Help with Sun video
ard at p850ug1.demon.co.uk
Wed Oct 29 11:28:55 CDT 2008
> >> - Connect monitor directly to workstation with a 13W3 Sync-On-Green
> >> adapter (no passthrough of sync signals): Works fine.
> >> - Connect monitor directly to workstation with a 13W3 adapter that brings
> >> out H+V sync: Works fine.
> > Does this adapater do anything to the green signal? Is it possile that
> > the monitor is still using sync-on-green and ignroing the H and V Syncs
> > from the adapter (if, indeed, they're even active)?
> Not sure what you mean. If there's sync-on-green, it will be there. The
Exactly. I was asking if the adapter somehow separated the sync from the
'green' and passed on only the 'green' to the monitor (this is
technically possible, of course).
> second adapter just happens to pass through H&V sync also. Both work when
> the monitor is connected to the workstation through them. These are
My point is that in both cases the monitor could be using the sync in the
sync-on-green signal and not using the seaprate H and V sync signals
provided by the second adapter. In other words whether the adapter
provides the sync signals might be irrelevant to the monitor, but might,
somehow, affect the swtich.
> > Does this just connect ot the video port on the switch, or to the
> > keyboard and/or mouse ports as well? It wouldn't suprise me if checking
> > for +5V on, say, the keyboard port was part of the 'I have a computer
> > connected' detection.
> It connects to all of the above. I've already heard from just about
> everyone (thanks!) that the +5V keyboard power is what it's looking for to
> activate the port in the first place. One of the things I want to run
> through it is video from one of my Amigas, so it appears I'll need to
> build up a little 5V supply with a keyboard connector that I can use to
> fool that port (since the Amiga 1200 has its own keyboard and mouse).
I thought there was a +5V output on at least one of the Amiga connectors.
But maybe only on some models.
> Sorry. In all cases I'm using a PC-standard VGA-VGA (HD15M-HD15M) cable.
> I'm starting to suspect that the Belkin converter box may be defective, in
> that it appears sync _is_ getting through while video is not. I can't
> think of any other reason why the monitor comes out of standby and yet
> displays a black screen. Will get a scope on it soonish and see what's
> coming out.
This is an LCD monitor, isn't it? I have little experience of those, but
I have seen a video projector that would detect a signal will incorrect
scan rates, but not attempt to display it. Maybe your monitor is similar.
I would try to measure the H and V sync frequencies. It may be (as your
other message implied) that the adapter somehow gets the workstation to
output some scan rate that uour monitor can't handle.
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