<s>
IEEE	B-Protocol
1394	I-Protocol
is	O
an	O
interface	O
standard	O
for	O
a	O
serial	B-Protocol
bus	I-Protocol
for	O
high-speed	O
communications	O
and	O
isochronous	O
real-time	O
data	O
transfer	O
.	O
</s>
<s>
Apple	O
called	O
the	O
interface	O
FireWire	B-Protocol
.	O
</s>
<s>
It	O
is	O
also	O
known	O
by	O
the	O
brand	O
names	O
i.LINK	B-Protocol
(	O
Sony	O
)	O
,	O
and	O
Lynx	O
(	O
Texas	O
Instruments	O
)	O
.	O
</s>
<s>
FireWire	B-Protocol
is	O
also	O
available	O
in	O
Cat	B-Protocol
5	I-Protocol
and	O
optical	B-Architecture
fiber	I-Architecture
versions	O
.	O
</s>
<s>
The	O
1394	O
interface	O
is	O
comparable	O
to	O
USB	B-Protocol
.	O
</s>
<s>
USB	B-Protocol
was	O
developed	O
subsequently	O
and	O
gained	O
much	O
greater	O
market	O
share	O
.	O
</s>
<s>
USB	B-Protocol
requires	O
a	O
host	O
controller	O
whereas	O
IEEE	B-Protocol
1394	I-Protocol
is	O
cooperatively	O
managed	O
by	O
the	O
connected	O
devices	O
.	O
</s>
<s>
FireWire	B-Protocol
is	O
Apple	O
's	O
name	O
for	O
the	O
IEEE	B-Protocol
1394	I-Protocol
High	O
Speed	O
Serial	B-Protocol
Bus	I-Protocol
.	O
</s>
<s>
Its	O
development	O
was	O
initiated	O
by	O
Apple	O
in	O
1986	O
,	O
and	O
developed	O
by	O
the	O
IEEE	B-Protocol
P1394	I-Protocol
Working	O
Group	O
,	O
largely	O
driven	O
by	O
contributions	O
from	O
Sony	O
(	O
102	O
patents	O
)	O
,	O
Apple	O
(	O
58	O
patents	O
)	O
,	O
and	O
Panasonic	O
(	O
46	O
patents	O
)	O
,	O
in	O
addition	O
to	O
contributions	O
made	O
by	O
engineers	O
from	O
Philips	O
,	O
LG	O
Electronics	O
,	O
Toshiba	O
,	O
Hitachi	O
,	O
Canon	O
,	O
INMOS/SGS	O
Thomson	O
(	O
now	O
STMicroelectronics	O
)	O
,	O
and	O
Texas	O
Instruments	O
.	O
</s>
<s>
IEEE	B-Protocol
1394	I-Protocol
is	O
a	O
serial	B-Protocol
bus	I-Protocol
architecture	O
for	O
high-speed	O
data	O
transfer	O
.	O
</s>
<s>
FireWire	B-Protocol
is	O
a	O
serial	B-Protocol
bus	I-Protocol
,	O
meaning	O
that	O
information	O
is	O
transferred	O
one	O
bit	O
at	O
a	O
time	O
.	O
</s>
<s>
IEEE	B-Protocol
1394	I-Protocol
fully	O
supports	O
both	O
isochronous	O
and	O
asynchronous	B-Operating_System
applications	O
.	O
</s>
<s>
Apple	O
intended	O
FireWire	B-Protocol
to	O
be	O
a	O
serial	B-Protocol
replacement	O
for	O
the	O
parallel	O
SCSI	B-Architecture
bus	B-General_Concept
,	O
while	O
providing	O
connectivity	O
for	O
digital	O
audio	O
and	O
video	O
equipment	O
.	O
</s>
<s>
In	O
2007	O
,	O
IEEE	B-Protocol
1394	I-Protocol
was	O
a	O
composite	O
of	O
four	O
documents	O
:	O
the	O
original	O
IEEE	O
Std	O
.	O
</s>
<s>
1394a-2000	O
amendment	O
,	O
the	O
IEEE	O
Std	O
.	O
</s>
<s>
1394b-2002	O
amendment	O
,	O
and	O
the	O
IEEE	O
Std	O
.	O
</s>
<s>
Apple	O
first	O
included	O
onboard	O
FireWire	B-Protocol
in	O
some	O
of	O
its	O
1999	O
Macintosh	O
models	O
(	O
though	O
it	O
had	O
been	O
a	O
build-to-order	O
option	O
on	O
some	O
models	O
since	O
1997	O
)	O
,	O
and	O
most	O
Apple	O
Macintosh	O
computers	O
manufactured	O
in	O
the	O
years	O
2000	O
through	O
2011	O
included	O
FireWire	B-Protocol
ports	I-Protocol
.	O
</s>
<s>
However	O
,	O
in	O
February	O
2011	O
Apple	O
introduced	O
the	O
first	O
commercially	O
available	O
computer	O
with	O
Thunderbolt	B-Protocol
.	O
</s>
<s>
Apple	O
released	O
its	O
last	O
computers	O
with	O
FireWire	B-Protocol
in	O
2012	O
.	O
</s>
<s>
By	O
