<s>
PLATO	B-Operating_System
(	O
Programmed	B-Operating_System
Logic	I-Operating_System
for	I-Operating_System
Automatic	I-Operating_System
Teaching	I-Operating_System
Operations	I-Operating_System
)	O
was	O
the	O
first	O
generalized	O
computer-assisted	O
instruction	O
system	O
.	O
</s>
<s>
Starting	O
in	O
1960	O
,	O
it	O
ran	O
on	O
the	O
University	O
of	O
Illinois	O
 '	O
ILLIAC	B-Device
I	I-Device
computer	O
.	O
</s>
<s>
By	O
the	O
late	O
1970s	O
,	O
it	O
supported	O
several	O
thousand	O
graphics	O
terminals	O
distributed	O
worldwide	O
,	O
running	O
on	O
nearly	O
a	O
dozen	O
different	O
networked	O
mainframe	B-Architecture
computers	I-Architecture
.	O
</s>
<s>
Many	O
modern	O
concepts	O
in	O
multi-user	O
computing	O
were	O
originally	O
developed	O
on	O
PLATO	B-Operating_System
,	O
including	O
forums	O
,	O
message	B-Application
boards	I-Application
,	O
online	B-Application
testing	I-Application
,	O
email	O
,	O
chat	O
rooms	O
,	O
picture	O
languages	O
,	O
instant	B-Application
messaging	I-Application
,	O
remote	O
screen	B-Protocol
sharing	I-Protocol
,	O
and	O
multiplayer	O
video	O
games	O
.	O
</s>
<s>
PLATO	B-Operating_System
was	O
designed	O
and	O
built	O
by	O
the	O
University	O
of	O
Illinois	O
and	O
functioned	O
for	O
four	O
decades	O
,	O
offering	O
coursework	O
(	O
elementary	O
through	O
university	O
)	O
to	O
UIUC	O
students	O
,	O
local	O
schools	O
,	O
prison	O
inmates	O
,	O
and	O
other	O
universities	O
.	O
</s>
<s>
Rights	O
to	O
market	O
PLATO	B-Operating_System
as	O
a	O
commercial	O
product	O
were	O
licensed	O
by	O
Control	O
Data	O
Corporation	O
(	O
CDC	O
)	O
,	O
the	O
manufacturer	O
on	O
whose	O
mainframe	B-Architecture
computers	I-Architecture
the	O
PLATO	B-Operating_System
IV	I-Operating_System
system	O
was	O
built	O
.	O
</s>
<s>
CDC	O
President	O
William	O
Norris	O
planned	O
to	O
make	O
PLATO	B-Operating_System
a	O
force	O
in	O
the	O
computer	O
world	O
,	O
but	O
found	O
that	O
marketing	O
the	O
system	O
was	O
not	O
as	O
easy	O
as	O
hoped	O
.	O
</s>
<s>
PLATO	B-Operating_System
nevertheless	O
built	O
a	O
strong	O
following	O
in	O
certain	O
markets	O
,	O
and	O
the	O
last	O
production	O
PLATO	B-Operating_System
system	I-Operating_System
was	O
in	O
use	O
until	O
2006	O
.	O
</s>
<s>
PLATO	B-Operating_System
was	O
either	O
the	O
first	O
or	O
an	O
earlier	O
example	O
of	O
many	O
now-common	O
technologies	O
:	O
</s>
<s>
Screen	O
software	O
sharing	O
:	O
,	O
used	O
by	O
instructors	O
to	O
help	O
students	O
,	O
precursor	O
of	O
Timbuktu	B-Protocol
.	O
</s>
<s>
Flight	O
Simulation	O
:	O
;	O
this	O
probably	O
inspired	O
UIUC	O
student	O
Bruce	O
Artwick	O
to	O
start	O
Sublogic	O
which	O
was	O
acquired	O
and	O
later	O
became	O
Microsoft	B-Operating_System
Flight	I-Operating_System
Simulator	I-Operating_System
.	O
</s>
<s>
3D	O
Maze	B-Application
games	O
:	O
,	O
based	O
on	O
a	O
story	O
by	O
J	O
.	O
G	O
.	O
Ballard	O
,	O
the	O
first	O
PLATO	B-Operating_System
3-D	O
walkthru	O
maze	B-Application
game	O
.	O
</s>
<s>
To	O
wit	O
,	O
if	O
computerized	O
automation	B-Application
increased	O
factory	O
production	O
,	O
it	O
could	O
do	O
the	O
same	O
for	O
academic	O
instruction	O
.	O
</s>
<s>
Bitzer	O
,	O
regarded	O
as	O
the	O
Father	O
of	O
PLATO	B-Operating_System
,	O
recognized	O
that	O
in	O
order	O
to	O
provide	O
quality	O
computer-based	O
education	O
,	O
good	O
graphics	O
were	O
critical	O
.	O
</s>
<s>
In	O
1960	O
,	O
the	O
first	O
system	O
,	O
PLATO	B-Operating_System
I	O
,	O
operated	O
on	O
the	O
local	O
ILLIAC	B-Device
I	I-Device
computer	O
.	O
</s>
<s>
It	O
included	O
a	O
television	O
set	O
for	O
display	O
and	O
a	O
special	O
keyboard	B-Device
for	O
navigating	O
the	O
system	O
's	O
function	O
menus	O
;	O
PLATO	B-Operating_System
II	I-Operating_System
,	O
in	O
1961	O
,	O
featured	O
two	O
users	O
at	O
once	O
.	O
</s>
<s>
The	O
PLATO	B-Operating_System
system	I-Operating_System
was	O
re-designed	O
,	O
between	O
1963	O
and	O
1969	O
;	O
PLATO	B-Operating_System
III	I-Operating_System
allowed	O
"	O
anyone	O
"	O
to	O
design	O
new	O
lesson	O
modules	O
using	O
their	O
TUTOR	B-Language
programming	I-Language
language	I-Language
,	O
conceived	O
in	O
1967	O
by	O
biology	O
graduate	O
student	O
Paul	O
Tenczar	O
.	O
</s>
<s>
Built	O
on	O
a	O
CDC	B-Device
1604	I-Device
,	O
given	O
to	O
them	O
by	O
William	O
Norris	O
,	O
PLATO	B-Operating_System
III	I-Operating_System
could	O
simultaneously	O
run	O
up	O
to	O
20	O
terminals	O
,	O
and	O
was	O
used	O
by	O
local	O
facilities	O
in	O
Champaign	O
–	O
