<s>
A	O
computer	B-General_Concept
lock	I-General_Concept
is	O
a	O
physical	O
lock	O
on	O
a	O
computer	O
with	O
an	O
accompanying	O
key	O
used	O
for	O
access	O
control	O
or	O
as	O
an	O
anti-theft	O
system	O
.	O
</s>
<s>
In	O
the	O
1980s	O
and	O
early	O
1990s	O
,	O
IBM	B-Device
Personal	I-Device
Computers	I-Device
and	O
some	O
PC	O
compatibles	O
included	O
a	O
tubular	O
pin	O
tumbler	O
lock	O
on	O
the	O
computer	O
's	O
casing	O
performing	O
a	O
security	O
function	O
that	O
varied	O
by	O
manufacturer	O
.	O
</s>
<s>
Other	O
early	O
personal	O
computer	B-General_Concept
locks	I-General_Concept
include	O
Maclocks	B-Operating_System
,	O
introduced	O
by	O
Compulocks	O
in	O
1986	O
.	O
</s>
<s>
Built-in	O
computer	B-General_Concept
locks	I-General_Concept
for	O
access	O
control	O
were	O
phased	O
out	O
by	O
computer	O
manufacturers	O
in	O
the	O
1990s	O
as	O
operating	O
systems	O
and	O
other	O
software	O
incorporated	O
user	O
profiles	O
with	O
passwords	O
,	O
but	O
computer	B-General_Concept
locks	I-General_Concept
to	O
prevent	O
theft	O
are	O
still	O
in	O
use	O
,	O
more	O
commonly	O
in	O
the	O
form	O
of	O
Kensington	O
locks	O
that	O
attach	O
cables	O
to	O
laptops	O
and	O
small	O
desktops	O
in	O
an	O
effort	O
to	O
prevent	O
them	O
from	O
being	O
taken	O
.	O
</s>
