<s>
Intel	O
's	O
i486	B-General_Concept
OverDrive	O
processors	O
are	O
a	O
category	O
of	O
various	O
Intel	B-General_Concept
80486s	I-General_Concept
that	O
were	O
produced	O
with	O
the	O
designated	O
purpose	O
of	O
being	O
used	O
to	O
upgrade	B-General_Concept
personal	B-Device
computers	I-Device
.	O
</s>
<s>
The	O
OverDrives	O
typically	O
possessed	O
qualities	O
different	O
from	O
'	O
standard	O
 '	O
i486s	B-General_Concept
with	O
the	O
same	O
speed	O
steppings	O
.	O
</s>
<s>
Those	O
included	O
built-in	O
voltage	O
regulators	O
,	O
different	O
pin-outs	O
,	O
write-back	B-General_Concept
cache	I-General_Concept
instead	O
of	O
write-through	B-General_Concept
cache	I-General_Concept
,	O
built-in	O
heatsinks	O
,	O
and	O
fanless	O
operation	O
—	O
features	O
that	O
made	O
them	O
more	O
able	O
to	O
work	O
where	O
an	O
ordinary	O
edition	O
of	O
a	O
particular	O
model	O
would	O
not	O
.	O
</s>
<s>
Each	O
486	B-Device
Overdrive	I-Device
typically	O
came	O
in	O
two	O
versions	O
,	O
ODP	O
and	O
ODPR	O
variants	O
.	O
</s>
<s>
The	O
ODPR	O
chips	O
had	O
168	O
pins	O
and	O
functioned	O
as	O
complete	O
swap-out	O
replacements	O
for	O
existing	O
chips	O
,	O
whereas	O
the	O
ODP	O
chips	O
had	O
an	O
extra	O
169th	O
pin	O
,	O
and	O
were	O
used	O
for	O
inserting	O
into	O
a	O
special	O
'	O
Overdrive	O
 '	O
(	O
Socket	B-Device
1	I-Device
)	O
socket	O
on	O
some	O
486	B-General_Concept
boards	O
,	O
which	O
would	O
disable	O
the	O
existing	O
CPU	O
without	O
needing	O
to	O
remove	O
it	O
(	O
in	O
case	O
that	O
the	O
existing	O
CPU	O
is	O
surface-mounted	O
)	O
.	O
</s>
<s>
ODP	O
chips	O
will	O
not	O
work	O
in	O
Pre-Socket	O
1	O
486	B-General_Concept
boards	O
due	O
to	O
the	O
extra	O
pin	O
.	O
</s>