Urbana	O
that	O
could	O
enter	O
the	O
system	O
with	O
their	O
custom	O
terminals	O
.	O
</s>
<s>
The	O
only	O
remote	O
PLATO	B-Operating_System
III	I-Operating_System
terminal	B-General_Concept
was	O
located	O
near	O
the	O
state	O
capitol	O
in	O
Springfield	O
,	O
Illinois	O
at	O
Springfield	O
High	O
School	O
.	O
</s>
<s>
It	O
was	O
connected	O
to	O
the	O
PLATO	B-Operating_System
III	I-Operating_System
system	O
by	O
a	O
video	O
connection	O
and	O
a	O
separate	O
dedicated	O
line	O
for	O
keyboard	B-Device
data	O
.	O
</s>
<s>
PLATO	B-Operating_System
I	O
,	O
II	O
,	O
and	O
III	O
were	O
funded	O
by	O
small	O
grants	O
from	O
a	O
combined	O
Army-Navy-Air	O
Force	O
funding	O
pool	O
.	O
</s>
<s>
By	O
the	O
time	O
PLATO	B-Operating_System
III	I-Operating_System
was	O
in	O
operation	O
,	O
everyone	O
involved	O
was	O
convinced	O
it	O
was	O
worthwhile	O
to	O
scale	O
up	O
the	O
project	O
.	O
</s>
<s>
Accordingly	O
,	O
in	O
1967	O
,	O
the	O
National	O
Science	O
Foundation	O
granted	O
the	O
team	O
steady	O
funding	O
,	O
allowing	O
Alpert	O
to	O
set	O
up	O
the	O
Computer-based	B-Operating_System
Education	I-Operating_System
Research	I-Operating_System
Laboratory	I-Operating_System
(	O
CERL	O
)	O
at	O
the	O
University	O
of	O
Illinois	O
Urbana	O
–	O
Champaign	O
campus	O
.	O
</s>
<s>
In	O
1972	O
,	O
with	O
the	O
introduction	O
of	O
PLATO	B-Operating_System
IV	I-Operating_System
,	O
Bitzer	O
declared	O
general	O
success	O
,	O
claiming	O
that	O
the	O
goal	O
of	O
generalized	O
computer	O
instruction	O
was	O
now	O
available	O
to	O
all	O
.	O
</s>
<s>
The	O
PLATO	B-Operating_System
IV	I-Operating_System
terminal	B-General_Concept
had	O
several	O
major	O
innovations	O
:	O
</s>
<s>
Touch	B-Device
panel	I-Device
:	O
A	O
16×16	O
grid	O
infrared	O
touch	B-Device
panel	I-Device
,	O
allowing	O
students	O
to	O
answer	O
questions	O
by	O
touching	O
anywhere	O
on	O
the	O
screen	O
.	O
</s>
<s>
The	O
Gooch	O
Synthetic	O
Woodwind	O
(	O
named	O
after	O
inventor	O
Sherwin	O
Gooch	O
)	O
,	O
a	O
synthesizer	O
that	O
offered	O
four-voice	O
music	O
synthesis	O
to	O
provide	O
sound	O
in	O
PLATO	B-Operating_System
courseware	O
.	O
</s>
<s>
This	O
was	O
later	O
supplanted	O
on	O
the	O
PLATO	B-Operating_System
V	I-Operating_System
terminal	B-General_Concept
by	O
the	O
Gooch	O
Cybernetic	O
Synthesizer	O
,	O
which	O
had	O
sixteen	O
voices	O
that	O
could	O
be	O
programmed	O
individually	O
,	O
or	O
combined	O
to	O
make	O
more	O
complex	O
sounds	O
.	O
</s>
<s>
Bruce	O
Parello	O
,	O
a	O
student	O
at	O
the	O
University	O
of	O
Illinois	O
in	O
1972	O
,	O
created	O
the	O
first	O
digital	O
emojis	B-Application
on	O
the	O
PLATO	B-Operating_System
IV	I-Operating_System
system	O
.	O
</s>
<s>
Early	O
in	O
1972	O
,	O
researchers	O
from	O
Xerox	O
PARC	O
were	O
given	O
a	O
tour	O
of	O
the	O
PLATO	B-Operating_System
system	I-Operating_System
at	O
the	O
University	O
of	O
Illinois	O
.	O
</s>
<s>
At	O
this	O
time	O
,	O
they	O
were	O
shown	O
parts	O
of	O
the	O
system	O
,	O
such	O
as	O
the	O
Insert	O
Display/Show	O
Display	O
(	O
ID/SD	O
)	O
application	O
generator	O
for	O
pictures	O
on	O
PLATO	B-Operating_System
(	O
later	O
translated	O
into	O
a	O
graphics-draw	O
program	O
on	O
the	O
Xerox	B-Operating_System
Star	I-Operating_System
workstation	O
)	O
;	O
the	O
Charset	O
Editor	O
for	O
"	O
painting	O
"	O
new	O
characters	O
(	O
later	O
translated	O
into	O
a	O
"	O
Doodle	O
"	O
program	O
at	O
PARC	O
)	O
;	O
and	O
the	O
Term	O
Talk	O
and	O
Monitor	O
Mode	O
communications	O
programs	O
.	O
</s>
<s>
As	O
PLATO	B-Operating_System
IV	I-Operating_System
reached	O
production	O
quality	O
,	O
William	O
Norris	O
(	O
CDC	O
)	O
became	O
increasingly	O
interested	O
in	O
it	O
as	O
a	O
potential	O
product	O
.	O
</s>
<s>
PLATO	B-Operating_System
offered	O
a	O
solution	O
by	O
providing	O
higher	O
education	O
to	O
segments	O
of	O
the	O
population	O
that	O
would	O
otherwise	O
never	O
be	O
able	O
to	O
afford	O
a	O
university	O
education	O
.	O
</s>
<s>
In	O
1971	O
,	O
he	O
set	O
up	O
a	O
new	O
division	O
within	O
CDC	O
to	O
develop	O
PLATO	B-Operating_System
"	O
courseware	O
"	O
,	O
and	O
eventually	O
many	O
of	O
CDC	O
's	O
own	O
initial	O
training	O
and	O
technical	O
manuals	O
ran	O
on	O
it	O
.	O
</s>
<s>
In	O
1974	O
,	O
PLATO	B-Operating_System
was	O
running	O
on	O
in-house	O
machines	O
at	O
CDC	O
headquarters	O
in	O
Minneapolis	O
,	O
and	O
in	O
1976	O
,	O
they	O
purchased	O
the	O
commercial	O
rights	O
in	O
exchange	O
for	O
a	O
new	O
CDC	B-Device
Cyber	I-Device
machine	O