2014	O
,	O
Thunderbolt	B-Protocol
had	O
become	O
a	O
standard	O
feature	O
across	O
Apple	O
's	O
entire	O
line	O
of	O
computers	O
(	O
later	O
with	O
the	O
exception	O
of	O
the	O
12-inch	O
MacBook	O
introduced	O
in	O
2015	O
,	O
which	O
featured	O
only	O
a	O
sole	O
USB-C	O
port	O
)	O
effectively	O
becoming	O
the	O
spiritual	O
successor	O
to	O
FireWire	B-Protocol
in	O
the	O
Apple	O
ecosystem	O
.	O
</s>
<s>
Apple	O
's	O
last	O
products	O
with	O
FireWire	B-Protocol
,	O
the	O
Thunderbolt	B-Device
Display	I-Device
and	O
2012	O
13-inch	O
MacBook	B-Device
Pro	I-Device
,	O
were	O
discontinued	O
in	O
2016	O
.	O
</s>
<s>
Apple	O
still	O
sells	O
a	O
Thunderbolt	B-Protocol
to	O
FireWire	B-Protocol
Adapter	O
,	O
which	O
provides	O
one	O
FireWire	B-Protocol
800	O
port	O
.	O
</s>
<s>
A	O
separate	O
adapter	O
is	O
required	O
to	O
use	O
it	O
with	O
Thunderbolt	B-Protocol
3	O
.	O
</s>
<s>
Sony	O
's	O
implementation	O
of	O
the	O
system	O
,	O
i.LINK	B-Protocol
,	O
used	O
a	O
smaller	O
connector	O
with	O
only	O
four	O
signal	O
conductors	O
,	O
omitting	O
the	O
two	O
conductors	O
that	O
provide	O
power	O
for	O
devices	O
in	O
favor	O
of	O
a	O
separate	O
power	O
connector	O
.	O
</s>
<s>
This	O
style	O
was	O
later	O
added	O
into	O
the	O
1394a	B-Protocol
amendment	O
.	O
</s>
<s>
The	O
system	O
was	O
commonly	O
used	O
to	O
connect	O
data	B-General_Concept
storage	I-General_Concept
devices	I-General_Concept
and	O
DV	O
(	O
digital	O
video	O
)	O
cameras	O
,	O
but	O
was	O
also	O
popular	O
in	O
industrial	O
systems	O
for	O
machine	B-General_Concept
vision	I-General_Concept
and	O
professional	O
audio	O
systems	O
.	O
</s>
<s>
Many	O
users	O
preferred	O
it	O
over	O
the	O
more	O
common	O
USB	B-Protocol
2.0	O
for	O
its	O
then	O
greater	O
effective	O
speed	O
and	O
power	O
distribution	O
capabilities	O
.	O
</s>
<s>
Benchmarks	O
show	O
that	O
the	O
sustained	O
data	O
transfer	O
rates	O
are	O
higher	O
for	O
FireWire	B-Protocol
than	O
for	O
USB	B-Protocol
2.0	O
,	O
but	O
lower	O
than	O
USB	B-Protocol
3.0	O
.	O
</s>
<s>
Results	O
are	O
marked	O
on	O
Apple	B-Operating_System
Mac	I-Operating_System
OS	I-Operating_System
X	I-Operating_System
but	O
more	O
varied	O
on	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
Implementation	O
of	O
IEEE	B-Protocol
1394	I-Protocol
is	O
said	O
to	O
require	O
use	O
of	O
261	O
issued	O
international	O
patents	O
held	O
by	O
ten	O
corporations	O
.	O
</s>
<s>
Companies	O
holding	O
IEEE	B-Protocol
1394	I-Protocol
IP	B-Protocol
formed	O
a	O
patent	O
pool	O
with	O
MPEG	O
LA	O
,	O
LLC	O
as	O
the	O
license	O
administrator	O
,	O
to	O
whom	O
they	O
licensed	O
patents	O
.	O
</s>
<s>
MPEG	O
LA	O
sublicenses	O
these	O
patents	O
to	O
providers	O
of	O
equipment	O
implementing	O
IEEE	B-Protocol
1394	I-Protocol
.	O
</s>
<s>
The	O
last	O
of	O
the	O
patents	O
,	O
MY	O
120654	O
by	O
Sony	O
,	O
expired	O
on	O
November	O
30	O
,	O
2020	O
.	O
,	O
the	O
following	O
are	O
patent	O
holders	O
of	O
the	O
IEEE	B-Protocol
1394	I-Protocol
standard	O
,	O
as	O
listed	O
in	O
the	O
patent	O
pool	O
managed	O
by	O
MPEG	O
LA	O
.	O
</s>
<s>
At	O
least	O
one	O
formerly	O
licensed	O
patent	O
is	O
known	O
to	O
have	O
been	O
removed	O
from	O
the	O
pool	O
,	O
and	O
other	O
hardware	O
patents	O
exist	O
that	O
reference	O
