26 May
2005
26 May
'05
7:21 a.m.
>>>> "der" == der Mouse <mouse
at rodents.montreal.qc.ca> writes:
>> You could probably make a coincident-voltage
memory from
>> them... but they'd be slow I think, but pretty.
> Not all that slow. The first plasma panels -- invented at the
> University of Illinois and used in the PLATO system terminals --
> used the display pixels as memories.
der> Yes-- and they were pig-slow. (I used PLATO in the late '70s,
der> and even then it felt slow to me.)
Don't confuse the capabilities of the display with that of the comm
system. PLATO terminals used 1200 baud comm lines, though with
efficient encoding they would do 180 characters per second (not 120 as
with ASCII) and 60 vectors per second.
The panels could do far more. The second generation PLATO terminal
was an 8080 based device (the first generation was hardwired) and
supported local execution of downloaded programs. Those would go
dramatically faster. Even that show CPU would display text at 3000
characters per second, and that was limited by the 8 bit nature of the
CPU (it would do block erase twice as fast, since there the CPU
interface allowed 16 bits to be touched at a time -- and the panel was
probably substantially faster than that).
paul