<s>
The	O
386SLC	B-Device
was	O
an	O
Intel-licensed	O
version	O
of	O
the	O
386SX	O
(	O
32-bit	O
internal	O
,	O
16-bit	B-Device
external	O
,	O
24-bit	O
memory	O
addressing	O
)	O
,	O
developed	O
and	O
manufactured	O
by	O
IBM	O
in	O
1991	O
.	O
</s>
<s>
It	O
included	O
power-management	O
capabilities	O
and	O
an	O
8KB	O
internal	O
CPU	B-General_Concept
cache	I-General_Concept
,	O
which	O
enabled	O
it	O
to	O
yield	O
comparable	O
performance	O
to	O
386DX	B-General_Concept
processors	O
of	O
the	O
same	O
clock	O
speed	O
,	O
which	O
were	O
considerably	O
more	O
expensive	O
.	O
</s>
<s>
Known	O
inside	O
IBM	O
as	O
"	O
Super	O
Little	O
Chip	O
"	O
for	O
its	O
initials	O
,	O
it	O
was	O
used	O
in	O
the	O
IBM	B-Device
PS/2	I-Device
35	O
,	O
40	O
and	O
56	O
Series	O
and	O
in	O
the	O
IBM	B-Device
PS/ValuePoint	I-Device
325T	O
,	O
but	O
never	O
gained	O
much	O
market	O
share	O
.	O
</s>
<s>
This	O
was	O
mainly	O
due	O
to	O
an	O
agreement	O
with	O
Intel	O
,	O
in	O
which	O
IBM	O
was	O
not	O
allowed	O
to	O
sell	O
their	O
CPUs	O
if	O
they	O
were	O
not	O
part	O
of	O
a	O
system	O
or	O
upgrade	B-General_Concept
board	O
.	O
</s>
<s>
It	O
was	O
also	O
marketed	O
as	O
an	O
optional	O
upgrade	B-General_Concept
for	O
8086-equipped	O
IBM	B-Device
PS/2	I-Device
25	O
Series	O
computers	O
.	O
</s>
<s>
Built	O
with	O
complementary	O
metal	O
oxide	O
semiconductor	O
(	O
CMOS	B-Device
)	O
technology	O
,	O
the	O
IBM	B-Device
386SLC	I-Device
had	O
a	O
161-square	O
millimeter	O
die	O
.	O
</s>
<s>
The	O
25MHz	O
model	O
produced	O
only	O
2.5	O
watts	O
of	O
dissipated	O
power	O
,	O
making	O
it	O
especially	O
well	O
suited	O
for	O
laptops	B-Device
and	O
other	O
portable	O
devices	O
.	O
</s>
<s>
Despite	O
the	O
fact	O
that	O
the	O
SLC	O
and	O
DLC	O
chips	O
are	O
bus	O
compatible	O
with	O
i386SX	O
and	O
i386DX	B-General_Concept
respectively	O
,	O
they	O
can	O
not	O
be	O
used	O
as	O
drop-in	O
replacements	O
as	O
they	O
are	O
not	O
pin-compatible	O
.	O
</s>
<s>
The	O
486SLC	O
is	O
an	O
improved	O
version	O
of	O
the	O
IBM	B-Device
386SLC	I-Device
,	O
based	O
on	O
the	O
Intel	O
core	O
.	O
</s>
<s>
IBM	O
486SLC	O
featured	O
16KB	O
of	O
L1	O
cache	O
and	O
the	O
i486	B-General_Concept
instruction	B-General_Concept
set	I-General_Concept
.	O
</s>
<s>
It	O
had	O
1.349	O
million	O
transistors	B-Application
and	O
a	O
69mm²	O
die	O
.	O
</s>
<s>
It	O
came	O
in	O
a	O
100-pin	O
BQFP	O
package	O
,	O
with	O
33MHz	O
FSB	B-Architecture
speed	O
.	O
</s>
<s>
Clock-for-clock	O
,	O
it	O
was	O
substantially	O
faster	O
than	O
the	O
similarly-named	O
Cyrix	O
part	O
,	O
yielding	O
