mark@unix.computer-science.manchester.ac.UK (Mark van Harmelen) (06/13/89)
I have a problem with my unmaintained 1186:
When I boot (from the hard disc, or from a floppy) the screen
initially looks as one would expect, then after some random time
the something takes several lines of pixels and replicates them
above and to the right of where they should be, thus:
white aaaaaaaa
aaaaaaaaetc
white bbbbbbbb
bbbbbbbetc <- each of these bands occupies a vertical
space of about an inch on the screen. The
condition starts at the top and continues
to near the bottom of the screen.
This problem cropped up after I used an XDE utility to boot XCL and run a
3.6 meg lisp image while, for other reasons, I had my machine configured
for a mem size of 1.1 meg (silly me). At that time the EEPROM "decided" to
"spontaneously" set the screen size to a small display rather than a large
one; so some wierd stuff has gone on. The machine is now reconfigured
sensibly and the problem above still persists.
Today I again tried to boot the machine and for the first time there was a
repeated flickering between a sensible display and a corrupted display as
described above. My intuitions are that I smell a hardware problem which
possibly is involved with the display addressing logic, but on the other
hand I seem to remember that xerox-model workstations do screen display via
microcode. A friendly xerox person has suggested reloading the initial
microcode via OthelloTool under XDE, but I don't think that the machine
will stay up long enough to do that.
Anyway, haven't I ruled the init ucode out as the fault by showing
that the display problem exists no matter what kind of disc
(hard/floppy) I boot from?
Any help, hints, leads, etc will be much appreciated.
Thanks,
mark
display parameter to a