[comp.windows.x] GPX screen flutter

dm@genie.UUCP (06/04/88)

we have a GPX microvax II running Ultrix 2.0-1 and recently loaded X11R2.
everything seemed to be going fine but on occasion, usually when doing a 
lot of screen ops (such as running bitmap), a weird flutter would occur
that distorted the entire screen.  it reminded me of when i used to live 
under an air traffic lane and the jets would wreck our TV picture for 
a few seconds on close passes.  hitting CR would usually restore it.

the arguement about whether this was software or hardware
raged for a couple of weeks and was recently resolved by our DEC field
engineer:  hardware.

for anyone who might still have this problem it was in the VCB02 
video controller module.  specifically we had Rev.B1 on the 
M7169 board.  replacing it with Rev.D3 made the problem disappear.

even the DEC folks back east were counseling their engineer
that it was software, but he persevered and we are happy with the result.