DEC VRE01 terminal documentation - test-drb@ccmp.vtda.org

13 Aug 2020

Here's a photo of one of the restored PLATO terminals (which had the plasma display)
Does the power supply for the PLASMA look like the one in this photo of one of the
terminals with the covers off?

  ----- Original Message ----- 
  From: Aaron Woolfson 
  To: paulkoning at comcast.net ; uban at ubanproductions.com ; cctalk at classiccmp.org 
  Sent: Thursday, August 13, 2020 1:50 PM
  Subject: Re: DEC VRE01 terminal documentation

  Hi Tom.

  Thanks for your message.  Well, the Plasma panels use a pretty unique.  I'm
attaching the precise waveforms that the Plasma Panel expects to see in order to achieve
the illumination of the dot. And while this may not be exactly or precisely what
you're looking for, this will explain much about the technology involved.  The fact
that you can see any illumination at all is perhaps the most important part - beacuse the
gas is probably there, and the "actuation" voltage might just not be high
enough, or the sustainer voltage might have an issue.

  The power supplies were manufactured by Electro Plasma and were typically separate from
the actual unit itself.  I am going to see whether I can find the schematics for those
power supplies, which discuss the characteristics .

  Also, check to see whether the back of the plasma panel itself has an edge connector
that is similar to the attached TYCO specified connector. That might give you some
insights into where to go.  

  When I gave all my equipment and test gear to the LCM up in Seattle, I am pretty sure
that they also got a lot of the original manuals and notes that had been hand written. 
But I typically had scans of most everything.  I will see what I can find....

  ----- Original Message -----
  Subject: Re: DEC VRE01 terminal documentation
  Date: Thu, 13 Aug 2020 16:38:39 -0400
  From: Paul Koning <paulkoning at comcast.net>

  You may want to see if the PLATO terminal documentation is any help, look on Bitsavers
under University of Illinois.  Those plasma display power supplies are hairy devices; the
panel is actually a memory device and the power supply produces a high voltage AC waveform
to make that work.  Those panels normally light up around the rim; the fact you see that
briefly but not sustained gives some hope that adjusting may be all that is needed.

  That's quite a display; the usual plasma panels were 8 inches square, 512 by 512
pixels.  I'm guessing this is a 1k by 1k pixel display, which I have seen once or
twice, at SAI in San Diego in some military displays.

  I know a plasma terminal expert; I've forwarded your message to him.

  paul

...
  On Aug 13, 2020, at 3:23 PM, Tom Uban via cctalk
<cctalk at classiccmp.org> wrote:

 I have a DEC VRE01 terminal that I bought NIB years ago. For those who don't know
about this model,
 it has a flat plasma (orange/black) display of about 17". It worked when I bought
it, but now, years
 later, I tried powering it up and the light comes on for a moment and goes out. I suspect
a power
 supply issue, but bitsavers does not seem to have this one.

 Does anyone have schematic (or other) documentation for it?

 --tnx
 --tom 