<s>
Time	B-Operating_System
Sharing	I-Operating_System
Operating	I-Operating_System
System	I-Operating_System
,	O
or	O
TSOS	O
,	O
is	O
a	O
discontinued	O
operating	B-General_Concept
system	I-General_Concept
for	O
RCA	O
mainframe	B-Architecture
computers	I-Architecture
of	O
the	O
Spectra	B-Device
70	I-Device
series	O
.	O
</s>
<s>
TSOS	O
quickly	O
evolved	O
into	O
the	O
Virtual	B-Operating_System
Memory	I-Operating_System
Operating	I-Operating_System
System	I-Operating_System
(	O
VMOS	O
)	O
by	O
1970	O
.	O
</s>
<s>
In	O
the	O
mid	O
seventies	O
,	O
an	O
enhanced	O
version	O
of	O
TSOS	O
called	O
BS2000	B-Application
was	O
offered	O
by	O
the	O
German	O
company	O
Siemens	O
.	O
</s>
<s>
While	O
Sperry	O
now	O
Unisys	O
discontinued	O
VS/9	O
,	O
the	O
BS2000	B-Application
variant	O
,	O
now	O
called	O
BS2000/OSD	B-Application
,	O
is	O
still	O
offered	O
by	O
Fujitsu	O
and	O
used	O
by	O
their	O
mainframe	B-Architecture
customers	O
primarily	O
in	O
Germany	O
and	O
other	O
European	O
countries	O
.	O
</s>
<s>
As	O
the	O
name	O
suggests	O
,	O
TSOS	O
provided	O
time	B-General_Concept
sharing	I-General_Concept
features	O
.	O
</s>
<s>
Similar	O
to	O
CTSS	B-Operating_System
it	O
provided	O
a	O
common	O
user	O
interface	O
for	O
both	O
time	B-General_Concept
sharing	I-General_Concept
and	O
batch	B-General_Concept
,	O
which	O
was	O
a	O
big	O
advantage	O
over	O
IBM	O
's	O
OS/360	B-Application
or	O
its	O
successors	O
MVS	B-Application
,	O
OS/390	B-Application
and	O
z/OS	B-Application
.	O
</s>