.	O
</s>
<s>
CDC	O
announced	O
the	O
acquisition	O
soon	O
after	O
,	O
claiming	O
that	O
by	O
1985	O
,	O
50%	O
of	O
the	O
company	O
's	O
income	O
would	O
be	O
related	O
to	O
PLATO	B-Operating_System
services	O
.	O
</s>
<s>
Through	O
the	O
1970s	O
,	O
CDC	O
tirelessly	O
promoted	O
PLATO	B-Operating_System
,	O
both	O
as	O
a	O
commercial	O
tool	O
and	O
one	O
for	O
re-training	O
unemployed	O
workers	O
in	O
new	O
fields	O
.	O
</s>
<s>
CDC	O
even	O
went	O
as	O
far	O
as	O
to	O
place	O
PLATO	B-Operating_System
terminals	I-Operating_System
in	O
some	O
shareholder	O
's	O
houses	O
,	O
to	O
demonstrate	O
the	O
concept	O
of	O
the	O
system	O
.	O
</s>
<s>
PLATO	B-Operating_System
was	O
,	O
therefore	O
,	O
a	O
failure	O
as	O
a	O
profitable	O
commercial	O
enterprise	O
,	O
although	O
it	O
did	O
find	O
some	O
use	O
in	O
large	O
companies	O
and	O
government	O
agencies	O
willing	O
to	O
invest	O
in	O
the	O
technology	O
.	O
</s>
<s>
An	O
attempt	O
to	O
mass-market	O
the	O
PLATO	B-Operating_System
system	I-Operating_System
was	O
introduced	O
in	O
1980	O
as	O
Micro-PLATO	O
,	O
which	O
ran	O
the	O
basic	O
TUTOR	B-Language
system	O
on	O
a	O
CDC	O
"	O
Viking-721	O
"	O
terminal	B-General_Concept
and	O
various	O
home	O
computers	O
.	O
</s>
<s>
Versions	O
were	O
built	O
for	O
the	O
TI-99/4A	B-Device
,	O
Atari	B-Device
8-bit	I-Device
family	I-Device
,	O
Zenith	B-Architecture
Z-100	I-Architecture
and	O
,	O
later	O
,	O
Radio	B-Device
Shack	I-Device
TRS-80	I-Device
and	O
IBM	B-Device
Personal	I-Device
Computer	I-Device
.	O
</s>
<s>
Micro-PLATO	O
could	O
be	O
used	O
stand-alone	O
for	O
normal	O
courses	O
,	O
or	O
could	O
connect	O
to	O
a	O
CDC	O
data	O
center	O
for	O
multiuser	O
programs	O
.	O
</s>
<s>
Norris	O
continued	O
to	O
praise	O
PLATO	B-Operating_System
,	O
announcing	O
that	O
it	O
would	O
be	O
only	O
a	O
few	O
years	O
before	O
it	O
represented	O
a	O
major	O
source	O
of	O
income	O
for	O
CDC	O
as	O
late	O
as	O
1984	O
.	O
</s>
<s>
In	O
1986	O
,	O
Norris	O
stepped	O
down	O
as	O
CEO	O
,	O
and	O
the	O
PLATO	B-Operating_System
service	O
was	O
slowly	O
killed	O
off	O
.	O
</s>
<s>
He	O
later	O
claimed	O
that	O
Micro-PLATO	O
was	O
one	O
of	O
the	O
reasons	O
PLATO	B-Operating_System
got	O
off-track	O
.	O
</s>
<s>
They	O
had	O
started	O
on	O
the	O
TI-99/4A	B-Device
,	O
but	O
then	O
Texas	O
Instruments	O
pulled	O
the	O
plug	O
and	O
they	O
moved	O
to	O
other	O
systems	O
like	O
the	O
Atari	O
,	O
who	O
soon	O
did	O
the	O
same	O
.	O
</s>
<s>
He	O
felt	O
that	O
it	O
was	O
a	O
waste	O
of	O
time	O
anyway	O
,	O
as	O
the	O
system	O
's	O
value	O
was	O
in	O
its	O
online	O
nature	O
,	O
which	O
Micro-PLATO	O
lacked	O
initially	O
.	O
</s>
<s>
Intel	B-General_Concept
8080	I-General_Concept
microprocessors	O
were	O
introduced	O
in	O
the	O
new	O
PLATO	B-Operating_System
V	I-Operating_System
terminals	O
.	O
</s>
<s>
It	O
was	O
a	O
way	O
to	O
augment	O
the	O
PLATO	B-Operating_System
courseware	O
with	O
rich	O
animation	O
and	O
other	O
sophisticated	O
capabilities	O
.	O
</s>
<s>
Although	O
PLATO	B-Operating_System
was	O
designed	O
for	O
computer-based	O
education	O
,	O
perhaps	O
its	O
most	O
enduring	O
legacy	O
is	O
its	O
place	O
in	O
the	O
origins	O
of	O
online	O
community	O
.	O
</s>
<s>
This	O
was	O
made	O
possible	O
by	O
PLATO	B-Operating_System
's	O
groundbreaking	O
communication	O
and	O
interface	O
capabilities	O
,	O
features	O
whose	O
significance	O
is	O
only	O
lately	O
being	O
recognized	O
by	O
computer	O
historians	O
.	O
</s>
<s>
PLATO	B-Operating_System
Notes	O
,	O
created	O
by	O
David	O
R	O
.	O
Woolley	O
in	O
1973	O
,	O
was	O
among	O
the	O
world	O
's	O
first	O
online	B-Application
message	I-Application
boards	I-Application
,	O
and	O
years	O
later	O
became	O
the	O
direct	O
progenitor	O
of	O
Lotus	B-Operating_System
Notes	I-Operating_System
.	O
</s>
<s>
PLATO	B-Operating_System
's	O
plasma	O
panels	O
were	O
well	O
suited	O
to	O
games	O
,	O
although	O
its	O
I/O	O
bandwidth	O
(	O
180	O
characters	O
per	O
second	O
or	O
60	O
graphic	O
lines	O
per	O
second	O
)	O
was	O
relatively	O
slow	O
.	O
</s>
<s>
By	O
virtue	O
of	O
1500	O
shared	O
60-bit	O
variables	O
per	O
game	O
(	O
initially	O
)	O
,	O
it	O
was	O
possible	O
to	O
implement	O
online	B-Application
games	I-Application
.	O
</s>
<s>
In	O
much	O
the	O
same	O
way	O
that	O
the	O
PLATO	B-Operating_System
hardware	O
and	O
development	O
platform	O
inspired	O
advances	O
elsewhere	O
(	O
such	O
as	O
at	O
Xerox	O
PARC	O
and	O
MIT	O
)	O
,	O
many	O
popular	O
commercial	O
and	O
