<s>
THEOS	B-Device
,	O
which	O
translates	O
from	O
Greek	O
as	O
"	O
God	O
"	O
,	O
is	O
an	O
operating	B-General_Concept
system	I-General_Concept
which	O
started	O
out	O
as	O
OASIS	O
,	O
a	O
microcomputer	B-Architecture
operating	B-General_Concept
system	I-General_Concept
for	O
small	O
computers	O
that	O
use	O
the	O
Z80	B-General_Concept
processor	O
.	O
</s>
<s>
When	O
the	O
operating	B-General_Concept
system	I-General_Concept
was	O
launched	O
for	O
the	O
IBM	B-Operating_System
Personal	I-Operating_System
Computer/AT	I-Operating_System
in	O
1982	O
,	O
the	O
decision	O
was	O
taken	O
to	O
change	O
the	O
name	O
from	O
OASIS	O
to	O
THEOS	B-Device
,	O
short	O
for	O
THE	O
Operating	B-General_Concept
System	I-General_Concept
.	O
</s>
<s>
The	O
OASIS	O
operating	B-General_Concept
system	I-General_Concept
was	O
originally	O
developed	O
and	O
distributed	O
in	O
1977	O
by	O
Phase	O
One	O
Systems	O
of	O
Oakland	O
,	O
California	O
(	O
President	O
Howard	O
Sidorsky	O
)	O
.	O
</s>
<s>
OASIS	O
was	O
developed	O
for	O
the	O
Z80	B-General_Concept
processor	O
and	O
was	O
the	O
first	O
multi-user	O
operating	B-General_Concept
system	I-General_Concept
for	O
8-bit	O
microprocessor	O
based	O
computers	O
(	O
Z-80	B-General_Concept
from	O
Zilog	O
)	O
.	O
</s>
<s>
OASIS	O
consisted	O
of	O
a	O
multi-user	O
operating	B-General_Concept
system	I-General_Concept
,	O
a	O
powerful	O
Business	O
Basic/Interpreter	O
,	O
C	B-Language
compiler	O
and	O
a	O
powerful	O
text	O
editor	O
.	O
</s>
<s>
The	O
market	O
asked	O
for	O
16-bit	B-Device
systems	O
but	O
there	O
was	O
no	O
real	O
16-bit	B-Device
multi-user	O
OS	O
for	O
16-bit	B-Device
systems	O
.	O
</s>
<s>
The	O
court	O
case	O
took	O
two	O
years	O
and	O
finally	O
the	O
ruling	O
was	O
that	O
Timothy	O
Williams	O
was	O
allowed	O
to	O
develop	O
the	O
16-bit	B-Device
version	O
of	O
OASIS	O
but	O
he	O
was	O
not	O
allowed	O
to	O
use	O
the	O
OASIS	O
name	O
anymore	O
.	O
</s>
<s>
He	O
said	O
Timothy	O
Williams	O
developed	O
the	O
OASIS	O
operating	B-General_Concept
system	I-General_Concept
and	O
contracted	O
with	O
Phase	O
One	O
Systems	O
to	O
market	O
and	O
sell	O
the	O
product	O
.	O
</s>
<s>
Development	O
of	O
the	O
16-bit	B-Device
product	O
was	O
underway	O
,	O
but	O
the	O
product	O
was	O
prematurely	O
announced	O
by	O
POS	O
.	O
</s>
<s>
(	O
OASIS	O
8-bit	O
was	O
quite	O
well	O
optimised	O
by	O
that	O
point	O
,	O
with	O
many	O
parts	O
hand-coded	O
in	O
Z80	B-General_Concept
assembler	O
,	O
but	O
that	O
meant	O
then-new	O
16-bit	B-Device
systems	O
performed	O
nowhere	O
near	O
as	O
well	O
as	O
their	O
8-bit	O
counterparts	O
)	O
.	O
</s>
<s>
This	O
situation	O
led	O
to	O
Williams	O
becoming	O
dissatisfied	O
with	O
the	O
Phase	O
One	O
company	O
at	O
the	O
time	O
,	O
and	O
forming	O
his	O
own	O
company	O
to	O
market	O
and	O
support	O
the	O
16-bit	B-Device
