a unique problem

robert w. jackman (jackman@sprcore.bih.harvard.edu)
Wed, 8 Feb 1995 19:01:28 -0500


I have what I think is a unique problem and am going to put it before the
collected thought process of this group. I am running a QuickCam on a PowerMac
6100, with system 7.5. When I first got the camera and installed the QuickCam
system I had a normal picture. Some days later I disconnected the QuickCam and
installed the Apple Geoport Adapter and Express Modem hardware and software.
When I reconnected to the QuickCam the picture was quite different, washed out
and mostly just gray in all but the very lowest light levels. I should say that
when I first set up the modem on the 6100 I played around with running the
QuickCam from the printer port and it had Appletalk on at that time. The
installation came back with an error message that it wouldn't be able to run but
installed anyway. I have checked and the problem is the same using the printer
port as on modem. I even removed 7.5 and installed 7.1.2 with the same result.
If I disconnect the QuickCam and run the modem it works fine. I do notice that
if I turn the roomlights very low and let it run for a while it develops more
contrast gradually, but the picture is quite grainy. Most importantly, If I
move the same camera to a PowerMac 7100 it gives a completely normal picture. I
have even set up the modem on the 7100 and it does not cause a problem. Is it
possible that some kind of damage has been done to my VRAM? Is there any way to
test for this, and are there other explanations that fit these data better?

Bob Jackman