Internet	B-Application
games	I-Application
ultimately	O
derived	O
their	O
inspiration	O
from	O
PLATO	B-Operating_System
's	O
early	O
games	O
.	O
</s>
<s>
As	O
one	O
example	O
,	O
Castle	B-Application
Wolfenstein	I-Application
by	O
PLATO	B-Operating_System
alum	O
Silas	B-Application
Warner	I-Application
was	O
inspired	O
by	O
PLATO	B-Operating_System
's	O
dungeon	O
games	O
(	O
see	O
below	O
)	O
,	O
in	O
turn	O
inspiring	O
Doom	B-Application
and	O
Quake	B-Application
.	O
</s>
<s>
Thousands	O
of	O
multiplayer	B-Application
online	I-Application
games	I-Application
were	O
developed	O
on	O
PLATO	B-Operating_System
from	O
around	O
1970	O
through	O
the	O
1980s	O
,	O
with	O
the	O
following	O
notable	O
examples	O
:	O
</s>
<s>
Daleske	O
's	O
Empire	B-Application
a	O
top-view	O
multiplayer	O
space	O
game	O
based	O
on	O
Star	B-Operating_System
Trek	I-Operating_System
.	O
</s>
<s>
Either	O
Empire	B-Application
or	O
Colley	O
's	O
Maze	B-Application
War	I-Application
is	O
the	O
first	O
networked	O
multiplayer	O
action	O
game	O
.	O
</s>
<s>
It	O
was	O
ported	O
to	O
Trek82	O
,	O
Trek83	O
,	O
ROBOTREK	O
,	O
Xtrek	O
,	O
and	O
Netrek	O
,	O
and	O
also	O
adapted	O
(	O
without	O
permission	O
)	O
for	O
the	O
Apple	O
II	O
computer	O
by	O
fellow	O
PLATO	B-Operating_System
alum	O
Robert	O
Woodhead	O
(	O
of	O
Wizardry	B-Application
fame	O
)	O
,	O
as	O
a	O
game	O
called	O
Galactic	O
Attack	O
.	O
</s>
<s>
The	O
original	O
Freecell	B-Application
by	O
Alfille	O
(	O
from	O
Baker	O
's	O
concept	O
)	O
.	O
</s>
<s>
Fortner	O
's	O
Airfight	B-Application
,	O
probably	O
the	O
direct	O
inspiration	O
for	O
(	O
PLATO	B-Operating_System
alum	O
)	O
Bruce	O
Artwick	O
's	O
Microsoft	B-Operating_System
Flight	I-Operating_System
Simulator	I-Operating_System
.	O
</s>
<s>
Haefeli	O
and	O
Bridwell	O
's	O
Panther	B-Application
(	O
a	O
vector	O
graphics-based	O
tankwar	O
game	O
,	O
anticipating	O
Atari	O
's	O
Battlezone	B-Application
)	O
.	O
</s>
<s>
Countless	O
games	O
inspired	O
by	O
the	O
role-playing	O
game	O
Dungeons	O
&	O
Dragons	O
,	O
including	O
the	O
original	O
Rutherford/Whisenhunt	O
and	O
Wood	O
dnd	B-Application
(	O
later	O
ported	O
to	O
the	O
PDP-10/11	O
by	O
Lawrence	O
,	O
who	O
earlier	O
had	O
visited	O
PLATO	B-Operating_System
)	O
.	O
</s>
<s>
and	O
is	O
believed	O
to	O
be	O
the	O
first	O
dungeon	O
crawl	O
game	O
and	O
was	O
followed	O
by	O
:	O
Moria	B-Application
,	O
Rogue	B-Protocol
,	O
Dry	O
Gulch	O
(	O
a	O
western-style	O
variation	O
)	O
,	O
and	O
Bugs-n-Drugs	O
(	O
a	O
medical	O
variation	O
)	O
—	O
all	O
presaging	O
MUDs	B-Application
(	O
Multi-User	B-Application
Domains	I-Application
)	O
and	O
MOOs	B-Application
(	O
MUDs	B-Application
,	O
Object	O
Oriented	O
)	O
as	O
well	O
as	O
popular	O
first-person	O
shooters	O
like	O
Doom	B-Application
and	O
Quake	B-Application
,	O
and	O
MMORPGs	B-Protocol
(	O
Massively	B-Protocol
multiplayer	I-Protocol
online	I-Protocol
role-playing	I-Protocol
game	I-Protocol
)	O
like	O
EverQuest	B-Protocol
and	O
World	B-Protocol
of	I-Protocol
Warcraft	I-Protocol
.	O
</s>
<s>
Avatar	B-Application
,	O
PLATO	B-Operating_System
's	O
most	O
popular	O
game	O
,	O
is	O
one	O
of	O
the	O
world	O
's	O
first	O
MUDs	B-Application
and	O
has	O
over	O
1	O
million	O
hours	O
of	O
use	O
..	O
</s>
<s>
The	O
games	O
Doom	B-Application
and	O
Quake	B-Application
can	O
trace	O
part	O
of	O
their	O
lineage	O
back	O
to	O
PLATO	B-Operating_System
programmer	O
Silas	B-Application
Warner	I-Application
.	O
</s>
<s>
PLATO	B-Operating_System
's	O
communication	O
tools	O
and	O
games	O
formed	O
the	O
basis	O
for	O
an	O
online	O
community	O
of	O
thousands	O
of	O
PLATO	B-Operating_System
users	O
,	O
which	O
lasted	O
for	O
well	O
over	O
twenty	O
years	O
.	O
</s>
<s>
PLATO	B-Operating_System
's	O
games	O
became	O
so	O
popular	O
that	O
a	O
program	O
called	O
"	O
The	O
Enforcer	O
"	O
was	O
written	O
to	O
run	O
as	O
a	O
background	O
process	O
to	O
regulate	O
or	O
disable	O
game	O
play	O
at	O
most	O
sites	O
and	O
times	O
–	O
a	O
precursor	O
to	O
parental-style	O
control	O
systems	O
that	O
regulate	O
access	O
based	O
on	O
content	O
rather	O
than	O
security	O
considerations	O
.	O
</s>
<s>
In	O
September	O
2006	O
the	O
Federal	O
Aviation	O
Administration	O
retired	O
its	O
PLATO	B-Operating_System
system	I-Operating_System
,	O
the	O
last	O
system	O
that	O
ran	O
the	O
PLATO	B-Operating_System
software	O
system	O
on	O
a	O
CDC	B-Device
Cyber	I-Device
mainframe	B-Architecture
,	O
from	O
active	O
duty	O
.	O
</s>
<s>
Existing	O
PLATO-like	O