IEEE	B-Protocol
1394	I-Protocol
.	O
</s>
<s>
The	O
1394	O
High	B-Protocol
Performance	I-Protocol
Serial	I-Protocol
Bus	I-Protocol
Trade	O
Association	O
(	O
the	O
1394	O
TA	O
)	O
was	O
formed	O
to	O
aid	O
the	O
marketing	O
of	O
IEEE	B-Protocol
1394	I-Protocol
.	O
</s>
<s>
FireWire	B-Protocol
can	O
connect	O
up	O
to	O
63	O
peripherals	O
in	O
a	O
tree	O
or	O
daisy-chain	O
topology	B-Architecture
(	O
as	O
opposed	O
to	O
Parallel	O
SCSI	B-Architecture
's	O
electrical	B-General_Concept
bus	I-General_Concept
topology	B-Architecture
)	O
.	O
</s>
<s>
It	O
allows	O
peer-to-peer	O
device	O
communication	O
—	O
such	O
as	O
communication	O
between	O
a	O
scanner	O
and	O
a	O
printer	O
—	O
to	O
take	O
place	O
without	O
using	O
system	O
memory	O
or	O
the	O
CPU	B-General_Concept
.	O
</s>
<s>
FireWire	B-Protocol
also	O
supports	O
multiple	O
host	O
controllers	O
per	O
bus	B-General_Concept
.	O
</s>
<s>
It	O
is	O
designed	O
to	O
support	O
plug	B-Device
and	I-Device
play	I-Device
and	O
hot	B-Device
swapping	I-Device
.	O
</s>
<s>
The	O
copper	O
cable	O
it	O
uses	O
in	O
its	O
most	O
common	O
implementation	O
can	O
be	O
up	O
to	O
long	O
and	O
is	O
more	O
flexible	O
than	O
most	O
parallel	O
SCSI	B-Architecture
cables	O
.	O
</s>
<s>
FireWire	B-Protocol
devices	O
implement	O
the	O
ISO/IEC	O
13213	O
configuration	O
ROM	B-Device
model	O
for	O
device	O
configuration	O
and	O
identification	O
,	O
to	O
provide	O
plug-and-play	B-Device
capability	O
.	O
</s>
<s>
All	O
FireWire	B-Protocol
devices	O
are	O
identified	O
by	O
an	O
IEEE	O
EUI-64	O
unique	O
identifier	O
in	O
addition	O
to	O
well-known	O
codes	O
indicating	O
the	O
type	O
of	O
device	O
and	O
the	O
protocols	O
it	O
supports	O
.	O
</s>
<s>
FireWire	B-Protocol
devices	O
are	O
organized	O
at	O
the	O
bus	B-General_Concept
in	O
a	O
tree	O
topology	B-Architecture
.	O
</s>
<s>
The	O
self-IDs	O
are	O
assigned	O
during	O
the	O
self-ID	O
process	O
,	O
which	O
happens	O
after	O
each	O
bus	B-General_Concept
resets	O
.	O
</s>
<s>
The	O
order	O
in	O
which	O
the	O
self-IDs	O
are	O
assigned	O
is	O
equivalent	O
to	O
traversing	O
the	O
tree	O
depth-first	B-Algorithm
,	O
post-order	O
.	O
</s>
<s>
FireWire	B-Protocol
is	O
capable	O
of	O
safely	O
operating	O
critical	O
systems	O
due	O
to	O
the	O
way	O
multiple	O
devices	O
interact	O
with	O
the	O
bus	B-General_Concept
and	O
how	O
the	O
bus	B-General_Concept
allocates	O
bandwidth	O
to	O
the	O
devices	O
.	O
</s>
<s>
FireWire	B-Protocol
is	O
capable	O
of	O
both	O
asynchronous	B-Operating_System
and	O
isochronous	O
transfer	O
methods	O
at	O
once	O
.	O
</s>
<s>
In	O
an	O
aircraft	O
,	O
for	O
instance	O
,	O
isochronous	O
devices	O
include	O
control	O
of	O
the	O
rudder	B-Protocol
,	O
mouse	O
operations	O
and	O
data	O
from	O
pressure	O
sensors	O
outside	O
the	O
aircraft	O
.	O
</s>
<s>
To	O
support	O
both	O
elements	O
,	O
FireWire	B-Protocol
dedicates	O
a	O
certain	O
percentage	O
to	O
isochronous	O
data	O
and	O
the	O
rest	O
to	O
asynchronous	B-Operating_System
data	O
.	O
</s>
<s>
In	O
IEEE	B-Protocol
1394	I-Protocol
,	O
80%	O
of	O
the	O
bus	B-General_Concept
is	O
reserved	O
for	O
isochronous	O
cycles	O
,	O
leaving	O
asynchronous	B-Operating_System
data	O
with	O
a	O
minimum	O
of	O
20%	O
of	O
the	O
bus	B-General_Concept
.	O
</s>
<s>
