<s>
BLIS/COBOL	B-Operating_System
is	O
a	O
discontinued	O
operating	B-General_Concept
system	I-General_Concept
that	O
was	O
written	O
in	O
COBOL	B-Application
.	O
</s>
<s>
It	O
was	O
optimised	O
to	O
compile	B-Language
business	O
applications	O
written	O
in	O
COBOL	B-Application
.	O
</s>
<s>
BLIS	O
was	O
available	O
on	O
a	O
range	O
of	O
Data	B-Device
General	I-Device
Nova	I-Device
and	O
Data	B-Device
General	I-Device
Eclipse	I-Device
16-bit	B-Device
minicomputers	B-Architecture
.	O
</s>
<s>
By	O
1985	O
,	O
a	O
version	O
for	O
the	O
IBM	B-Device
PC	I-Device
existed	O
called	O
PC-BLIS	O
.	O
</s>
<s>
Originally	O
,	O
most	O
operating	B-General_Concept
systems	I-General_Concept
were	O
written	O
in	O
assembly	B-Language
language	I-Language
for	O
a	O
particular	O
processor	B-General_Concept
or	O
family	O
of	O
processors	O
.	O
</s>
<s>
Non-assembler	O
operating	B-General_Concept
systems	I-General_Concept
were	O
comparatively	O
slow	O
,	O
but	O
were	O
easier	O
for	O
revision	O
and	O
repair	O
.	O
</s>
<s>
One	O
of	O
the	O
reasons	O
for	O
the	O
C	B-Language
programming	I-Language
language	I-Language
's	O
low-level	O
features	O
,	O
which	O
resemble	O
assembly	B-Language
language	I-Language
in	O
some	O
ways	O
,	O
is	O
an	O
early	O
intent	O
to	O
use	O
it	O
for	O
writing	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
Similar	O
goals	O
led	O
to	O
IBM	O
's	O
development	O
of	O
PL/S	B-Language
.	O
</s>
<s>
The	O
high-level	O
nature	O
of	O
COBOL	B-Application
,	O
which	O
created	O
some	O
problems	O
for	O
operating	B-General_Concept
system	I-General_Concept
development	O
,	O
was	O
partially	O
addressed	O
in	O
BLIS	O
,	O
since	O
it	O
was	O
deliberately	O
optimized	O
for	O
COBOL	B-Application
.	O
</s>