systems	O
now	O
include	O
NovaNET	O
and	O
Cyber1.org	O
.	O
</s>
<s>
By	O
early	O
1976	O
,	O
the	O
original	O
PLATO	B-Operating_System
IV	I-Operating_System
system	O
had	O
950	O
terminals	O
giving	O
access	O
to	O
more	O
than	O
3500	O
contact	O
hours	O
of	O
courseware	O
,	O
and	O
additional	O
systems	O
were	O
in	O
operation	O
at	O
CDC	O
and	O
Florida	O
State	O
University	O
.	O
</s>
<s>
PLATO	B-Operating_System
courseware	O
covers	O
a	O
full	O
range	O
of	O
high-school	O
and	O
college	O
courses	O
,	O
as	O
well	O
as	O
topics	O
such	O
as	O
reading	O
skills	O
,	O
family	O
planning	O
,	O
Lamaze	O
training	O
and	O
home	O
budgeting	O
.	O
</s>
<s>
However	O
the	O
most	O
popular	O
"	O
courseware	O
"	O
remained	O
their	O
multi-user	O
games	O
and	O
role-playing	O
video	O
games	O
such	O
as	O
dnd	B-Application
,	O
although	O
it	O
appears	O
CDC	O
was	O
uninterested	O
in	O
this	O
market	O
.	O
</s>
<s>
As	O
the	O
value	O
of	O
a	O
CDC-based	O
solution	O
disappeared	O
in	O
the	O
1980s	O
,	O
interested	O
educators	O
ported	O
the	O
engine	O
first	O
to	O
the	O
IBM	B-Device
PC	I-Device
,	O
and	O
later	O
to	O
web-based	O
systems	O
.	O
</s>
<s>
In	O
preparation	O
for	O
a	O
PLATO	B-Operating_System
demo	O
in	O
Tehran	O
,	O
that	O
Bruce	O
Sherwood	O
would	O
participate	O
in	O
,	O
Sherwood	O
worked	O
with	O
Don	O
Lee	O
to	O
implement	O
support	O
for	O
leftward	O
writing	O
,	O
including	O
Persian	O
(	O
Farsi	O
)	O
,	O
which	O
uses	O
the	O
Arabic	O
script	O
.	O
</s>
<s>
The	O
PLATO	B-Operating_System
hardware	O
and	O
software	O
supported	O
the	O
design	O
and	O
use	O
of	O
one	O
's	O
own	O
8-by-16	O
characters	O
,	O
so	O
most	O
languages	O
could	O
be	O
displayed	O
on	O
the	O
graphics	O
screen	O
(	O
including	O
those	O
written	O
right-to-left	O
)	O
.	O
</s>
<s>
A	O
PLATO-compatible	O
music	O
language	O
known	O
as	O
OPAL	O
(	O
Octave-Pitch-Accent-Length	O
)	O
was	O
developed	O
for	O
these	O
synthesizers	O
,	O
as	O
well	O
as	O
a	O
compiler	O
for	O
the	O
language	O
,	O
two	O
music	O
text	O
editors	O
,	O
a	O
filing	O
system	O
for	O
music	O
binaries	O
,	O
programs	O
to	O
play	O
the	O
music	O
binaries	O
in	O
real	O
time	O
,	O
and	O
print	O
musical	O
scores	O
,	O
and	O
many	O
debugging	O
and	O
compositional	O
aids	O
.	O
</s>
<s>
Gooch	O
's	O
peripherals	O
were	O
heavily	O
used	O
for	O
music	O
education	O
courseware	O
as	O
created	O
,	O
for	O
example	O
,	O
by	O
the	O
University	O
of	O
Illinois	O
School	O
of	O
Music	O
PLATO	B-Operating_System
Project	O
.	O
</s>
<s>
From	O
1970	O
to	O
1994	O
,	O
the	O
University	O
of	O
Illinois	O
(	O
U	O
of	O
I	O
)	O
School	O
of	O
Music	O
explored	O
the	O
use	O
of	O
the	O
Computer-based	B-Operating_System
Education	I-Operating_System
Research	I-Operating_System
Laboratory	I-Operating_System
(	O
CERL	O
)	O
PLATO	B-Operating_System
computer	I-Operating_System
system	O
to	O
deliver	O
online	O
instruction	O
in	O
music	O
.	O
</s>
<s>
Led	O
by	O
G	O
.	O
David	O
Peters	O
,	O
music	O
faculty	O
and	O
students	O
worked	O
with	O
PLATO	B-Operating_System
’s	O
technical	O
capabilities	O
to	O
produce	O
music-related	O
instructional	O
materials	O
and	O
experimented	O
with	O
their	O
use	O
in	O
the	O
music	O
curriculum	O
.	O
</s>
<s>
Peters	O
began	O
his	O
work	O
on	O
PLATO	B-Operating_System
III	I-Operating_System
.	O
</s>
<s>
By	O
1972	O
,	O
the	O
PLATO	B-Operating_System
IV	I-Operating_System
system	O
made	O
it	O
technically	O
possible	O
to	O
introduce	O
multimedia	O
pedagogies	O
that	O
were	O
not	O
available	O
in	O
the	O
marketplace	O
until	O
years	O
later	O
.	O
</s>
<s>
In	O
1988	O
,	O
the	O
project	O
broadened	O
its	O
focus	O
beyond	O
PLATO	B-Operating_System
to	O
accommodate	O
the	O
increasing	O
availability	O
and	O
use	O
of	O
microcomputers	B-Architecture
.	O
</s>
<s>
Work	O
in	O
the	O
School	O
of	O
Music	O
continued	O
on	O
other	O
platforms	O
after	O
the	O
CERL	O
PLATO	B-Operating_System
system	I-Operating_System
shutdown	O
in	O
1994	O
.	O
</s>
<s>
In	O
1969	O
,	O
G	O
.	O
David	O
Peters	O
began	O
researching	O
the	O
feasibility	O
of	O
using	O
PLATO	B-Operating_System
to	O
teach	O
trumpet	O
students	O
to	O
play	O
with	O
increased	O
pitch	O
and	O
rhythmic	O
precision	O
.	O
</s>
<s>
He	O
created	O
an	O
interface	O
for	O
the	O
PLATO	B-Operating_System
III	I-Operating_System
terminal	B-General_Concept
.	O
</s>
<s>
By	O
1970	O
,	O
a	O
random	O
access	O
audio	O
device	O
was	O
available	O
for	O
use	O
with	O
PLATO	B-Operating_System
III	I-Operating_System
.	O
</s>
<s>
Placek	O
used	O
the	O
random	O