FireWire	B-Protocol
uses	O
Data/Strobe	B-Protocol
encoding	I-Protocol
(	O
D/S	O
encoding	O
)	O
.	O
</s>
<s>
In	O
D/S	O
encoding	O
,	O
two	O
non-return-to-zero	B-Protocol
(	O
NRZ	O
)	O
signals	O
are	O
used	O
to	O
transmit	O
the	O
data	O
with	O
high	O
reliability	O
.	O
</s>
<s>
This	O
in	O
turn	O
acts	O
as	O
the	O
bus	B-General_Concept
's	O
phase-locked	O
loop	O
for	O
synchronization	O
purposes	O
.	O
</s>
<s>
The	O
process	O
of	O
the	O
bus	B-General_Concept
deciding	O
which	O
node	O
gets	O
to	O
transmit	O
data	O
at	O
what	O
time	O
is	O
known	O
as	O
arbitration	B-Architecture
.	O
</s>
<s>
Each	O
arbitration	B-Architecture
round	O
lasts	O
about	O
125	O
microseconds	O
.	O
</s>
<s>
The	O
original	O
release	O
of	O
IEEE	O
1394-1995	O
specified	O
what	O
is	O
now	O
known	O
as	O
FireWire	B-Protocol
400	O
.	O
</s>
<s>
Cable	O
length	O
is	O
limited	O
to	O
,	O
although	O
up	O
to	O
16	O
cables	O
can	O
be	O
daisy	O
chained	O
using	O
active	O
repeaters	O
;	O
external	O
hubs	O
or	O
internal	O
hubs	O
are	O
often	O
present	O
in	O
FireWire	B-Protocol
equipment	O
.	O
</s>
<s>
An	O
amendment	O
,	O
IEEE	B-Protocol
1394a	I-Protocol
,	O
was	O
released	O
in	O
2000	O
,	O
which	O
clarified	O
and	O
improved	O
the	O
original	O
specification	O
.	O
</s>
<s>
It	O
added	O
support	O
for	O
asynchronous	B-Operating_System
streaming	O
,	O
quicker	O
bus	B-General_Concept
reconfiguration	O
,	O
packet	B-Protocol
concatenation	I-Protocol
,	O
and	O
a	O
power-saving	O
suspend	O
mode	O
.	O
</s>
<s>
IEEE	B-Protocol
1394a	I-Protocol
offers	O
a	O
couple	O
of	O
advantages	O
over	O
the	O
original	O
IEEE	B-Protocol
1394	I-Protocol
–	O
1995	O
.	O
</s>
<s>
1394a	B-Protocol
is	O
capable	O
of	O
arbitration	B-Architecture
accelerations	O
,	O
allowing	O
the	O
bus	B-General_Concept
to	O
accelerate	O
arbitration	B-Architecture
cycles	O
to	O
improve	O
efficiency	O
.	O
</s>
<s>
It	O
also	O
allows	O
for	O
arbitrated	O
short	O
bus	B-General_Concept
reset	O
,	O
in	O
which	O
a	O
node	O
can	O
be	O
added	O
or	O
dropped	O
without	O
causing	O
a	O
big	O
drop	O
in	O
isochronous	O
transmission	O
.	O
</s>
<s>
1394a	B-Protocol
also	O
standardized	O
the	O
4-conductor	O
alpha	O
connector	O
developed	O
by	O
Sony	O
and	O
trademarked	O
as	O
i.LINK	B-Protocol
,	O
already	O
widely	O
in	O
use	O
on	O
consumer	O
devices	O
such	O
as	O
camcorders	O
,	O
most	O
PC	O
laptops	O
,	O
a	O
number	O
of	O
PC	O
desktops	O
,	O
and	O
other	O
small	O
FireWire	B-Protocol
devices	O
.	O
</s>
<s>
IEEE	O
1394b-2002	O
introduced	O
FireWire	B-Protocol
800	O
(	O
Apple	O
's	O
name	O
for	O
the	O
9-conductor	O
S800	O
bilingual	O
version	O
of	O
the	O
IEEE	B-Protocol
1394b	I-Protocol
standard	O
)	O
.	O
</s>
<s>
It	O
is	O
backwards	O
compatible	O
with	O
the	O
slower	O
rates	O
and	O
6-conductor	O
alpha	O
connectors	O
of	O
FireWire	B-Protocol
400	O
.	O
</s>
<s>
However	O
,	O
while	O
the	O
IEEE	B-Protocol
1394a	I-Protocol
and	O
IEEE	B-Protocol
1394b	I-Protocol
standards	O
are	O
compatible	O
,	O
FireWire	B-Protocol
800	O
's	O
connector	O
,	O
referred	O
to	O
as	O
a	O
beta	O
connector	O
,	O
is	O
different	O
from	O
FireWire	B-Protocol
400	O
's	O
alpha	O
connectors	O
,	O
making	O
legacy	O
cables	O
incompatible	O
.	O
</s>
<s>
The	O
full	O
IEEE	B-Protocol
1394b	I-Protocol
specification	O