performance	O
broadly	O
comparable	O
to	O
a	O
similarly-clocked	O
486SX	B-Device
in	O
the	O
16-bit	B-Device
applications	O
of	O
its	O
day	O
.	O
</s>
<s>
However	O
,	O
its	O
narrow	O
16-bit	B-Device
bus	O
,	O
limited	O
memory	O
addressing	O
capability	O
(	O
16	O
MB	O
)	O
and	O
lack	O
of	O
on-chip	O
FPU	O
would	O
prove	O
to	O
be	O
major	O
disadvantages	O
under	O
the	O
new	O
generation	O
of	O
32-bit	O
operating	O
systems	O
(	O
such	O
as	O
Windows	B-Application
95	I-Application
)	O
that	O
would	O
become	O
popular	O
in	O
following	O
years	O
.	O
</s>
<s>
All	O
known	O
instances	O
of	O
486SLC3	O
CPUs	O
are	O
reportedly	O
in	O
the	O
132-pin	O
PQFP	O
packaging	O
with	O
the	O
extra	O
address	O
lines	O
not	O
connected	O
(	O
a	O
486BL3	O
running	O
in	O
16-bit	B-Device
mode	O
)	O
.	O
</s>
<s>
The	O
486BL	O
is	O
a	O
fully	O
32-bit	O
version	O
of	O
the	O
486SLC	O
,	O
with	O
1.4	O
million	O
transistors	B-Application
on	O
a	O
82mm²	O
die	O
,	O
using	O
a	O
0.8µm	O
CMOS	B-Device
process	O
.	O
</s>
<s>
It	O
came	O
in	O
a	O
132-pin	O
QFP	B-Algorithm
package	O
.	O
</s>
<s>
IBM	O
later	O
marketed	O
Socket	B-General_Concept
3	I-General_Concept
168-pin	O
PGA	O
Blue	O
Lightning	O
486	B-General_Concept
CPUs	O
,	O
but	O
these	O
are	O
technically	O
not	O
related	O
to	O
earlier	O
Blue	O
Lightning	O
models	O
as	O
they	O
are	O
based	O
on	O
the	O
Cyrix	B-Device
Cx486	I-Device
CPU	O
core	O
.	O
</s>
<s>
They	O
can	O
be	O
distinguished	O
by	O
the	O
inclusion	O
of	O
a	O
"	O
DX	O
"	O
(	O
or	O
DX2	O
,	O
DX4	O
)	O
legend	O
somewhere	O
on	O
the	O
label	O
,	O
setting	O
them	O
apart	O
from	O
the	O
earlier	O
386-derived	O
,	O
nominally	O
486SX-equivalent	O
processors	O
.	O
</s>
<s>
As	O
a	O
result	O
the	O
first-generation	O
BLs	O
are	O
often	O
commonly	O
referred	O
to	O
as	O
"	O
486DLC	O
"	O
(	O
and	O
486DLC2	O
,	O
DLC3/4	O
)	O
CPUs	O
,	O
a	O
logical	O
and	O
386-alike	O
progression	O
from	O
the	O
16-bit	B-Device
SLC	O
models	O
-	O
even	O
though	O
IBM	O
themselves	O
do	O
not	O
appear	O
to	O
have	O
used	O
that	O
name	O
in	O
any	O
official	O
materials	O
,	O
simply	O
calling	O
them	O
"	O
Blue	O
Lightning	O
"	O
or	O
shortening	O
the	O
name	O
to	O
"	O
486BL	O
"	O
.	O
</s>
<s>
The	O
"	O
486DLC	O
"	O
name	O
itself	O
is	O
instead	O
one	O
used	O
by	O
Cyrix	O
for	O
their	O
wholly	O
distinct	O
(	O
from	O
IBM/Intel	O
'	O
s	O
product	O
)	O
predecessors	O
to	O
the	O
"	O
4x86	O
"	O
generation	O
(	O
itself	O
the	O
basis	O
of	O
IBM	O
's	O
later	O
486DX	B-General_Concept
line	O
)	O
,	O
as	O
openly	O
and	O
clearly	O
printed	O
on	O
the	O
processor	O
cases	O
.	O
</s>
