<s>
UNOS	B-Architecture
is	O
the	O
first	O
,	O
now	O
discontinued	O
,	O
32-bit	O
Unix-like	B-Operating_System
real-time	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
(	O
RTOS	B-Operating_System
)	O
with	O
real-time	B-General_Concept
extensions	O
.	O
</s>
<s>
It	O
was	O
developed	O
by	O
Jeffery	O
Goldberg	O
,	O
MS	O
.	O
who	O
left	O
Bell	O
Labs	O
after	O
using	O
Unix	B-Application
and	O
became	O
VP	O
of	O
engineering	O
for	O
Charles	O
River	O
Data	O
Systems	O
(	O
CRDS	O
)	O
,	O
now	O
defunct	O
.	O
</s>
<s>
UNOS	B-Architecture
was	O
written	O
to	O
capitalize	O
on	O
the	O
first	O
32-bit	O
microprocessor	O
,	O
the	O
Motorola	B-Device
68k	I-Device
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
(	O
CPU	O
)	O
.	O
</s>
<s>
CRDS	O
sold	O
a	O
UNOS	B-Architecture
based	O
68K	B-Device
system	O
,	O
and	O
sold	O
porting	O
services	O
and	O
licenses	O
to	O
other	O
manufacturers	O
who	O
had	O
embedded	O
CPUs	O
.	O
</s>
<s>
Jeff	O
Goldberg	O
created	O
an	O
experimental	O
OS	O
using	O
only	O
eventcounts	O
for	O
synchronization	O
,	O
that	O
allowed	O
a	O
preemptive	O
kernel	O
,	O
for	O
a	O
Charles	O
River	O
Data	O
Systems	O
(	O
CRDS	O
)	O
PDP-11	B-Device
.	O
</s>
<s>
CRDS	O
hired	O
Goldberg	O
to	O
create	O
UNOS	B-Architecture
and	O
began	O
selling	O
it	O
in	O
1981	O
.	O
</s>
<s>
UNOS	B-Architecture
was	O
written	O
for	O
the	O
Motorola	B-Device
68000	I-Device
series	I-Device
processors	O
.	O
</s>
<s>
While	O
compatible	O
with	O
Version	B-Operating_System
7	I-Operating_System
Unix	I-Operating_System
,	O
it	O
is	O
also	O
an	O
RTOS	B-Operating_System
.	O
</s>
<s>
CRDS	O
supported	O
it	O
on	O
the	O
company	O
's	O
Universe	O
68	O
computers	O
,	O
as	O
did	O
Motorola	O
's	O
Versabus	B-Architecture
systems	O
.	O
</s>
<s>
CRDS	O
's	O
primary	O
market	O
was	O
OEMs	O
embedding	O
the	O
CRDS	O
unit	O
within	O
a	O
larger	O
pile	O
of	O
hardware	O
,	O
often	O
requiring	O
better	O
real-time	B-General_Concept
response	O
than	O
Unix	B-Application
could	O
deliver	O
.	O
</s>
<s>
UNOS	B-Architecture
has	O
a	O
cleaner	O
kernel	O
interface	O
than	O
UNIX	B-Application
in	O
1981	O
.	O
</s>
<s>
There	O
was	O
e.g.	O
,	O
a	O
system	O
call	O
to	O
obtain	O
ps	B-Application
information	O
instead	O
of	O
reading	O
/dev/kmem	O
.	O
</s>
<s>
UNOS	B-Architecture
required	O
memory	O
protection	O
,	O
with	O
the	O
68000	O
using	O
an	O
MMU	O
developed	O
by	O
CRDS	O
;	O
and	O
only	O
used	O
Motorola	O
MMUs	O
after	O
UNOS	B-Architecture
7	O
on	O
the	O
68020	B-Device
(	O
CRDS	O
System	O
CP20	O
)	O
(	O
using	O
the	O
MC68851	B-General_Concept
PMMU	O
)	O
.	O
</s>
<s>
UNOS	B-Architecture
was	O
written	O
in	O
the	O
programming	O
languages	O
C	B-Language
and	O
assembly	B-Language
language	I-Language
,	O
and	O
supported	O
Fortran	B-Application
,	O
COBOL	B-Application
,	O
Pascal	B-Application
,	O
and	O
Business	B-Language
Basic	I-Language
.	O
</s>
<s>
UNOS	B-Architecture
from	O
CRDS	O
never	O
supported	O
paged	O
virtual	O
memory	O
and	O
multiprocessor	O
support	O
had	O
not	O
been	O
built	O
in	O
from	O
the	O
start	O
,	O
so	O
the	O
kernel	O
remained	O
mostly	O
single-threaded	O
on	O
the	O
few	O
multiprocessor	O
systems	O
built	O
.	O
</s>
<s>
A	O
UNOS	B-Architecture
variant	O
enhanced	O
by	O
H	O
.	O
Berthold	O
AG	O
under	O
the	O
name	O
vBertOS	O
added	O
demanded	O
page	O
loading	O
and	O
paged	O
processes	O
in	O
1984	O
,	O
but	O
was	O
given	O
up	O
in	O
favor	O
of	O
SunOS	B-Operating_System
because	O
of	O
the	O
missing	O
GUI	O
and	O
the	O
missing	O
networking	O
code	O
in	O
Spring	O
1985	O
,	O
when	O
Berthold	O
imported	O
the	O
first	O
Sun	O
to	O
Europe	O
.	O
</s>