access	O
audio	O
device	O
attached	O
to	O
a	O
PLATO	B-Operating_System
III	I-Operating_System
terminal	B-General_Concept
for	O
which	O
he	O
developed	O
music	O
notation	O
fonts	O
and	O
graphics	O
.	O
</s>
<s>
This	O
was	O
the	O
first	O
known	O
application	O
of	O
the	O
PLATO	B-Operating_System
random-access	O
audio	O
device	O
to	O
computer-based	O
music	O
instruction	O
.	O
</s>
<s>
Of	O
particular	O
value	O
was	O
PLATO	B-Operating_System
’s	O
immediate	O
feedback	O
.	O
</s>
<s>
These	O
PLATO	B-Operating_System
IV	I-Operating_System
terminal	B-General_Concept
included	O
many	O
new	O
devices	O
and	O
yielded	O
two	O
notable	O
music	O
projects	O
:	O
</s>
<s>
In	O
1978	O
,	O
William	O
H	O
.	O
Sanders	O
adapted	O
Froseth	O
’s	O
program	O
for	O
delivery	O
using	O
the	O
PLATO	B-Operating_System
IV	I-Operating_System
system	O
.	O
</s>
<s>
Sanders	O
transferred	O
the	O
slides	O
to	O
microfiche	O
for	O
rear-projection	O
through	O
the	O
PLATO	B-Operating_System
IV	I-Operating_System
terminal	B-General_Concept
’s	O
plasma	O
display	O
.	O
</s>
<s>
Sanders	O
and	O
Froseth	O
subsequently	O
conducted	O
a	O
study	O
to	O
compare	O
traditional	O
classroom	O
delivery	O
of	O
the	O
program	O
to	O
delivery	O
using	O
PLATO	B-Operating_System
.	O
</s>
<s>
Random-access	O
audio	O
devices	O
interfaced	O
to	O
PLATO	B-Operating_System
IV	I-Operating_System
terminals	O
were	O
also	O
available	O
.	O
</s>
<s>
By	O
1988	O
,	O
with	O
the	O
spread	O
of	O
micro-computers	B-Architecture
and	O
their	O
peripherals	O
,	O
the	O
University	O
of	O
Illinois	O
School	O
of	O
Music	O
PLATO	B-Operating_System
Project	O
was	O
renamed	O
The	O
Illinois	O
Technology-based	O
Music	O
Project	O
.	O
</s>
<s>
Educators	O
and	O
students	O
used	O
the	O
PLATO	B-Operating_System
System	I-Operating_System
for	O
music	O
instruction	O
at	O
other	O
educational	O
institutions	O
including	O
Indiana	O
University	O
,	O
Florida	O
State	O
University	O
,	O
and	O
the	O
University	O
of	O
Delaware	O
.	O
</s>
<s>
Many	O
alumni	O
of	O
the	O
University	O
of	O
Illinois	O
School	O
of	O
Music	O
PLATO	B-Operating_System
Project	O
gained	O
early	O
hands-on	O
experience	O
in	O
computing	O
and	O
media	O
technologies	O
and	O
moved	O
into	O
influential	O
positions	O
in	O
both	O
education	O
and	O
the	O
private	O
sector	O
.	O
</s>
<s>
The	O
goal	O
of	O
this	O
system	O
was	O
to	O
provide	O
tools	O
for	O
music	O
educators	O
to	O
use	O
in	O
the	O
development	O
of	O
instructional	O
materials	O
,	O
which	O
might	O
possibly	O
include	O
music	O
dictation	O
drills	O
,	O
automatically	O
graded	O
keyboard	B-Device
performances	O
,	O
envelope	O
and	O
timbre	O
ear-training	O
,	O
interactive	O
examples	O
or	O
labs	O
in	O
musical	O
acoustics	O
,	O
and	O
composition	O
and	O
theory	O
exercises	O
with	O
immediate	O
feedback	O
.	O
</s>
<s>
Another	O
peripheral	O
was	O
the	O
Votrax	B-Application
speech	O
synthesizer	O
,	O
and	O
a	O
"	O
say	O
"	O
instruction	O
(	O
with	O
"	O
saylang	O
"	O
instruction	O
to	O
choose	O
the	O
language	O
)	O
was	O
added	O
to	O
the	O
Tutor	B-Language
programming	I-Language
language	I-Language
to	O
support	O
text-to-speech	O
synthesis	O
using	O
the	O
Votrax	B-Application
.	O
</s>
<s>
One	O
of	O
CDC	O
's	O
greatest	O
commercial	O
successes	O
with	O
PLATO	B-Operating_System
was	O
an	O
online	B-Application
testing	I-Application
system	O
developed	O
for	O
National	O
Association	O
of	O
Securities	O
Dealers	O
(	O
now	O
the	O
Financial	O
Industry	O
Regulatory	O
Authority	O
)	O
,	O
a	O
private-sector	O
regulator	O
of	O
the	O
US	O
securities	O
markets	O
.	O
</s>
<s>
During	O
the	O
1970s	O
Michael	O
Stein	O
,	O
E	O
.	O
Clarke	O
Porter	O
and	O
PLATO	B-Operating_System
veteran	O
Jim	O
Ghesquiere	O
,	O
in	O
cooperation	O
with	O
NASD	O
executive	O
Frank	O
McAuliffe	O
,	O
developed	O
the	O
first	O
"	O
on-demand	O
"	O
proctored	O
commercial	O
testing	O
service	O
.	O
</s>
<s>
Applying	O
many	O
of	O
the	O
PLATO	B-Operating_System
concepts	O
used	O
in	O
the	O
late	O
1970s	O
,	O
E	O
.	O
Clarke	O
Porter	O
led	O
the	O
Drake	O
Training	O
and	O
Technologies	O
testing	O
business	O
(	O
today	O
Thomson	O
Prometric	O
)	O
in	O
partnership	O
with	O
Novell	O
,	O
Inc	O
.	O
away	O
from	O
the	O
mainframe	B-Architecture
model	O
to	O
a	O
LAN-based	O
client	O
server	O
architecture	O
and	O
changed	O
the	O
business	O
model	O
to	O
deploy	O
proctored	O
testing	O
at	O
thousands	O
of	O
independent	O
training	O
organizations	O
on	O
a	O
global	O
scale	O
.	O
</s>
<s>
With	O
the	O
advent	O
of	O
a	O
