<s>
Since	O
the	O
invention	O
of	O
the	O
floppy	B-Device
disk	I-Device
drive	I-Device
,	O
various	O
standardized	O
form	O
factors	O
have	O
been	O
used	O
in	O
computing	O
systems	O
.	O
</s>
<s>
Drives	O
may	O
slot	O
into	O
a	O
drive	B-Device
bay	I-Device
of	O
the	O
corresponding	O
size	O
.	O
</s>
<s>
Compared	O
to	O
flash	B-Device
drives	I-Device
in	O
same	O
form	O
factor	O
,	O
maximum	O
rotating	O
disk	O
drive	O
capacity	O
is	O
much	O
smaller	O
,	O
with	O
100TB	O
,	O
and	O
32TB	O
for	O
2.5-inch	O
.	O
</s>
<s>
In	O
1962	O
,	O
IBM	O
introduced	O
its	O
model	B-Device
1311	I-Device
disk	O
,	O
which	O
used	O
six	O
14-inch	O
(	O
nominal	O
size	O
)	O
platters	O
in	O
a	O
removable	O
pack	O
and	O
was	O
roughly	O
the	O
size	O
of	O
a	O
washing	O
machine	O
.	O
</s>
<s>
The	O
IBM	B-Device
2314	I-Device
used	O
platters	O
of	O
the	O
same	O
size	O
in	O
an	O
eleven-high	O
pack	O
and	O
introduced	O
the	O
"	O
drive	O
in	O
a	O
drawer	O
"	O
layout	O
,	O
although	O
the	O
"	O
drawer	O
"	O
was	O
not	O
the	O
complete	O
drive	O
.	O
</s>
<s>
Later	O
drives	O
were	O
designed	O
to	O
fit	O
entirely	O
into	O
a	O
chassis	O
that	O
would	O
mount	O
in	O
a	O
19-inch	B-Application
rack	I-Application
.	O
</s>
<s>
Digital	O
's	O
RK05	B-Device
and	O
RL01	O
were	O
early	O
examples	O
using	O
single	O
14-inch	O
platters	O
in	O
removable	O
packs	O
,	O
the	O
entire	O
drive	O
fitting	O
in	O
a	O
10.5-inch-high	O
rack	O
space	O
(	O
six	O
rack	O
units	O
)	O
.	O
</s>
<s>
In	O
the	O
mid-to-late	O
1980s	O
the	O
similarly	O
sized	O
Fujitsu	B-Device
Eagle	I-Device
,	O
which	O
used	O
(	O
coincidentally	O
)	O
10.5-inch	O
platters	O
,	O
was	O
a	O
popular	O
product	O
.	O
</s>
<s>
With	O
increasing	O
sales	O
of	O
microcomputers	O
having	O
built	O
in	O
floppy-disk	B-Device
drives	I-Device
(	O
FDDs	O
)	O
,	O
HDDs	O
that	O
would	O
fit	O
to	O
the	O
FDD	O
mountings	O
became	O
desirable	O
.	O
</s>
<s>
Thus	O
HDD	O
Form	O
factors	O
,	O
initially	O
followed	O
those	O
of	O
8-inch	O
,	O
5.25-inch	O
,	O
and	O
3.5-inch	O
floppy	B-Device
disk	I-Device
drives	I-Device
.	O
</s>
<s>
Because	O
there	O
were	O
no	O
smaller	O
floppy	B-Device
disk	I-Device
drives	I-Device
,	O
smaller	O
HDD	O
form	O
factors	O
developed	O
from	O
product	O
offerings	O
or	O
industry	O
standards	O
.	O
</s>
<s>
In	O
1979	O
,	O
Shugart	O
Associates	O
 '	O
SA1000	O
was	O
the	O
first	O
form	O
factor	O
compatible	O
HDD	O
,	O
having	O
the	O
same	O
dimensions	O
and	O
a	O
compatible	O
interface	O
to	O
the	O
8	B-Device
"	I-Device
FDD	O
.	O
</s>
<s>
This	O
smaller	O
form	O
factor	O
,	O
first	O
used	O
in	O
an	O
HDD	O
