NOVEMBER 2004 MA XIMUMPC 55
When^ t
he^ IBM^
PC^ shou
ldered^
its^ way^
into^ the
compu
ter^ mark
etplace
in^1981
, it^proudly
boasted
a^ state- of-the-
art^ Intel
8088 ce
ntral^ pr
ocessin
g^ unit^ u
nder^ the
hood.^
The^80
88 chug
ged^ alo
ng^ at^4.
77 MHz,^
had^ no^
internal
math^ c
oproces
sor^ (cal
led^ the^8087 ,^ th
is^ exter
nal^ optio
n^ cost^
an^ extra
$^500 ),^
used^ a^
16 - bit^ in
ternal^ d
ata^ bus
, an^8 -bit^ exte
rnal^ da
ta^ bus^ to
mainta
in^ com
patibility
with^ e
xisting^ c
ompute
r comp
o-nents,^ a
nd^ con
tained^ a
record-
breakin
g^29 ,^000
transis
tors.^In^ ca
se^ you^ weren’t^ p
aying^ at
tention,
the^ inte
rnal^ tra
nsistor^
count^ oftoday’s
CPUs^ h
as^ incr
eased^ b
y^ a^ fact
or^ of^6 ,^0
00 sinc
e^ then.^
Amazin
gly,^the^ phy
sical^ siz
e of^ the
CPU^ co
re^ hasn
’t^ gotten
any^ bi
gger^ (it^
remainsroughl
y^ the^ si
ze^ of^ a^ t
humbn
ail).^The^ cre
ation^ o
f a^ CPU^
with^17
8 millio
n transi
stors^ is,
not^ sur
prisingl
y,^ a^vastly^ c
omplex
process
that^ in
volves^ c
hemica
l broths
, ultrav
iolet^ lig
ht,^ and^
the^ delicate^ ac
t of^ slic
ing^ silic
on^ cylin
ders^ in^
order^ to
etch^ de
signs^ t
hat^ are^
invisible
to^ the^
naked^eye.^ An
d—reali
ze^ we^ s
ay^ this^ with^ a^ lar
ge^ dose
of^ irony
—the^ p
rocess^
also^ reli
es^ heav
ily^ on^the^ ass
istance
of^ othe
r compu
ters.Whi
le^ proce
ssor^ m
anufactu
rers^ all
have^ th
eir^ own
propri
etary^ pa
rlor^ tric
ks,^ CPU
design
involve
s^ the^same^ fu
ndame
ntal^ pro
cesses,^
and^ tha
t’s^ what
we’re^ g
oing^ to
show^ y
ou^ toda
y—six^
essentia
l steps^
in^ con-tempor
ary^ pro
cessor^ d
esign^ a
nd^ man
ufactur
e.^ So^ sl
ip^ into^ y
our^ bu
nny^ suit
and^ en
joy^ the^
show!MAXIMUM PC EXPLAINS THE
HO
W^ PC^ P
RO
CESSO
RS^
AR
E^BY BILL O’BRIEN
CO
NC
EIV
ED
,^ D
ES
IG
NED^ A
ND
M
AD
E