SUMMARY: Can one SPARC display to two monitors identically?

From: SJ Higa (
Date: Sat Jan 21 1995 - 18:56:44 CST

Original post:

> I've been given the task of setting up a SPARC 20 for a demo
> tomorrow. Unfortunately, the people doing the demo want to be
> able to display to two monitors attached to ONE workstation.
> I've installed a second frame board and monitor but am unable
> to display to both screens simultaneously. Is this even
> possible? I have tried using "openwin -dev /dev/cgsix0 -dev
> /dev/cgsix1" but this just makes the second screen an extension
> of the first. What I'm looking for is a way to make both screens
> display the same images.


There wasn't enough time for me to try any of the proposed solutions
before the demo. But I'm grateful to all who responded. This may be
useful in the future. Basically, there are hardware and software
solutions--most respondents favored the hardware solution.

Hardware solutions

Most respondents favored using either a splitter cable to send
the output of one frame buffer to two monitors or a multiplexer
box for several monitors. Sources mentioned included Inmac, NuData,
and your local audio-video dealer.

For monitors with BNC connections, Jochen Bern suggested to
> Take two Monitors with BNC Connectors. They usually have Connectors
> both for Video in and Video out. Just loop the Signals from one
> Framebuffer through the first Monitor into the second.

For certain Sony monitors, Lyndon Lim mentioned that
> some of the sonys have a video output where you can tap off and
> feed to the second monitor.

Software solutions

The most frequently mentioned software were xmx and xwatchwin.

For users of X11R5, Simon Bellan offered the following:
> The way to do that with X11R5 is to have the following line in it.
> xinit -- /usr/local/X11R5/bin/Xsun.multi -dev /dev/cgsix0:/dev/sgsix1
> You should be all set.

My thanks to all who responded:

"Tim Cuckston" <> (Garry Perratt) (Leonid Kogan)
bern@TI.Uni-Trier.DE (Jochen Bern)
"Faisal Waheed" <waheed@symbol.COM>
fmrco!ocean! (Simon Bellan) (Chris Ciolorito) (Daniel F. Kamm) (Mark S. Anderson) (John Hearns - System Manager)
Steve Young <syoung@cs.Buffalo.EDU>
Steve Young <syoung@cs.Buffalo.EDU> (Orville Aldrich 267-6916) (Ricardo Davis [ESRI-Redlands]) (Lyndon C. Lim)

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