🚀 go-pugleaf

jensting@ee.ic.ac.uk (Jens Tingleff) writes:

>The screens are marked VR 290 D3 (the computers are VAXstations II/Gpx).

>What we'd like to know is
>	 does anyone have data on the signal that goes into the screens?
>	   (frequencies, interface, where does the Sync go?)

Sure...here is some info which was posted in reply to the my same question
just last week:

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Subject: Re: VR-290 Specs?
Newsgroups: comp.sys.dec
In-Reply-To: <BvrCv7.199@news.cso.uiuc.edu>
Organization: University of Wisconsin - Madison
Cc: 
Status: RO

>From the owner's manual spec sheet (I could have sworn there was
>more last time I looked):

0.31mm dot pitch
1024(horiz)x864(vert)pixels ; 326mmx275mm picture size

Vertical Rate 60Hz
Horizontal Rate 54kHz

Video R+B 0.7Vpp/75Ohm
Video G w/sync 1.0 Vpp/75Ohm

Doug   brune@luther.che.wisc.edu

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X-News: bbs.mdcbbs.com comp.sys.dec:10094

>Is there someone out there who could pass on the following info about
>the VR-290:

Are you sure it isn't a VR299 ? If it is, these may help...

>1, Horizontal and vertical sync frequencies.
>3. Horizontal & Vertical sync pulse width & polarity (I know they are
>   on green).

Horizontal rate timing
freq		54.054 khz
front porch	160 ns
Sync pulse	1850 ns
back porch	1680 ns
blank intercal	3.70 us max

Vertical rate timing
freq		60 Hz
front porch	0 horiz lines
Sync pulse	3 horiz lines

>2. Video Bandwidth

Pixel freq	70 MHz
Pixel period	14.45 ns

Composite video
Red		.7 vpp / 75 ohm
Green (w/sync)	1 vpp / 75 ohm
Blue		.7 vpp / 75 ohm

--
* Mark Rief   =8*)              rief@bbs.mdcbbs.com                 *
* Caco Pacific, 813 N. Cummings Rd, Covina CA 91724  818-331-3361   *

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>	 has anyone (successfuly) used these screens on (gasp!) PC
>	   graphics cards?

Yo!  I'm using mine with an ATI Graphics Ultra with BSDI's BSD 4.3 port at
1024 x 768 resolution.  You can use the utilities and drivers provided
by ATI should you want to to run it with MS Windows.  Remember that there's
no multisync capability...you'll only get garbage before you start up windows.
Also, you'll have to build a little box to straighten out the sync signals.
VGA sends out R, G, B, H-sync, and V-sync on separate lines.  The VR290 
expects sync on green.  For advice and hints about accomplishing this see
"Running VGA on an IBM Professional Graphics Display" in the October/November 
1990 issue of Circuit Cellar Ink, pp. 38-40, by J. C. Hubert.  He also 
discusses hooking up surplus 19" workstation monitors.  If you can't dig
up a copy lemme know and I'll fax one to you.

Have fun!

PS - We've also got an old 19" SGI color display hooked up to a 486 running
as an X-server under windows.  Super monitor for just $250.

>Advice, information, well *anything*, much appreciated

No problem.

-Burr

-- 
   Burr Nelson * 217-333-2435 * burrsie@uxh.cso.uiuc.edu * FAX: 217-244-6615
  U of I Biophysics * 166 Davenport Hall * 607 S. Mathews * Urbana, IL  61801