OASIS	O
.	O
</s>
<s>
Rather	O
than	O
fight	O
a	O
long	O
and	O
expensive	O
court	O
battle	O
,	O
the	O
company	O
and	O
product	O
was	O
renamed	O
"	O
THEOS	B-Device
"	O
.	O
</s>
<s>
Williams	O
created	O
a	O
new	O
company	O
and	O
product	O
name	O
:	O
"	O
THEOS	B-Device
"	O
meaning	O
"	O
the	O
OS	O
"	O
in	O
the	O
sense	O
of	O
"	O
the	O
one	O
"	O
(	O
"	O
Theos	B-Device
"	O
is	O
Greek	O
for	O
"	O
God	O
"	O
)	O
.	O
</s>
<s>
While	O
Williams	O
and	O
Sidorsky	O
where	O
fighting	O
in	O
the	O
court	O
the	O
manufacturers	O
had	O
no	O
16-bit	B-Device
multi-user	O
OS	O
.	O
</s>
<s>
That	O
led	O
to	O
the	O
agreement	O
between	O
Microsoft	O
and	O
Santa	O
Cruz	O
Operation	O
to	O
make	O
a	O
new	O
operating	B-General_Concept
system	I-General_Concept
based	O
on	O
Version	B-Operating_System
7	I-Operating_System
Unix	I-Operating_System
from	O
Bell	O
Labs	O
.	O
</s>
<s>
Microsoft	O
purchased	O
a	O
license	O
for	O
Version	B-Operating_System
7	I-Operating_System
UNIX	I-Operating_System
from	O
AT&T	O
in	O
1978	O
,	O
and	O
announced	O
on	O
August	O
25	O
,	O
1980	O
,	O
that	O
it	O
would	O
make	O
it	O
available	O
for	O
the	O
16-bit	B-Device
microcomputer	B-Architecture
market	O
.	O
</s>
<s>
Because	O
Microsoft	O
was	O
not	O
able	O
to	O
license	O
the	O
"	O
UNIX	B-Application
"	O
name	O
itself	O
,	O
called	O
Xenix	B-Application
.	O
</s>
<s>
Seiko	O
also	O
lost	O
patience	O
with	O
THEOS	B-Device
and	O
Williams	O
,	O
and	O
decided	O
to	O
make	O
their	O
own	O
OASIS	O
16-bit	B-Device
version	O
and	O
hired	O
Dr.	O
Jeffrey	O
Bahr	O
.	O
</s>
<s>
When	O
Xenix	B-Application
and	O
THEOS	B-Device
became	O
available	O
Seiko	O
did	O
decide	O
to	O
leave	O
this	O
market	O
.	O
</s>
<s>
Jeffrey	O
Bahr	O
started	O
CET	O
which	O
went	O
on	O
with	O
the	O
development	O
of	O
the	O
16-bit	B-Device
OASIS	O
compatible	O
software	O
.	O
</s>
<s>
CET	O
software	O
was	O
complete	O
compatible	O
with	O
OASIS/THEOS	O
and	O
allowed	O
these	O
users	O
to	O
go	O
into	O
the	O
Unix	B-Application
and	O
Microsoft	O
world	O
.	O
</s>
<s>
CET	O
Basic	O
is	O
compatible	O
with	O
THEOS	B-Device
BASIC	O
,	O
MultiUser	O
BASIC	O
,	O
OASIS	O
BASIC	O
,	O
and	O
UX-BASIC	O
.	O
</s>
<s>
This	O
means	O
you	O
can	O
keep	O
most	O
of	O
your	O
existing	O
source	O
code	O
,	O
and	O
using	O
W/32	O
BASIC	O
,	O
recompile	O
your	O
THEOS	B-Device
,	O
OASIS	O
,	O
or	O
UX-BASIC	O
programs	O
to	O
work	O
under	O
additional	O
operating	B-General_Concept
systems	I-General_Concept
such	O
as	O
Microsoft	B-Application
Windows	I-Application
,	O
Linux	B-Application
or	O
SCO	B-Operating_System
UNIX	I-Operating_System
.	O
</s>
<s>
THEOS	B-Device
operating	B-General_Concept
systems	I-General_Concept
have	O
been	O
distributed	O
by	O
THEOS	B-Device
Software	I-Device
Corporation	I-Device
in	O
Walnut	O
Creek	O
,	O
California	O
,	O
since	O
1983	O
.	O
</s>
<s>
As	O
