<s>
A	O
drive	B-Device
bay	I-Device
is	O
a	O
standard-sized	O
area	O
for	O
adding	O
hardware	B-Architecture
to	O
a	O
computer	O
.	O
</s>
<s>
Most	O
drive	B-Device
bays	I-Device
are	O
fixed	O
to	O
the	O
inside	O
of	O
a	O
case	O
,	O
but	O
some	O
can	O
be	O
removed	O
.	O
</s>
<s>
Over	O
the	O
years	O
since	O
the	O
introduction	O
of	O
the	O
IBM	B-Device
PC	I-Device
,	O
it	O
and	O
its	O
compatibles	O
have	O
had	O
many	O
form	O
factors	O
of	O
drive	B-Device
bays	I-Device
.	O
</s>
<s>
Four	O
form	O
factors	O
are	O
in	O
common	O
use	O
today	O
,	O
the	O
5.25-inch	O
,	O
3.5-inch	O
,	O
2.5-inch	O
or	O
1.8-inch	O
drive	B-Device
bays	I-Device
.	O
</s>
<s>
These	O
names	O
do	O
not	O
refer	O
to	O
the	O
width	O
of	O
the	O
bay	O
itself	O
,	O
but	O
rather	O
to	O
the	O
width	O
of	O
the	O
disks	B-Device
used	O
by	O
the	O
drives	O
mounted	O
in	O
these	O
bays	O
.	O
</s>
<s>
8.0-inch	O
drive	B-Device
bays	I-Device
were	O
found	O
in	O
early	O
IBM	O
computers	O
,	O
CP/M	B-Application
computers	O
,	O
and	O
the	O
TRS-80	B-Device
Model	I-Device
II	I-Device
.	O
</s>
<s>
They	O
were	O
high	O
,	O
wide	O
,	O
and	O
approximately	O
deep	O
,	O
and	O
were	O
used	O
for	O
hard	B-Device
disk	I-Device
drives	I-Device
and	O
floppy	B-Device
disk	I-Device
drives	I-Device
.	O
</s>
<s>
5.25-inch	O
drive	B-Device
bays	I-Device
are	O
divided	O
into	O
two	O
height	O
specifications	O
,	O
full-height	B-Device
and	O
half-height	B-Device
.	O
</s>
<s>
Full-height	B-Device
bays	O
were	O
found	O
in	O
old	O
PCs	O
in	O
the	O
early	O
to	O
mid-1980s	O
.	O
</s>
<s>
They	O
were	O
high	O
,	O
wide	O
,	O
and	O
up	O
to	O
deep	O
,	O
used	O
mainly	O
for	O
hard	B-Device
disk	I-Device
drives	I-Device
and	O
floppy	B-Device
disk	I-Device
drives	I-Device
.	O
</s>
<s>
The	O
difference	O
between	O
those	O
widths	O
and	O
the	O
name	O
of	O
the	O
bay	O
size	O
is	O
because	O
it	O
is	O
named	O
after	O
the	O
size	O
of	O
floppy	B-Device
that	O
would	O
fit	O
in	O
those	O
drives	O
,	O
a	O
5.25-inch-wide	O
square	O
.	O
</s>
<s>
Half-height	B-Device
drive	B-Device
bays	I-Device
are	O
high	O
by	O
wide	O
,	O
and	O
are	O
the	O
standard	O
housing	O
for	O
CD	O
and	O
DVD	O
drives	O
in	O
modern	O
computers	O
.	O
</s>
<s>
They	O
were	O
sometimes	O
used	O
for	O
other	O
things	O
in	O
the	O
past	O
,	O
including	O
hard	B-Device
disk	I-Device
drives	I-Device
(	O
roughly	O
between	O
10	O
and	O
100	O
MB	O
)	O
and	O
floppy	B-Device
disk	I-Device
drives	I-Device
.	O
</s>
<s>
As	O
the	O
name	O
indicates	O
,	O
two	O
half-height	B-Device
devices	O
can	O
fit	O
in	O
one	O
full-height	B-Device
bay	O
.	O
</s>
<s>
Often	O
represented	O
as	O
5.25-inch	O
,	O
these	O
floppy	B-Device
disk	I-Device
drives	I-Device
are	O
obsolete	O
.	O
</s>
<s>
The	O
dimensions	O
of	O
a	O
5.25-inch	O
floppy	B-Device
drive	I-Device
are	O
specified	O
in	O
the	O
SFF	O
standard	O
