should be fixed in the Ultrix 3.1/UWS 2.1 maintenance
release.

- Joel McCormack (decwrl!joel, joel@decwrl.dec.com)