10 May
2007
10 May
'07
2:57 p.m.
Curt @ Atari Museum wrote:
I could post up the source code for the Atari Plato
cartridge, Vincent
Wu was the coder and he worked directly with CDC on fully
understanding how the actual Plato Terminals worked and wrote a pretty
impressed compression system to take the 512x512 screens and get them
down to 320X192 but also had a zoom feature to allow the Atari to
scroll around and view the full 512x512 screen. Also he
implemented all of the touchscreen routines to work with the Atari
joysticks as well.
While this is all 6500 compiler code and specifically for the Atari
800,XL/XE platform, it may offer some insight.
When I was attending UIUC from
89-93, the PLATO terminals (the 80's era
slanted boxes with the cream sides and the black-ish front) were still
in heavy use in the Physics and Chem areas. However, since we were
typical undergrads and waited until the last minute to finish the PLATO
lessons, the terminals were always crowded, and Loomis Lab was locked up
at 8 or so, meaning the terminals ere unavailable after that.
During the 90-91 year, I stumbled upon a Commodore 64 software
implementation of the base PLATO system, which could connect the servers
using the university dialup (333-1100 or something). It was very
impressive, as it ran at 2400 bps (tough to do on the C64) and rendered
a good 320x200 representation of the 512-512 plasma graphics. It even
replicated the orange-ish color of the screens.
Sadly, I have not been able to locate the disk here since I left
college. I'd love to locate a copy though. I did not know about the
Atari cart, but I suspect the C64 version was probably some port of that
code, since they shared a common CPU. It may have been a unlicensed
port, since I've never seen an actual C64 pot listed anywhere.
Jim
--
Jim Brain, Brain Innovations (X)
brain at jbrain.com
Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times!
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