specifications	O
which	O
were	O
incorporated	O
into	O
the	O
EIA-741	O
"	O
Specification	O
for	O
Small	O
Form	O
Factor	O
133.35	O
mm	O
(	O
5.25	O
in	O
)	O
Disk	B-Device
Drives	I-Device
"	O
by	O
the	O
Electronic	O
Industries	O
Association	O
(	O
EIA	O
)	O
.	O
</s>
<s>
3.5-inch	O
bays	O
,	O
like	O
their	O
larger	O
counterparts	O
,	O
are	O
named	O
after	O
diskette	B-Device
dimensions	O
;	O
their	O
actual	O
dimensions	O
are	O
wide	O
by	O
high	O
.	O
</s>
<s>
Those	O
with	O
an	O
opening	O
in	O
the	O
front	O
of	O
the	O
case	O
are	O
generally	O
used	O
for	O
floppy	B-Device
or	O
Zip	B-Operating_System
drives	I-Operating_System
.	O
</s>
<s>
Hard	B-Device
drives	I-Device
in	O
modern	O
computers	O
are	O
typically	O
mounted	O
in	O
fully	O
internal	O
4″	O
(	O
nominally	O
3.5	O
″	O
)	O
bays	O
.	O
</s>
<s>
Most	O
modern	O
computers	O
do	O
not	O
come	O
with	O
a	O
floppy	B-Device
drive	I-Device
at	O
all	O
,	O
and	O
may	O
lack	O
any	O
externally	O
accessible	O
3.5	O
″	O
bays	O
.	O
</s>
<s>
More	O
recently	O
,	O
it	O
is	O
becoming	O
common	O
to	O
use	O
3.5	O
″	O
bays	O
for	O
smart	O
card	O
and	O
memory	B-Device
card	I-Device
readers	O
,	O
or	O
for	O
panels	O
with	O
additional	O
USB	B-Protocol
ports	I-Protocol
.	O
</s>
<s>
However	O
,	O
most	O
laptops	O
have	O
drive	B-Device
bays	I-Device
smaller	O
than	O
the	O
15mm	O
specification	O
.	O
</s>
<s>
2.5-inch	O
hard	B-Device
drives	I-Device
may	O
range	O
from	O
7mm	O
to	O
15mm	O
in	O
height	O
,	O
there	O
are	O
two	O
sizes	O
that	O
appear	O
to	O
be	O
prominent	O
.	O
</s>
<s>
Many	O
laptop	O
drive	B-Device
bays	I-Device
are	O
designed	O
to	O
be	O
removable	O
trays	O
in	O
which	O
the	O
drives	O
are	O
mounted	O
,	O
to	O
ease	O
removal	O
and	O
replacement	O
.	O
</s>
<s>
Drive	B-Device
bays	I-Device
are	O
most	O
commonly	O
used	O
to	O
store	O
disk	B-Device
drives	I-Device
,	O
although	O
they	O
can	O
also	O
be	O
used	O
for	O
front-end	O
USB	B-Protocol
ports	I-Protocol
,	O
I/O	O
bays	O
,	O
card	B-Device
readers	I-Device
,	O
fans	B-Application
,	O
fan	O
controllers	O
,	O
RAID	B-Architecture
controllers	O
,	O
tool	O
storage	O
,	O
and	O
other	O
uses	O
.	O
</s>
<s>
Some	O
computers	O
have	O
a	O
small	O
system	B-Application
monitor	I-Application
LCD	O
mounted	O
in	O
a	O
drive	B-Device
bay	I-Device
.	O
</s>
<s>
The	O
drive	B-Device
bay	I-Device
is	O
usually	O
just	O
big	O
enough	O
for	O
the	O
drive	O
to	O
fit	O
inside	O
.	O
</s>
<s>
Since	O
computers	O
have	O
12V	O
rails	O
on	O
their	O
motherboards	O
,	O
some	O
computer	O
hobbyist	O
websites	O
even	O
sell	O
addons	O
for	O
cigarette	O
lighter	O
receptacles	O
to	O
power	O
or	O
recharge	O
devices	O
made	O
to	O
draw	O
power	O
from	O
automobiles	O
,	O
though	O
USB	B-Protocol
is	O
already	O
available	O
for	O
charging	O
devices	O
like	O
cell	O
phones	O
and	O
portable	O
media	O
players	O
.	O
</s>