of	O
2003	O
,	O
Phase	O
One	O
Systems	O
publishes	O
software	O
development	O
tools	O
for	O
THEOS(R )	O
systems	O
.	O
</s>
<s>
As	O
well	O
as	O
porting	O
tools	O
,	O
Phase	O
One	O
Systems	O
distributed	O
the	O
Freedom	O
query	O
package	O
and	O
Control	O
database	O
package	O
for	O
THEOS	B-Device
systems	O
,	O
used	O
to	O
bring	O
SQL-like	O
data	O
extraction	O
tools	O
to	O
third-party	O
software	O
packages	O
.	O
</s>
<s>
THEOS	B-Device
was	O
introduced	O
in	O
Europe	O
by	O
Fujitsu	O
and	O
other	O
hardware	O
manufacturers	O
30	O
years	O
ago	O
,	O
and	O
is	O
distributed	O
by	O
a	O
number	O
of	O
distributors	O
in	O
Great	O
Britain	O
,	O
Spain	O
,	O
Portugal	O
,	O
Germany	O
,	O
Italy	O
and	O
more	O
.	O
</s>
<s>
The	O
'	O
current	O
 '	O
version	O
is	O
THEOS	B-Device
Corona	O
Commercial	O
Release	O
6	O
,	O
which	O
was	O
released	O
in	O
December	O
2008	O
,	O
and	O
a	O
number	O
of	O
updates	O
have	O
been	O
released	O
since	O
that	O
time	O
.	O
</s>
<s>
Similar	O
in	O
concept	O
to	O
MP/M	B-Operating_System
or	O
UNIX	B-Application
,	O
THEOS	B-Device
uses	O
external	O
device	O
drivers	O
rather	O
than	O
a	O
kernel	O
,	O
allowing	O
it	O
to	O
be	O
more	O
portable	O
to	O
other	O
environments	O
,	O
though	O
support	O
has	O
been	O
primarily	O
directed	O
towards	O
industry-standard	O
hardware	O
(	O
i.e.	O
</s>
<s>
THEOS	B-Device
is	O
specifically	O
aimed	O
at	O
small	O
business	O
users	O
,	O
with	O
a	O
wide	O
range	O
of	O
vertical-market	O
applications	O
packages	O
being	O
developed	O
and	O
supported	O
by	O
individuals	O
and	O
companies	O
.	O
</s>
<s>
The	O
languages	O
distributed	O
with	O
THEOS	B-Device
include	O
THEOS	B-Device
Multi-User	O
Basic	O
and	O
C	B-Language
.	O
A	O
powerful	O
EXEC	O
shell	O
language	O
can	O
be	O
used	O
for	O
task	O
automation	O
or	O
to	O
produce	O
a	O
turnkey	O
system	O
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
object	O
file	O
format	O
is	O
proprietary	B-Application
,	O
and	O
the	O
operating	B-General_Concept
system	I-General_Concept
uses	O
Intel	O
"	O
protected	O
mode	O
"	O
to	O
further	O
increase	O
defence	O
against	O
buffer	B-General_Concept
overrun	I-General_Concept
attacks	I-General_Concept
.	O
</s>
<s>
The	O
following	O
list	O
of	O
commands	B-Application
are	O
supported	O
by	O
the	O
THEOS/OASIS	O
Command	O
String	O
Interpreter	O
(	O
CSI	O
)	O
.	O
</s>
<s>
BYTE	O
in	O
1985	O
stated	O
that	O
"	O
the	O
functionality	O
of	O
THEOS	B-Device
is	O
somewhere	O
between	O
MS-DOS	B-Application
and	O
UNIX	B-Application
"	O
.	O
</s>
<s>
The	O
magazine	O
criticized	O
the	O
documentation	O
's	O
quality	O
,	O
and	O
concluded	O
that	O
the	O
price	O
was	O
too	O
high	O
compared	O
to	O
other	O
multiuser	O
operating	B-General_Concept
systems	I-General_Concept
for	O
the	O
PC	O
such	O
as	O
Pick	B-Application
and	O
Coherent	B-Operating_System
.	O
</s>
