[Simh] Scrambled text in VAXStation 3100m38 GPX graphics screen

[paulhardy2 at btinternet.com]

I've been running the VAXStation 3100m38 simulator with GPX graphics, generally successfully, apart from increasing corruption of the screen fonts through time and use. Attached is a screenshot showing a typical stage after an hour or so as the screen scrambling reaches unuseability, and another one a bit earlier when some windows are good and some are scrambled.

Has anyone else observed this? I think I've seen it happen even if I don't use any applications software - just VMS and Motif. They happen to be VMS 5.5-2H4 and Motif 1.1, but I don't think that is vital. However, popping a graphics window on top and then lowering it so DECTerm etc comes to the front seems to trigger corruption in the Session menu bar, and then it gets worse in other windows - lower case gets scrambled first, then some upper case letters.

I'm running the current pre-built Windows binaries (git commit id: 
52a31597), which I note are now nearing 2 months old (7 May) - the description on Github says that they are rebuilt at least once a week, so is an automated process broken?

Regards,

--
Paul  Hardy
web: www.paulhardy.net

-------------- next part --------------
A non-text attachment was scrubbed...
Name: SimH_GPX_Scrambled_Text_01.png
Type: image/png
Size: 81540 bytes
Desc: not available
URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20190621/3d443a8c/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: SimH_GPX_Scrambled_Text_02.png
Type: image/png
Size: 72075 bytes
Desc: not available
URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20190621/3d443a8c/attachment-0003.png>