<s>
A	O
magneto-optical	B-Device
drive	I-Device
is	O
a	O
kind	O
of	O
optical	O
disc	O
drive	O
capable	O
of	O
writing	O
and	O
rewriting	O
data	O
upon	O
a	O
magneto-optical	B-Device
disc	I-Device
.	O
</s>
<s>
Although	O
optical	O
,	O
they	O
normally	O
appear	O
as	O
hard	B-Device
disk	I-Device
drives	I-Device
to	O
an	O
operating	B-General_Concept
system	I-General_Concept
and	O
can	O
be	O
formatted	O
with	O
any	O
file	B-Application
system	I-Application
.	O
</s>
<s>
Magneto-optical	B-Device
drives	I-Device
were	O
common	O
in	O
some	O
countries	O
,	O
such	O
as	O
Japan	O
,	O
but	O
have	O
fallen	O
into	O
disuse	O
.	O
</s>
<s>
Early	O
drives	O
are	O
130mm	O
and	O
have	O
the	O
size	O
of	O
full-height	O
130mm	O
hard-drives	B-Device
(	O
like	O
in	O
the	O
IBM	B-Device
PC	I-Device
XT	I-Device
)	O
.	O
</s>
<s>
130mm	O
media	O
looks	O
similar	O
to	O
a	O
CD-ROM	O
enclosed	O
in	O
an	O
old-style	O
caddy	O
,	O
while	O
90mm	O
media	O
is	O
about	O
the	O
size	O
of	O
a	O
regular	O
3-inch	O
floppy	B-Device
disk	I-Device
,	O
but	O
twice	O
the	O
thickness	O
.	O
</s>
<s>
Original	O
MO	O
systems	O
were	O
WORM	B-Device
(	O
write	B-Device
once	I-Device
,	I-Device
read	I-Device
many	I-Device
)	O
,	O
and	O
later	O
systems	O
were	O
read/write	O
.	O
</s>
<s>
The	O
only	O
physical	O
contact	O
is	O
during	O
recording	O
when	O
a	O
magnetic	O
head	O
is	O
brought	O
into	O
contact	O
with	O
the	O
side	O
of	O
the	O
disc	O
opposite	O
to	O
the	O
laser	O
,	O
similar	O
to	O
Floptical	B-Device
drives	I-Device
,	O
but	O
not	O
the	O
same	O
.	O
</s>
<s>
By	O
default	O
,	O
magneto-optical	B-Device
drives	I-Device
verify	O
information	O
after	O
writing	O
it	O
to	O
the	O
disc	O
,	O
and	O
are	O
able	O
to	O
immediately	O
report	O
any	O
problems	O
to	O
the	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Using	O
a	O
magneto-optical	B-Device
disc	I-Device
is	O
much	O
more	O
like	O
using	O
a	O
diskette	B-Device
drive	I-Device
than	O
a	O
CD-RW	O
drive	O
.	O
</s>
<s>
The	O
130mm	O
drives	O
were	O
always	O
SCSI	B-Architecture
.	O
</s>
<s>
The	O
90mm	O
drives	O
were	O
produced	O
in	O
SCSI	B-Architecture
,	O
IDE	O
,	O
and	O
USB	O
formats	O
.	O
</s>
<s>
A	O
self-contained	O
unit	O
holding	O
16	O
or	O
more	O
disks	O
and	O
connected	O
by	O
SCSI	B-Architecture
to	O
a	O
host	O
computer	O
,	O
the	O
library	O
required	O
specialized	O
archival	O
software	O
to	O
store	O
indices	O
of	O
data	O
,	O
and	O
select	O
disks	O
.	O
</s>
<s>
Light	O
Intensity	O
Modulated	O
Direct	O
OverWrite	O
(	O
LIMDOW	B-Device
)	O
technology	O
used	O
a	O
different	O
write	O
technology	O
,	O
which	O
improved	O
on	O
the	O
performance	O
levels	O
of	O
earlier	O
magneto-optical	B-Device
devices	O
.	O
</s>
<s>
LIMDOW	B-Device
disks	O
and	O
drives	O
worked	O
on	O
the	O
same	O
basic	O
principle	O
as	O
a	O
standard	O
magneto-optical	B-Device
drive	I-Device
:	O
the	O
write	O
surface	O
is	O
heated	O
up	O
and	O
took	O
on	O
a	O
magnetic	O
force	O
applied	O
from	O
outside	O
.	O
</s>
<s>
The	O
LIMDOW	B-Device
disk	O
has	O
two	O
magnetic	O
layers	O
just	O
behind	O
the	O
reflective	O
writing	O
surface	O
.	O
</s>
<s>
To	O
write	O
the	O
data	O
onto	O
the	O
disk	O
,	O
the	O
magneto-optical	B-Device
drive	I-Device
's	O
laser	O
pulses	O
between	O
two	O
powers	O
.	O
</s>
<s>
Thus	O
,	O
with	O
LIMDOW	B-Device
the	O
magneto-optical	B-Device
write	O
process	O
has	O
a	O
single	O
stage	O
,	O
improving	O
write	O
times	O
.	O
</s>
<s>
In	O
the	O
spring	O
of	O
1997	O
Plasmon	O
launched	O
its	O
DW260	O
drive	O
,	O
which	O
used	O
LIMDOW	B-Device
technology	I-Device
for	O
a	O
higher	O
level	O
of	O
performance	O
than	O
previous	O
