SUMMARY: screendump driving me crazy!

From: AVD Boogaart (
Date: Wed Aug 12 1992 - 10:17:23 CDT

Hi all,

here for a summary on my original question why my screendumps messed
up so often.
I got a massive reply, all very helpful. I knew about the BUG, but could
not think of the tiny clock being so powerful.
A thank you to all who replied, you've been very helpful once again.


One of the things to remember with screendump is that it requires a static
screen, i.e. nothing in motion, while the frame buffer is parsed. If you
have something as simple as clock with blinking : or sweep second hand, you
will get just exactly the behaviour you described. Remove or hide the
clock, and don't touch the mouse during the sceendump and you should start
getting clean printouts again.
Quoting from the screendump manual:

         The output file or the screen may be corrupted if the
         frame-buffer contents are modified while the dump is in progress.

Special thanks go to: (Peter Samuel) (Mark Holm) (Ian MacPhedran)
Dieter Muller <> (Scott Huitt 407-796-2969)
leg@gov.inel (Lance Eric Greenwade)
todd@CA.McMaster.Eng.flex (Todd Pfaff)
John Hasley <hasley@edu.bgsu.andy>

Other replies were:

From: Mike Raffety <>
Try sending screendump into a FILE, then screenload-ing it; the two may
be in serious resource conflict, both trying to access the screen at the
same time. Another good workaround would be to access your FORTRAN
compiler through an rlogin on the one that DOES work reliably and quickly.
& sorry Mike, but the output from the FORTRAN program is graphic and
& needs gfxtool (yes, suncore is out of date, I know, but the program
& is pretty handy on a machine without OpenWindows); hence its output
& need be displayed on the machine with the compiler

From: (Ian MacPhedran)
Do you know what frame buffer this is using? My users are having the
same problems on a 4/260 with a cgtwo frame buffer. It may be a problem
with the particular model of frame buffer. This is the only machine in
our area which has a cgtwo. All others are cgthree, cgfour, or cgsix {or
monochrome/grey}. It is also the only one which demonstrates this problem
to any extent.

From: Dieter Muller <>
Also, you only say you have a colour display. Exactly what sort of
framebuffer is involved? I suspect that since you're running 3.5,
it's one of the older ones, all of which generally work OK. Now if
you had something like a cgtwelve, I wouldn't be surprised at the
world breaking....

From: (David Blackman)
I don't know if this will help you but I've successfully used a program
called dumpregion to produce screendumps of a rectangular window
specified with the mouse. The c-source code can be found on

From: rick (Rick Mott) <rick%pgt1@EDU.Princeton>
Once again, PBMPLUS will help you out here. It has a laserjet filter...



+-----------------------------+---------------------------------------+ | Aad van den Boogaart | e-mail: | +-----------------------------+---------------------------------------+ | St. Georges Hospital Medical School (University of London) | +-----------------------------+---------------------------------------+ | Division of Biochemistry | phone : +44 (0)81 672 9944 | | Cranmer Terrace | ext : 55809 | | London SW17 0RE | fax : +44 (0)81 672 4864 | | United Kingdom | | +-----------------------------+---------------------------------------+

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