<s>
The	O
Commodore	B-Device
900	I-Device
(	O
also	O
known	O
as	O
the	O
C900	O
,	O
Z-8000	O
,	O
and	O
Z-Machine	O
)	O
was	O
a	O
prototype	B-Application
microcomputer	B-Architecture
originally	O
intended	O
for	O
business	O
computing	O
and	O
,	O
later	O
,	O
as	O
an	O
affordable	O
UNIX	B-Device
workstation	I-Device
.	O
</s>
<s>
It	O
was	O
to	O
replace	O
the	O
aging	O
PET/CBM	O
families	O
of	O
personal	O
computers	O
that	O
had	O
found	O
success	O
in	O
Europe	O
as	O
business	O
machines	O
.	O
</s>
<s>
In	O
early	O
1983	O
,	O
Commodore	O
announced	O
an	O
agreement	O
with	O
Zilog	O
to	O
adopt	O
the	O
Z8000	B-Device
family	O
of	O
processors	O
for	O
its	O
next	O
generation	O
of	O
computers	O
,	O
conferring	O
rights	O
to	O
Commodore	O
to	O
manufacture	O
these	O
processors	O
and	O
for	O
Zilog	O
to	O
manufacture	O
various	O
Commodore-designed	O
integrated	O
circuit	O
products	O
.	O
</s>
<s>
Commodore	O
had	O
reportedly	O
been	O
developing	O
its	O
own	O
16-bit	B-Device
microprocessor	O
,	O
abandoning	O
this	O
effort	O
to	O
adopt	O
the	O
Z8000	B-Device
.	O
</s>
<s>
The	O
C900	O
was	O
a	O
16-bit	B-Device
computer	I-Device
based	O
on	O
the	O
segmented	O
version	O
of	O
the	O
Zilog	B-Device
Z8000	I-Device
CPU	B-General_Concept
.	O
</s>
<s>
Initial	O
announcements	O
indicated	O
the	O
use	O
of	O
a	O
10MHz	O
Z8001	B-Device
processor	O
,	O
but	O
earlier	O
technical	O
documentation	O
suggested	O
the	O
use	O
of	O
a	O
6MHz	O
part	O
and	O
detailed	O
the	O
option	O
of	O
a	O
Z8070	O
arithmetic	O
processing	O
unit	O
(	O
APU	O
)	O
running	O
at	O
24MHz	O
.	O
</s>
<s>
Two	O
versions	O
of	O
the	O
machine	O
were	O
developed	O
:	O
a	O
workstation	B-Device
with	O
pixel	B-Algorithm
graphics	O
and	O
a	O
multi-user	O
system	O
featuring	O
a	O
text-only	O
display	O
intended	O
to	O
act	O
as	O
a	O
server	B-Application
for	O
a	O
number	O
of	O
connected	O
character-based	O
terminals	O
.	O
</s>
<s>
The	O
high-resolution	O
display	O
option	O
employed	O
128KB	O
of	O
dedicated	O
video	O
memory	O
and	O
featured	O
hardware	O
support	O
for	O
blitting	B-Algorithm
operations	O
,	O
this	O
being	O
employed	O
by	O
a	O
graphical	O
environment	O
featuring	O
"	O
multiple	O
overlapping	O
windows	O
"	O
.	O
</s>
<s>
The	O
C900	O
ran	O
Coherent	B-Operating_System
,	O
a	O
UNIX-like	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
,	O
claimed	O
in	O
publicity	O
as	O
being	O
"	O
fully	O
compatible	O
with	O
T	O
's	O
Unix	O
System	O
V	O
,	O
version	O
5.2	O
"	O
,	O
although	O
the	O
Coherent	B-Operating_System
system	O
was	O
generally	O
regarded	O
as	O
merely	O
providing	O
a	O
level	O
of	O
compatibility	O
with	O
Version	B-Operating_System
7	I-Operating_System
Unix	I-Operating_System
.	O
</s>
<s>
Onyx	O
Systems	O
,	O
a	O
pioneer	O
of	O
Z8000-based	O
systems	O
running	O
Unix	O
,	O
had	O
previously	O
delivered	O
ports	O
of	O
Version	B-Operating_System
7	I-Operating_System
Unix	I-Operating_System
and	O
Unix	B-Operating_System
System	I-Operating_System
III	I-Operating_System
for	O
their	O
computers	O
.	O
</s>
<s>
Ultimately	O
,	O
only	O
fifty	O
prototypes	B-Application
were	O
made	O
and	O
sold	O
as	O
development	O
systems	O
before	O
the	O
project	O
was	O
cancelled	O
.	O
</s>
<s>
The	O
C900	O
's	O
case	O
is	O
similar	O
to	O
the	O
Amiga	B-Device
2000	I-Device
's	O
but	O
slightly	O
larger	O
.	O
</s>
