Monitor adapter?
der Mouse
framebuffer, which drives 1280x1024@72Hz, apparently with no other
options. I'd like to use this framebuffer.
However, practically all the monitors I have are Sun monitors. The
Alpha has 3BNC output, so it must be using sync-on-green; most of my
Sun monitors are 13W3, and I don't know what they do for sync, except
that so far they've always proven compatible with the (Sun) video I
drive them with.
Does anyone know anything about what sort of compatability there may
be? If adapter devices are needed, can they be passive (eg, a splitter
to send green to both green and sync) or need they be active (level
shifter, sync extracter and conditioner, whatever)?
I have a number of Sun monitors on hand, but the only ones which have
BNC inputs (a) appear to be fixed-frequency and (b) use 5BNC, rather
than 3BNC, implying they want separate sync. Some of the others
appear, based on some Sun doc I found on the Web, capable of
1280x1024@76 and thus probably can do 1280x1024@72, but they use 13W3
and, in the one case I found a pinout, appear to want separate sync.
I do have a peecee monitor with a HD15, but given its physical size and
after looking at its screen, I suspect that it can't really do
1280x1024 on the screen even if it accepts the signals.
Any thoughts?
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> I recently picked up an alpha machine, a DEC 3000 300X. It has a
> framebuffer, which drives 1280x1024@72Hz, apparently with no other
> options. I'd like to use this framebuffer.
Most Sun monitors I saw up to now (which doesn't mean a lot) need sync-on-green. Most of the better PC monitors support it - just try to dig up the product description - it's more frequent than you'll expect.
good luck
Michael
Brett Lymn
>
> Does anyone know anything about what sort of compatability there may
> be? If adapter devices are needed, can they be passive (eg, a splitter
> to send green to both green and sync) or need they be active (level
> shifter, sync extracter and conditioner, whatever)?
>
Last I looked at that sort of stuff - the video signal was a positive
voltage and the sync was a negative one, mixing the green+sync was a
matter of a simple or of the two signals. I believe that extracting
the sync is a matter of putting a diode around the right way.... in
fact, I _believe_ that feeding the green signal into both G and sync
probably won't hurt.
--
Brett Lymn
Carl Lowenstein
> From: der Mouse <mo...@Rodents.Montreal.QC.CA>
> Date: Wed, 15 Oct 2003 19:57:24 -0400 (EDT)
> To: port-...@NetBSD.org, port-...@NetBSD.org
> Subject: Monitor adapter?
>
> I recently picked up an alpha machine, a DEC 3000 300X. It has a
> framebuffer, which drives 1280x1024@72Hz, apparently with no other
> options. I'd like to use this framebuffer.
>
> Alpha has 3BNC output, so it must be using sync-on-green; most of my
> Sun monitors are 13W3, and I don't know what they do for sync, except
> that so far they've always proven compatible with the (Sun) video I
> drive them with.
>
> be? If adapter devices are needed, can they be passive (eg, a splitter
> to send green to both green and sync) or need they be active (level
> shifter, sync extracter and conditioner, whatever)?
>
> BNC inputs (a) appear to be fixed-frequency and (b) use 5BNC, rather
> than 3BNC, implying they want separate sync. Some of the others
> appear, based on some Sun doc I found on the Web, capable of
> 1280x1024@76 and thus probably can do 1280x1024@72, but they use 13W3
> and, in the one case I found a pinout, appear to want separate sync.
Back in the days of NeXT computers (another Sync-on-Green video system)
I found that I could use a Sun monitor on a NeXT (i.e. the Sun monitor
would respond to sync-on-green). The converse, NeXT monitor on Sun,
did not work because the Sun did not produce sync-on-green.
A 13W3 to 3 BNC adapter should work.
YMMV
carl
--
carl lowenstein marine physical lab u.c. san diego
clow...@ucsd.edu
Jochen Kunz
> I recently picked up an alpha machine, a DEC 3000 300X. It has a
> framebuffer, which drives 1280x1024@72Hz, apparently with no other
> options. I'd like to use this framebuffer.
>
> However, practically all the monitors I have are Sun monitors. The
> Alpha has 3BNC output, so it must be using sync-on-green; most of my
> Sun monitors are 13W3, and I don't know what they do for sync,
All Sun Monitors made in the last 10 or 12 years are Sony Trinitron
Monitors. These monitors can do Sunc-on-Green. If they have 5 BNC
connectors just connect RGB and that's it. Some of these monitors are
fixed frequency, some are multifrequency most are multisync. Connect the
Alpha to the monitor and you will see if the monitor can do the
frequency. ;-) Normaly it causes no harm to drive a fixed frequency
monitor with the wrong frequency, if you do it only for a few minutes.
If you have a monitor with 13W3 or SubD15 input you can use an adapter.
I have Sun and SGI multisync monitors and I use them for everything,
Sun, SGI (including SGI monitor on Sun machine and vice versa), Alpha,
PMAX, HP9000, RS/6000, ...
--
tschüß,
Jochen
Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/
der Mouse
> All Sun Monitors made in the last 10 or 12 years are Sony Trinitron
> Monitors. These monitors can do Sunc-on-Green. If they have 5 BNC
> connectors just connect RGB and that's it.
Unfortunately all my BNC-input monitors are the very old Hitachi
monitors, the ones that date from the Sun-3 era. What doc I have
managed to find (based on their 365-xxxx numbers) implies that they are
entirely monofrequency. I suppose I should try them, though.
However, someone (someone local to me, even!) wrote off-list offering
me a 3BNC<->13W3 adapter, which it sounds as though ought to make it
all work for me.
Paul Kranenburg
> monitors, the ones that date from the Sun-3 era. What doc I have
> managed to find (based on their 365-xxxx numbers) implies that they are
> entirely monofrequency. I suppose I should try them, though.
Heh, did you power them up lately? Every Hitachi monitor I've ever seen
has long since exploded..
-pk
der Mouse
The 5BNC ones, no - though one of them worked fine last time I tried to
use it, some years back. But I have a 13W3 Hitachi that I had on just
a day or two ago. It has convergence problems - the blue has drifted
about a pixel lower than the other colours - but it's otherwise fine.