supports	O
data	O
rates	O
up	O
to	O
3200Mbit/s	O
(	O
i.e.	O
,	O
400	O
MB/s	O
)	O
over	O
beta-mode	O
or	O
optical	O
connections	O
up	O
to	O
in	O
length	O
.	O
</s>
<s>
Standard	O
Category	B-Protocol
5e	I-Protocol
unshielded	O
twisted	O
pair	O
supports	O
at	O
S100	O
.	O
</s>
<s>
The	O
original	O
1394	O
and	O
1394a	B-Protocol
standards	O
used	O
data/strobe	O
(	O
D/S	O
)	O
encoding	O
(	O
renamed	O
to	O
alpha	O
mode	O
)	O
with	O
the	O
cables	O
,	O
while	O
1394b	B-Protocol
added	O
a	O
data	O
encoding	O
scheme	O
called	O
8b/10b	B-Protocol
referred	O
to	O
as	O
beta	O
mode	O
.	O
</s>
<s>
Beta	O
mode	O
is	O
based	O
on	O
8b/10b	B-Protocol
(	O
from	O
Gigabit	O
Ethernet	O
,	O
also	O
used	O
for	O
many	O
other	O
protocols	O
)	O
.	O
</s>
<s>
8b/10b	B-Protocol
encoding	I-Protocol
involves	O
expanding	O
an	O
8-bit	O
data	O
word	O
into	O
10	O
bits	O
,	O
with	O
the	O
extra	O
bits	O
after	O
the	O
5th	O
and	O
8th	O
data	O
bits	O
.	O
</s>
<s>
An	O
additional	O
function	O
of	O
the	O
coding	O
scheme	O
is	O
to	O
support	O
the	O
arbitration	B-Architecture
for	O
bus	B-General_Concept
access	O
and	O
general	O
bus	B-General_Concept
control	O
.	O
</s>
<s>
This	O
is	O
possible	O
due	O
to	O
the	O
surplus	O
symbols	O
afforded	O
by	O
the	O
8b/10b	B-Protocol
expansion	O
.	O
</s>
<s>
It	O
provided	O
a	O
major	O
technical	O
improvement	O
,	O
namely	O
new	O
port	O
specification	O
that	O
provides	O
800	O
Mbit/s	O
over	O
the	O
same	O
8P8C	O
(	O
Ethernet	O
)	O
connectors	O
with	O
Category	B-Protocol
5e	I-Protocol
cable	I-Protocol
,	O
which	O
is	O
specified	O
in	O
IEEE	O
802.3	O
clause	O
40	O
(	O
gigabit	O
Ethernet	O
over	O
copper	O
twisted	O
pair	O
)	O
along	O
with	O
a	O
corresponding	O
automatic	O
negotiation	O
that	O
allows	O
the	O
same	O
port	O
to	O
connect	O
to	O
either	O
IEEE	O
Std	O
1394	O
or	O
IEEE	O
802.3	O
(	O
Ethernet	O
)	O
devices	O
.	O
</s>
<s>
Though	O
the	O
potential	O
for	O
a	O
combined	O
Ethernet	O
and	O
FireWire	B-Protocol
8P8C	O
port	O
is	O
intriguing	O
,	O
,	O
no	O
products	O
or	O
chipsets	O
include	O
this	O
capability	O
.	O
</s>
<s>
In	O
December	O
2007	O
,	O
the	O
1394	O
Trade	O
Association	O
announced	O
that	O
products	O
would	O
be	O
available	O
before	O
the	O
end	O
of	O
2008	O
using	O
the	O
S1600	O
and	O
S3200	O
modes	O
that	O
,	O
for	O
the	O
most	O
part	O
,	O
had	O
already	O
been	O
defined	O
in	O
1394b	B-Protocol
and	O
were	O
further	O
clarified	O
in	O
IEEE	O
Std	O
.	O
</s>
<s>
The	O
1.572864Gbit/s	O
and	O
3.145728Gbit/s	O
devices	O
use	O
the	O
same	O
9-conductor	O
beta	O
connectors	O
as	O
the	O
existing	O
FireWire	B-Protocol
800	O
and	O
are	O
fully	O
compatible	O
with	O
existing	O
S400	O
and	O
S800	O
devices	O
.	O
</s>
<s>
It	O
competes	O
with	O
USB	B-Protocol
3.0	O
.	O
</s>
<s>
Steve	O
Jobs	O
declared	O
FireWire	B-Protocol
dead	O
in	O
2008	O
.	O
,	O
there	O
were	O
few	O
S1600	O
devices	O
released	O
,	O
with	O
a	O
Sony	O
camera	O
being	O
the	O
only	O
notable	O
user	O
.	O
</s>
<s>
A	O
project	O
named	O
IEEE	O
P1394d	O
was	O
formed	O
by	O
the	O
IEEE	O
on	O
March	O
9	O
,	O
2009	O
to	O
add	O
single	B-Device
mode	I-Device
fiber	I-Device
as	O
an	O
additional	O
transport	O
medium	O
to	O
FireWire	B-Protocol
.	O
</s>
<s>
Other	O
future	O
iterations	O
of	O
FireWire	B-Protocol
were	O
expected	O
to	O
