VT52s, VT61s lots of DEC and DG keyboards- return trip through Maine, MA, NY, PA, OH, IN to IL

Jon Elson elson at pico-systems.com
Wed Oct 14 10:03:54 CDT 2015

On 10/14/2015 09:00 AM, Paul Koning wrote:
>> On Oct 13, 2015, at 11:27 PM, Jon Elson <elson at pico-systems.com> wrote:
>>>> ...
>> Yes, I had a bunch of Versatec 1200A's with the Tektronix hard copy feature.  the Versatec was the greatest graphics printer until laser printers came out, then they became instant boat anchors.  Here's the process.
>> ...  And, with the Tek hardcopy board, it could hardcopy a Tek storage tube terminal in less than 30 seconds.
> Ok, but for screen hardcopy, the question is how the image on the screen is read out so it can be fed to the printer.  For the Tek storage tube case, that presumably is done by scanning the screen with the beam, which will produce the stored image in the same way as a TV camera tube works.  But how would you do that in a plasma panel?
Actually, the plasma panels used a bistable effect, that was 
how the screen memory worked.  Each pixel would stay lit 
once the discharge was struck.  The drive electronics could 
scan a pixel and tell whether it was lit or not by the 
voltage across the pixel.


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