pervasive	O
global	O
network	O
of	O
testing	O
centers	O
and	O
IT	O
certification	O
programs	O
sponsored	O
by	O
,	O
among	O
others	O
,	O
Novell	O
and	O
Microsoft	O
,	O
the	O
online	B-Application
testing	I-Application
business	O
exploded	O
.	O
</s>
<s>
Pearson	O
VUE	O
was	O
founded	O
by	O
PLATO/Prometric	O
veterans	O
E	O
.	O
Clarke	O
Porter	O
,	O
Steve	O
Nordberg	O
and	O
Kirk	O
Lundeen	O
in	O
1994	O
to	O
further	O
expand	O
the	O
global	O
testing	O
infrastructure	O
.	O
</s>
<s>
The	O
computer-based	B-Application
testing	I-Application
industry	O
has	O
continued	O
to	O
grow	O
,	O
adding	O
professional	O
licensure	O
and	O
educational	O
testing	O
as	O
important	O
business	O
segments	O
.	O
</s>
<s>
A	O
number	O
of	O
smaller	O
testing-related	O
companies	O
also	O
evolved	O
from	O
the	O
PLATO	B-Operating_System
system	I-Operating_System
.	O
</s>
<s>
In	O
the	O
early	O
1970s	O
,	O
James	O
Schuyler	O
developed	O
a	O
system	O
at	O
Northwestern	O
University	O
called	O
HYPERTUTOR	O
as	O
part	O
of	O
Northwestern	O
's	O
MULTI-TUTOR	O
computer	O
assisted	O
instruction	O
system	O
.	O
</s>
<s>
This	O
ran	O
on	O
several	O
CDC	O
mainframes	B-Architecture
at	O
various	O
sites	O
.	O
</s>
<s>
Between	O
1973	O
and	O
1980	O
,	O
a	O
group	O
under	O
the	O
direction	O
of	O
Thomas	O
T	O
.	O
Chen	O
at	O
the	O
Medical	O
Computing	O
Laboratory	O
of	O
the	O
School	O
of	O
Basic	O
Medical	O
Sciences	O
at	O
the	O
University	O
of	O
Illinois	O
at	O
Urbana	O
Champaign	O
ported	O
PLATO	B-Operating_System
's	O
TUTOR	B-Language
programming	I-Language
language	I-Language
to	O
the	O
MODCOMP	O
IV	O
minicomputer	O
.	O
</s>
<s>
This	O
was	O
the	O
first	O
port	O
of	O
TUTOR	B-Language
to	O
a	O
minicomputer	O
and	O
was	O
largely	O
operational	O
by	O
1976	O
.	O
</s>
<s>
GIST	O
eventually	O
merged	O
with	O
the	O
Government	O
Group	O
of	O
Adayana	O
Inc	O
.	O
Vincent	O
Wu	O
went	O
on	O
to	O
develop	O
the	O
Atari	O
PLATO	B-Operating_System
cartridge	O
.	O
</s>
<s>
CDC	O
eventually	O
sold	O
the	O
"	O
PLATO	B-Operating_System
"	O
trademark	O
and	O
some	O
courseware	O
marketing	O
segment	O
rights	O
to	O
the	O
newly	O
formed	O
The	O
Roach	O
Organization	O
(	O
TRO	O
)	O
in	O
1989	O
.	O
</s>
<s>
In	O
2000	O
TRO	O
changed	O
their	O
name	O
to	O
PLATO	B-Operating_System
Learning	O
and	O
continue	O
to	O
sell	O
and	O
service	O
PLATO	B-Operating_System
courseware	O
running	O
on	O
PCs	O
.	O
</s>
<s>
In	O
late	O
2012	O
,	O
PLATO	B-Operating_System
Learning	O
brought	O
its	O
online	O
learning	O
solutions	O
to	O
market	O
under	O
the	O
name	O
Edmentum	O
.	O
</s>
<s>
The	O
University	O
of	O
Illinois	O
also	O
continued	O
development	O
of	O
PLATO	B-Operating_System
,	O
eventually	O
setting	O
up	O
a	O
commercial	O
on-line	O
service	O
called	O
NovaNET	O
in	O
partnership	O
with	O
University	O
Communications	O
,	O
Inc	O
.	O
CERL	O
was	O
closed	O
in	O
1994	O
,	O
with	O
the	O
maintenance	O
of	O
the	O
PLATO	B-Operating_System
code	O
passing	O
to	O
UCI	O
.	O
</s>
<s>
During	O
the	O
period	O
when	O
CDC	O
was	O
marketing	O
PLATO	B-Operating_System
,	O
the	O
system	O
began	O
to	O
be	O
used	O
internationally	O
.	O
</s>
<s>
South	O
Africa	O
was	O
one	O
of	O
the	O
biggest	O
users	O
of	O
PLATO	B-Operating_System
in	O
the	O
early	O
1980s	O
.	O
</s>
<s>
Eskom	O
,	O
the	O
South	O
African	O
electrical	O
power	O
company	O
,	O
had	O
a	O
large	O
CDC	O
mainframe	B-Architecture
at	O
Megawatt	O
Park	O
in	O
the	O
northwest	O
suburbs	O
of	O
Johannesburg	O
.	O
</s>
<s>
Mainly	O
this	O
computer	O
was	O
used	O
for	O
management	O
and	O
data	O
processing	O
tasks	O
related	O
to	O
power	O
generation	O
and	O
distribution	O
,	O
but	O
it	O
also	O
ran	O
the	O
PLATO	B-Operating_System
software	O
.	O
</s>
<s>
The	O
largest	O
PLATO	B-Operating_System
installation	O
in	O
South	O
Africa	O
during	O
the	O
early	O
1980s	O
was	O
at	O
the	O
University	O
of	O
the	O
Western	O
Cape	O
,	O
which	O
served	O
the	O
"	O
native	O
"	O
population	O
,	O
and	O
at	O
one	O
time	O
had	O
hundreds	O
of	O
PLATO	B-Operating_System
IV	I-Operating_System
terminals	O
all	O
connected	O
by	O
leased	O
data	O
lines	O
back	O
to	O
Johannesburg	O
.	O
</s>
<s>
This	O
was	O
perhaps	O
the	O
most	O
unusual	O
PLATO	B-Operating_System
installation	O
anywhere	O
.	O
</s>
<s>
So	O
an	O
air-conditioned	O
,	O
carpeted	O
room	O
with	O
16	O
computer	B-General_Concept
terminals	I-General_Concept
was	O
a	O
stark	O
contrast	O
to	O
the	O
rest	O
of	O
the	O
college	O
.	O
</s>
<s>
At	O
times	O
the	O
only	O
way	O
a	O
person	O
could	O
communicate	O