magneto-optical	B-Device
drives	I-Device
.	O
</s>
<s>
LIMDOW	B-Device
drives	O
that	O
shipped	O
in	O
the	O
second	O
half	O
of	O
1997	O
has	O
search	O
speeds	O
of	O
less	O
than	O
15	O
ms	O
and	O
data	O
transfer	O
rates	O
in	O
excess	O
of	O
4	O
Mbit/s	O
,	O
which	O
are	O
fast	O
enough	O
for	O
storing	O
audio	O
and	O
streaming	O
MPEG-2	B-Algorithm
video	O
.	O
</s>
<s>
Magneto-optical	B-Device
drives	I-Device
were	O
first	O
offered	O
in	O
NeXT	O
computers	O
.	O
</s>
<s>
Sony	O
MiniDiscs	O
are	O
magneto-optical	B-Device
,	O
and	O
Sony	O
produces	O
many	O
other	O
formats	O
of	O
magneto-optical	B-Device
media	O
.	O
</s>
<s>
Pinnacle	O
Micro	O
was	O
a	O
major	O
manufacturer	O
of	O
magneto-optical	B-Device
drives	I-Device
.	O
</s>
<s>
3.5	B-Device
"	I-Device
drives	O
were	O
128MB	O
and	O
230MB	O
.	O
</s>
<s>
5.25	B-Device
"	I-Device
drives	O
produced	O
were	O
650MB	O
and	O
1.3GB	O
(	O
Sierra	O
)	O
,	O
2.6GB	O
(	O
Vertex	O
)	O
and	O
4.6GB	O
(	O
Apex	O
)	O
.	O
</s>
<s>
LMSI	O
produced	O
5.25	B-Device
"	I-Device
magneto-optical	B-Device
drives	I-Device
as	O
well	O
.	O
</s>
<s>
Maxoptix	O
,	O
a	O
spin-off	O
of	O
Maxtor	O
Corp.	O
,	O
was	O
a	O
major	O
manufacturer	O
of	O
130mm	O
or	O
5.25	B-Device
"	I-Device
magneto-optical	B-Device
drives	I-Device
.	O
</s>
<s>
A	O
current	O
model	O
is	O
the	O
T7-9100	O
drive	O
,	O
which	O
has	O
a	O
maximum	O
capacity	O
of	O
9.1GB	O
and	O
is	O
downward	O
read	O
and	O
write	O
compatible	O
with	O
5.2GB	O
,	O
4.8GB	O
,	O
4.1GB	O
,	O
2.6GB	O
,	O
and	O
2.3GB	O
magneto-optical	B-Device
disks	I-Device
,	O
and	O
read	O
compatible	O
with	O
1.3GB	O
,	O
1.2GB	O
,	O
650MB	O
,	O
and	O
600MB	O
magneto-optical	B-Device
disks	I-Device
.	O
</s>
<s>
Popular	O
older	O
models	O
of	O
5.25	B-Device
"	I-Device
Maxoptix	O
MO	B-Device
drives	I-Device
are	O
the	O
T6	O
Star	O
,	O
T6-5200	O
and	O
T5-2600	O
MO	B-Device
drives	I-Device
.	O
</s>
<s>
Fujitsu	O
was	O
a	O
major	O
manufacturer	O
of	O
90mm	O
magneto-optical	B-Device
drives	I-Device
,	O
exceeding	O
2GB	O
in	O
capacity	O
,	O
but	O
they	O
have	O
discontinued	O
production	O
and	O
sale	O
of	O
this	O
product	O
category	O
.	O
</s>
<s>
PDO	O
Konica	O
Minolta	O
was	O
the	O
last	O
manufacturer	O
of	O
90mm	O
3.5	B-Device
"	I-Device
magneto-optical	B-Device
drives	I-Device
.	O
</s>
<s>
They	O
had	O
a	O
3.5	B-Device
"	I-Device
1.3GB	O
USB	O
external	O
pocket	O
drive	O
available	O
for	O
sale	O
in	O
the	O
United	O
States	O
and	O
Europe	O
.	O
</s>
<s>
Magneto-optical	B-Device
drives	I-Device
are	O
not	O
Floptical	B-Device
drives	I-Device
,	O
which	O
likewise	O
combine	O
ferromagnetic	O
and	O
optical	O
technologies	O
,	O
albeit	O
in	O
a	O
different	O
manner	O
.	O
</s>
<s>
Flopticals	B-Device
are	O
21	O
megabyte	O
3.5	B-Device
"	I-Device
magnetic	O
diskettes	B-Device
using	O
optical	O
tracks	O
to	O
increase	O
the	O
tracking	O
precision	O
of	O
the	O
magnetic	O
head	O
,	O
from	O
the	O
usual	O
135	O
tracks	O
per	O
inch	O
to	O
1,250	O
tracks	O
per	O
inch	O
.	O
</s>
<s>
The	O
drives	O
can	O
also	O
read	O
and	O
write	O
traditional	O
3.5	B-Device
"	I-Device
diskettes	B-Device
,	O
although	O
not	O
the	O
2.88	O
megabyte	O
variety	O
.	O
</s>
<s>
Flopticals	B-Device
were	O
manufactured	O
by	O
Insite	O
Peripherals	O
,	O
a	O
company	O
founded	O
by	O
Jim	O
Burke	O
.	O
</s>
<s>
Magneto-optical	B-Device
disks	I-Device
in	O
particular	O
were	O
expensive	O
when	O
new	O
,	O
with	O
high	O
reliability	O
but	O
slow	O
writing	O
.	O
</s>
<s>
Magnetic	O
tape	O
formats	O
like	O
LTO	B-Operating_System
have	O
far	O
surpassed	O
MO	O
media	O
for	O
high	O
capacity	O
enterprise-grade	O
backup	O
storage	O
.	O
</s>