increase	O
speed	O
to	O
6.4	O
Gbit/s	O
and	O
additional	O
connectors	O
such	O
as	O
the	O
small	O
multimedia	O
interface	O
.	O
</s>
<s>
Full	O
support	O
for	O
IEEE	B-Protocol
1394a	I-Protocol
and	O
1394b	B-Protocol
is	O
available	O
for	O
Microsoft	B-Application
Windows	I-Application
,	O
FreeBSD	B-Operating_System
,	O
Linux	B-Application
,	O
Apple	O
Mac	O
OS	O
8.6	O
through	O
Mac	B-Operating_System
OS	I-Operating_System
9	I-Operating_System
,	O
NetBSD	B-Device
,	O
and	O
Haiku	B-Language
.	O
</s>
<s>
In	O
Windows	B-Application
XP	I-Application
,	O
a	O
degradation	O
in	O
performance	O
of	O
1394	O
devices	O
may	O
have	O
occurred	O
with	O
installation	O
of	O
Service	O
Pack	O
2	O
.	O
</s>
<s>
Some	O
FireWire	B-Protocol
hardware	O
manufacturers	O
also	O
provide	O
custom	O
device	O
drivers	O
that	O
replace	O
the	O
Microsoft	O
OHCI	B-Protocol
host	O
adapter	O
driver	O
stack	O
,	O
enabling	O
S800-capable	O
devices	O
to	O
run	O
at	O
full	O
800	O
Mbit/s	O
transfer	O
rates	O
on	O
older	O
versions	O
of	O
Windows	O
(	O
XP	B-Application
SP2	O
w/o	O
Hotfix	O
885222	O
)	O
and	O
Windows	B-Application
Vista	I-Application
.	O
</s>
<s>
At	O
the	O
time	O
of	O
its	O
release	O
,	O
Microsoft	B-Application
Windows	I-Application
Vista	I-Application
supported	O
only	O
1394a	B-Protocol
,	O
with	O
assurances	O
that	O
1394b	B-Protocol
support	O
would	O
come	O
in	O
the	O
next	O
service	O
pack	O
.	O
</s>
<s>
Service	O
Pack	O
1	O
for	O
Microsoft	B-Application
Windows	I-Application
Vista	I-Application
has	O
since	O
been	O
released	O
,	O
however	O
the	O
addition	O
of	O
1394b	B-Protocol
support	O
is	O
not	O
mentioned	O
anywhere	O
in	O
the	O
release	O
documentation	O
.	O
</s>
<s>
The	O
1394	O
bus	B-General_Concept
driver	O
was	O
rewritten	O
for	O
Windows	B-Device
7	I-Device
to	O
provide	O
support	O
for	O
higher	O
speeds	O
and	O
alternative	O
media	O
.	O
</s>
<s>
In	O
Linux	B-Application
,	O
support	O
was	O
originally	O
provided	O
by	O
libraw1394	O
making	O
direct	O
communication	O
between	O
user	O
space	O
and	O
IEEE	B-Protocol
1394	I-Protocol
buses	O
.	O
</s>
<s>
Under	O
FCC	O
Code	O
47	O
CFR	O
76.640	O
section	O
4	O
,	O
subsections	O
1	O
and	O
2	O
,	O
Cable	O
TV	O
providers	O
(	O
in	O
the	O
US	O
,	O
with	O
digital	O
systems	O
)	O
must	O
,	O
upon	O
request	O
of	O
a	O
customer	O
,	O
have	O
provided	O
a	O
high-definition	O
capable	O
cable	O
box	O
with	O
a	O
functional	O
FireWire	B-Protocol
interface	O
.	O
</s>
<s>
In	O
June	O
2010	O
,	O
the	O
FCC	O
issued	O
an	O
order	O
that	O
permitted	O
set-top	O
boxes	O
to	O
include	O
IP-based	O
interfaces	O
in	O
place	O
of	O
FireWire	B-Protocol
.	O
</s>
<s>
While	O
both	O
technologies	O
provide	O
similar	O
end	O
results	O
,	O
there	O
are	O
fundamental	O
differences	O
between	O
USB	B-Protocol
and	O
FireWire	B-Protocol
.	O
</s>
<s>
USB	B-Protocol
requires	O
the	O
presence	O
of	O
a	O
host	O
controller	O
,	O
typically	O
a	O
PC	O
,	O
which	O
connects	O
point	O
to	O
point	O
with	O
the	O
USB	B-Protocol
device	I-Protocol
.	O
</s>
<s>
This	O
allows	O
for	O
simpler	O
(	O
and	O
lower-cost	O
)	O
peripherals	O
,	O
at	O
the	O
cost	O
of	O
lowered	O
functionality	O
of	O
the	O
bus	B-General_Concept
.	O
</s>
<s>
Intelligent	O
hubs	O
are	O
required	O
to	O
connect	O
multiple	O
USB	B-Protocol