with	O
the	O
outside	O
world	O
was	O
through	O
PLATO	B-Operating_System
term-talk	O
.	O
</s>
<s>
For	O
many	O
of	O
the	O
Madadeni	O
students	O
,	O
most	O
of	O
whom	O
came	O
from	O
very	O
rural	O
areas	O
,	O
the	O
PLATO	B-Operating_System
terminal	B-General_Concept
was	O
the	O
first	O
time	O
they	O
encountered	O
any	O
kind	O
of	O
electronic	O
technology	O
.	O
</s>
<s>
There	O
initially	O
was	O
skepticism	O
that	O
these	O
technologically	O
illiterate	O
students	O
could	O
effectively	O
use	O
PLATO	B-Operating_System
,	O
but	O
those	O
concerns	O
were	O
not	O
borne	O
out	O
.	O
</s>
<s>
A	O
few	O
students	O
even	O
used	O
on-line	O
resources	O
to	O
learn	O
TUTOR	B-Language
,	O
the	O
PLATO	B-Operating_System
programming	O
language	O
,	O
and	O
a	O
few	O
wrote	O
lessons	O
on	O
the	O
system	O
in	O
the	O
Zulu	O
language	O
.	O
</s>
<s>
PLATO	B-Operating_System
was	O
also	O
used	O
fairly	O
extensively	O
in	O
South	O
Africa	O
for	O
industrial	O
training	O
.	O
</s>
<s>
Eskom	O
successfully	O
used	O
PLM	O
(	O
PLATO	B-Operating_System
learning	O
management	O
)	O
and	O
simulations	O
to	O
train	O
power	O
plant	O
operators	O
,	O
South	O
African	O
Airways	O
(	O
SAA	O
)	O
used	O
PLATO	B-Operating_System
simulations	O
for	O
cabin	O
attendant	O
training	O
,	O
and	O
there	O
were	O
a	O
number	O
of	O
other	O
large	O
companies	O
as	O
well	O
that	O
were	O
exploring	O
the	O
use	O
of	O
PLATO	B-Operating_System
.	O
</s>
<s>
The	O
South	O
African	O
subsidiary	O
of	O
CDC	O
invested	O
heavily	O
in	O
the	O
development	O
of	O
an	O
entire	O
secondary	O
school	O
curriculum	O
(	O
SASSC	O
)	O
on	O
PLATO	B-Operating_System
,	O
but	O
unfortunately	O
as	O
the	O
curriculum	O
was	O
nearing	O
the	O
final	O
stages	O
of	O
completion	O
,	O
CDC	O
began	O
to	O
falter	O
in	O
South	O
Africa	O
—	O
partly	O
because	O
of	O
financial	O
problems	O
back	O
home	O
,	O
partly	O
because	O
of	O
growing	O
opposition	O
in	O
the	O
United	O
States	O
to	O
doing	O
business	O
in	O
South	O
Africa	O
,	O
and	O
partly	O
due	O
to	O
the	O
rapidly	O
evolving	O
microcomputer	B-Architecture
,	O
a	O
paradigm	O
shift	O
that	O
CDC	O
failed	O
to	O
recognize	O
.	O
</s>
<s>
In	O
August	O
2004	O
,	O
a	O
version	O
of	O
PLATO	B-Operating_System
corresponding	O
to	O
the	O
final	O
release	O
from	O
CDC	O
was	O
resurrected	O
online	O
.	O
</s>
<s>
This	O
version	O
of	O
PLATO	B-Operating_System
runs	O
on	O
a	O
free	B-License
and	I-License
open-source	I-License
software	I-License
emulation	B-Application
of	O
the	O
original	O
CDC	O
hardware	O
called	O
Desktop	O
Cyber	O
.	O
</s>
<s>
Many	O
of	O
the	O
students	O
who	O
used	O
PLATO	B-Operating_System
in	O
the	O
1970s	O
and	O
1980s	O
felt	O
a	O
special	O
social	O
bond	O
with	O
the	O
community	O
of	O
users	O
who	O
came	O
together	O
using	O
the	O
powerful	O
communications	O
tools	O
(	O
talk	O
programs	O
,	O
records	O
systems	O
and	O
notesfiles	O
)	O
on	O
PLATO	B-Operating_System
.	O
</s>
<s>
The	O
PLATO	B-Operating_System
software	O
used	O
on	O
Cyber1	O
is	O
the	O
final	O
release	O
(	O
99A	O
)	O
of	O
CYBIS	O
,	O
by	O
permission	O
of	O
VCampus	O
.	O
</s>
<s>
The	O
underlying	O
operating	O
system	O
is	O
NOS	O
2.8.7	O
,	O
the	O
final	O
release	O
of	O
the	O
NOS	O
operating	O
system	O
,	O
by	O
permission	O
of	O
Syntegra	O
(	O
now	O
British	O
Telecom	O
 [ BT ] 	O
)	O
,	O
which	O
had	O
acquired	O
the	O
remainder	O
of	O
CDC	O
's	O
mainframe	B-Architecture
business	O
.	O
</s>
<s>
Cyber1	O
runs	O
this	O
software	O
on	O
the	O
Desktop	O
Cyber	O
emulator	B-Application
.	O
</s>
<s>
Desktop	O
Cyber	O
accurately	O
emulates	B-Application
in	O
software	O
a	O
range	O
of	O
CDC	B-Device
Cyber	I-Device
mainframe	B-Architecture
models	O
and	O
many	O
peripherals	O
.	O
</s>
<s>
Cyber1	O
offers	O
free	O
access	O
to	O
the	O
system	O
,	O
which	O
contains	O
over	O
16,000	O
of	O
the	O
original	O
lessons	O
,	O
in	O
an	O
attempt	O
to	O
preserve	O
the	O
original	O
PLATO	B-Operating_System
communities	O
that	O
grew	O
up	O
at	O
CERL	O
and	O
on	O
CDC	O
systems	O
in	O
the	O
1980s	O
.	O
</s>
<s>
The	O
load	O
average	O
of	O
this	O
resurrected	O
system	O
is	O
about	O
10	O
–	O
15	O
users	O
,	O
sending	O
personal	O
and	O
notesfile	O
notes	O
,	O
and	O
playing	O
inter-terminal	O
games	O
such	O
as	O
Avatar	B-Application
and	O
Empire	B-Application
(	O
a	O
Star	O
Trek-like	O
game	O
)	O
,	O
which	O
had	O
both	O
accumulated	O
more	O
than	O
1.0	O
million	O
contact	O
hours	O
on	O
the	O
original	O
PLATO	B-Operating_System
system	I-Operating_System
at	O
UIUC	O
.	O
</s>