by	O
Seagate	O
in	O
1980	O
,	O
was	O
the	O
same	O
size	O
as	O
full-height	B-Device
FDD	O
,	O
3.25-inches	O
high	O
.	O
</s>
<s>
The	O
Quantum	B-Device
Bigfoot	I-Device
HDD	O
was	O
the	O
last	O
to	O
use	O
it	O
in	O
the	O
late	O
1990s	O
,	O
with	O
"	O
low-profile	O
"	O
( ≈25mm	O
)	O
and	O
"	O
ultra-low-profile	O
"	O
( ≈20mm	O
)	O
high	O
versions	O
.	O
</s>
<s>
The	O
2.5-inch	O
drive	O
format	O
is	O
standardized	O
in	O
the	O
EIA/ECA	O
-720	O
co-published	O
as	O
SFF-8201	O
;	O
when	O
used	O
with	O
specific	O
connectors	O
,	O
more	O
detailed	O
specifications	O
are	O
SFF-8212	O
for	O
the	O
50-pin	O
(	O
ATA	O
laptop	O
)	O
connector	O
,	O
SFF-8223	O
with	O
the	O
SATA	O
,	O
or	O
SAS	O
connector	O
and	O
SFF-8222	O
with	O
the	O
SCA-2	B-Architecture
connector	O
.	O
</s>
<s>
and	O
for	O
solid-state	B-Device
drives	I-Device
(	O
SSDs	B-Device
)	O
,	O
by	O
2008	O
replacing	O
some	O
3.5inch	O
enterprise-class	O
drives	O
.	O
</s>
<s>
It	O
is	O
also	O
used	O
in	O
the	O
PlayStation	B-Operating_System
3	I-Operating_System
and	O
Xbox	B-Operating_System
360	I-Operating_System
video	O
game	O
consoles	O
.	O
</s>
<s>
Western	O
Digital	O
released	O
on	O
April	O
23	O
,	O
2013	O
a	O
hard	O
drive	O
5mm	O
in	O
height	O
specifically	O
aimed	O
at	O
Ultrabooks	B-Device
.	O
</s>
<s>
The	O
1.8	O
inch	O
form	O
factor	O
was	O
used	O
in	O
digital	O
audio	O
players	O
and	O
subnotebooks	B-Device
with	O
a	O
ZIF	O
connector	O
.	O
</s>
<s>
The	O
1.8	O
inch	O
form	O
factor	O
was	O
eventually	O
phased	O
out	O
as	O
SSD	B-Device
drives	I-Device
became	O
cheaper	O
to	O
produce	O
and	O
could	O
be	O
built	O
directly	O
onto	O
PCBs	O
to	O
save	O
space	O
.	O
</s>
<s>
This	O
form	O
factor	O
was	O
used	O
by	O
HP	O
C3013A	O
,	O
C3013B	O
and	O
C3014A	O
,	O
named	O
HP	B-Device
Kittyhawk	I-Device
microdrive	I-Device
,	O
introduced	O
in	O
June	O
1992	O
.	O
</s>
<s>
This	O
form	O
factor	O
was	O
introduced	O
in	O
1999	O
,	O
as	O
IBM	O
's	O
Microdrive	B-Device
to	O
fit	O
inside	O
a	O
CF	B-Device
Type	O
II	O
slot	O
.	O
</s>
<s>
Toshiba	O
announced	O
this	O
form	O
factor	O
in	O
January	O
2004	O
for	O
use	O
in	O
mobile	O
phones	O
and	O
similar	O
applications	O
,	O
including	O
SD/MMC	O
slot	O
compatible	O
HDDs	O
optimized	O
for	O
video	O
storage	O
on	O
4G	B-Architecture
handsets	O
.	O
</s>
<s>
By	O
2009	O
,	O
all	O
manufacturers	O
had	O
discontinued	O
the	O
development	O
of	O
new	O
products	O
for	O
the	O
1.3-inch	O
,	O
1-inch	O
and	O
0.85-inch	O
form	O
factors	O
due	O
to	O
falling	O
prices	O
of	O
flash	B-Device
memory	I-Device
,	O
which	O
has	O
no	O
moving	O
parts	O
.	O
</s>