devices	I-Protocol
to	O
a	O
single	O
USB	B-Protocol
host	O
controller	O
.	O
</s>
<s>
By	O
contrast	O
,	O
FireWire	B-Protocol
is	O
essentially	O
a	O
peer-to-peer	O
network	O
(	O
where	O
any	O
device	O
may	O
serve	O
as	O
the	O
host	O
or	O
client	O
)	O
,	O
allowing	O
multiple	O
devices	O
to	O
be	O
connected	O
on	O
one	O
bus	B-General_Concept
.	O
</s>
<s>
The	O
FireWire	B-Protocol
host	O
interface	O
supports	O
DMA	O
and	O
memory-mapped	O
devices	O
,	O
allowing	O
data	O
transfers	O
to	O
happen	O
without	O
loading	O
the	O
host	O
CPU	B-General_Concept
with	O
interrupts	O
and	O
buffer-copy	O
operations	O
.	O
</s>
<s>
Additionally	O
,	O
FireWire	B-Protocol
features	O
two	O
data	B-General_Concept
buses	I-General_Concept
for	O
each	O
segment	O
of	O
the	O
bus	B-General_Concept
network	O
,	O
whereas	O
,	O
until	O
USB	B-Protocol
3.0	O
,	O
USB	B-Protocol
featured	O
only	O
one	O
.	O
</s>
<s>
This	O
means	O
that	O
FireWire	B-Protocol
can	O
have	O
communication	O
in	O
both	O
directions	O
at	O
the	O
same	O
time	O
(	O
full-duplex	O
)	O
,	O
whereas	O
USB	B-Protocol
communication	O
prior	O
to	O
3.0	O
can	O
only	O
occur	O
in	O
one	O
direction	O
at	O
any	O
one	O
time	O
(	O
half-duplex	O
)	O
.	O
</s>
<s>
While	O
USB	B-Protocol
2.0	O
expanded	O
into	O
the	O
fully	O
backwards-compatible	O
USB	B-Protocol
3.0	O
and	O
3.1	O
(	O
using	O
the	O
same	O
main	O
connector	O
type	O
)	O
,	O
FireWire	B-Protocol
used	O
a	O
different	O
connector	O
between	O
400	O
and	O
800	O
implementations	O
.	O
</s>
<s>
IEEE	B-Protocol
1394	I-Protocol
was	O
the	O
High-Definition	O
Audio-Video	O
Network	O
Alliance	O
(	O
HANA	O
)	O
standard	O
connection	O
interface	O
for	O
A/V	O
(	O
audio/visual	O
)	O
component	O
communication	O
and	O
control	O
.	O
</s>
<s>
SAE	O
Aerospace	O
standard	O
AS5643	O
originally	O
released	O
in	O
2004	O
and	O
reaffirmed	O
in	O
2013	O
establishes	O
IEEE-1394	B-Protocol
standards	O
as	O
a	O
military	O
and	O
aerospace	O
databus	O
network	O
in	O
those	O
vehicles	O
.	O
</s>
<s>
AS5643	O
combines	O
existing	O
1394-2008	O
features	O
like	O
looped	O
topology	B-Architecture
with	O
additional	O
features	O
like	O
transformer	O
isolation	O
and	O
time	O
synchronization	O
,	O
to	O
create	O
deterministic	O
double	O
and	O
triple	O
fault-tolerant	O
data	B-General_Concept
bus	I-General_Concept
networks	O
.	O
</s>
<s>
FireWire	B-Protocol
can	O
be	O
used	O
for	O
ad	O
hoc	O
(	O
terminals	O
only	O
,	O
no	O
routers	O
except	O
where	O
a	O
FireWire	B-Protocol
hub	O
is	O
used	O
)	O
computer	B-Architecture
networks	I-Architecture
.	O
</s>
<s>
Specifically	O
,	O
RFC	O
2734	O
specifies	O
how	O
to	O
run	O
IPv4	B-Protocol
over	O
the	O
FireWire	B-Protocol
interface	O
,	O
and	O
RFC	O
3146	O
specifies	O
how	O
to	O
run	O
IPv6	B-Protocol
.	O
</s>
<s>
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
,	O
Linux	B-Application
,	O
and	O
FreeBSD	B-Operating_System
include	O
support	O
for	O
networking	O
over	O
FireWire	B-Protocol
.	O
</s>
<s>
Windows	B-Application
95	I-Application
,	O
Windows	B-Device
98	I-Device
,	O
Windows	B-Device
Me	I-Device
,	O
Windows	B-Application
XP	I-Application
and	O
Windows	B-Application
Server	I-Application
2003	I-Application
include	O
native	O
support	O
for	O
IEEE	B-Protocol
1394	I-Protocol
networking	O
.	O
