15 Sep
2013
15 Sep
'13
12:38 p.m.
Fred wrote:
Seems plausable. Finding or making some sort of DA15 breakout device might be
useful to track it down. Disconnecting each of the keyboard and mouse signals
in turn might reveal if one of those is responsible. Just putting a scope on
them might show which is a likely culprit. However, knowing which signal is
responsible won't help much unless it can be disconnected permanently. There
are keyboard and mouse connectors on the system unit of some models of
VAXstation 3100 but not on the VAXstation 2000.
Regards,
Peter Coghlan.
>I have a
BC18Z I have for connecting the VAXstation to the monitor, keyboard
>and mouse. With this cable, a red hue across the whole screen flashes on and
>off about once a second, the other colours are fine and the screen is
>legible. There is also a thin dark line that scrolls up the screen
>continuously. This happens on two different monitors. I don't think it is
>the VAXstation itself either, because swapping with another cable the
>problem goes away.
On Sun, 15 Sep 2013, Peter Coghlan wrote:
Me too!
I have a VAXstation monitor cable that does that too or something very
like it.
Would that be an issue that DC/continuity checking does not reveal
problems at higher frequencies, such as inductive coupling between wires,
etc.?
I tested continuity of the red wire and it seems
fine. Are there any
components in the keyboard and mouse connector block that could cause this?
It's been a while since I looked at the problem and I don't know where the
cable is now. I think I did a DC comparison between the bad cable and a
working cable and failed to find any difference.
Unfortunately, the only solution I could come up with was the same one you did,
use a different cable :-(