15 Apr
2014
15 Apr
'14
4:44 p.m.
On Apr 15, 2014, at 5:49 PM, Gary Oliver <go at aerodesic.com> wrote:
I have the schematics for that. I should see about sending them to Al to put on
bitsavers.
Excellent. I
wasn't aware cyber1.org had a way to handle the 19/10 bit
frames. This gives me incentive. Since I need to build hardware in any
case to handle the keyboard and data to the display (as I said, I
received NO additional hardware) it should be simple enough to just do
some appropriate conversion to TCP/IP there as well and give it an
ethernet connection (l'll likely use a Beaglebone for the task. Kinda
overkill, but easy.)
Should work well. The connection to cyber1 basically takes the 19 bit word and splits it
across 3 bytes of TCP data stream. So all you need to deal with is clocking that out
synchronously to the terminal. It?s actually 21 bits: a start bit (!), 19 bits of data,
parity. The start and parity bits aren?t in the TCP data stream. Words of all zero serve
as filler.
Beaglebone GPIO should have no trouble with this, I would think. If all else fails, a
shift register could be attached.
On 04/15/2014 02:16 PM, Paul Koning wrote:
> On Apr 15, 2014, at 4:50 PM, Gary Oliver <go at aerodesic.com> wrote:
>
>> I have the 'guts' to the earlier Plato terminal (the one with the
>> 512x512 plasma.) By 'guts', I mean the keyboard and display - no box or
>> electronics.
Do you have the plasma panel power supply? I hope so, because that is a pile of esoteric
magic that?s absolutely critical. The functioning of the plasma panel depends critically
on the waveform from the power supply.
...
Magnavox sounds familiar. Our terminal was in a large sheet-metal box
without a micro I'm sure, given the time-frame (mid 1970s.) I looked at
the manuals on bitsavers, but they seem to refer to the video-terminal
variety. ....
2) Does this even make sense? Would one of these connected to the
"Plato Network" vie TCP/IP be able to do the stuff it could do native
(e.g. control the music synth, slide projector, etc.)
Yes, it could be connected.
The ASCII version is very easy to connect. The classic (19 bit) one would take a little
hardware to turn the TCP data stream into the correctly framed synchronous data to the
terminal (and to accept the 10 bit asynchronous terminal output for transmission over
TCP). So it could certainly work with the cyber1.org system.
Thanks for the info. I will research this project further.
Good luck. An additional resource is Aaron Woolfson, who has restored a number of PLATO
terminals and knows them quite well. He?s very busy, but he said I could pass along his
contact information: woolfson at telswitch.com
paul