</s>
<s>
Windows	B-Application
2000	I-Application
does	O
not	O
have	O
native	O
support	O
but	O
may	O
work	O
with	O
third	O
party	O
drivers	O
.	O
</s>
<s>
A	O
network	O
can	O
be	O
set	O
up	O
between	O
two	O
computers	O
using	O
a	O
single	O
standard	O
FireWire	B-Protocol
cable	O
,	O
or	O
by	O
multiple	O
computers	O
through	O
use	O
of	O
a	O
hub	O
.	O
</s>
<s>
This	O
is	O
similar	O
to	O
Ethernet	O
networks	O
with	O
the	O
major	O
differences	O
being	O
transfer	B-Device
speed	I-Device
,	O
conductor	O
length	O
,	O
and	O
the	O
fact	O
that	O
standard	O
FireWire	B-Protocol
cables	O
can	O
be	O
used	O
for	O
point-to-point	B-Architecture
communication	I-Architecture
.	O
</s>
<s>
On	O
December	O
4	O
,	O
2004	O
,	O
Microsoft	O
announced	O
that	O
it	O
would	O
discontinue	O
support	O
for	O
IP	B-Protocol
networking	O
over	O
the	O
FireWire	B-Protocol
interface	O
in	O
all	O
future	O
versions	O
of	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
Consequently	O
,	O
support	O
for	O
this	O
feature	O
is	O
absent	O
from	O
Windows	B-Application
Vista	I-Application
and	O
later	O
Windows	O
releases	O
.	O
</s>
<s>
Microsoft	O
rewrote	O
their	O
1394	O
driver	O
in	O
Windows	B-Device
7	I-Device
but	O
networking	O
support	O
for	O
FireWire	B-Protocol
is	O
not	O
present	O
.	O
</s>
<s>
Unibrain	O
offers	O
free	O
FireWire	B-Protocol
networking	O
drivers	O
for	O
Windows	O
called	O
ubCore	O
,	O
which	O
support	O
Windows	B-Application
Vista	I-Application
and	O
later	O
versions	O
.	O
</s>
<s>
Some	O
models	O
of	O
the	O
PlayStation	B-Device
2	I-Device
console	O
had	O
an	O
i.LINK-branded	O
1394	O
connector	O
.	O
</s>
<s>
IIDC	O
(	O
Instrumentation	O
&	O
Industrial	O
Digital	O
Camera	O
)	O
is	O
the	O
FireWire	B-Protocol
data	O
format	O
standard	O
for	O
live	O
video	O
,	O
and	O
is	O
used	O
by	O
Apple	O
's	O
iSight	B-Protocol
A/V	O
camera	O
.	O
</s>
<s>
The	O
system	O
was	O
designed	O
for	O
machine	B-General_Concept
vision	I-General_Concept
systems	O
but	O
is	O
also	O
used	O
for	O
other	O
computer	B-Application
vision	I-Application
applications	O
and	O
for	O
some	O
webcams	O
.	O
</s>
<s>
Although	O
they	O
are	O
easily	O
confused	O
since	O
they	O
both	O
run	O
over	O
FireWire	B-Protocol
,	O
IIDC	O
is	O
different	O
from	O
,	O
and	O
incompatible	O
with	O
,	O
the	O
ubiquitous	O
AV/C	O
(	O
Audio	O
Video	O
Control	O
)	O
used	O
to	O
control	O
camcorders	O
and	O
other	O
consumer	O
video	O
devices	O
.	O
</s>
<s>
All	O
DV	O
cameras	O
that	O
recorded	O
to	O
tape	O
media	O
had	O
a	O
FireWire	B-Protocol
interface	O
(	O
usually	O
a	O
4-conductor	O
)	O
.	O
</s>
<s>
All	O
DV	O
ports	O
on	O
camcorders	O
only	O
operate	O
at	O
the	O
slower	O
100	O
Mbit/s	O
speed	O
of	O
FireWire	B-Protocol
.	O
</s>
<s>
This	O
presents	O
operational	O
issues	O
if	O
the	O
camcorder	O
is	O
daisy	O
chained	O
from	O
a	O
faster	O
S400	O
device	O
or	O
via	O
a	O
common	O
hub	O
because	O
any	O
segment	O
of	O
a	O
FireWire	B-Protocol
network	O
cannot	O
support	O
multiple	O
speed	O
communication	O
.	O
</s>
<s>
Labeling	O
of	O
the	O
port	O
varied	O
by	O
manufacturer	O
,	O
with	O
Sony	O
using	O
either	O
its	O
i.LINK	B-Protocol
trademark	O
or	O
the	O
letters	O
DV	O
.	O
</s>
<s>
Many	O
digital	B-Application
video	I-Application
recorders	I-Application
have	O
a	O
DV-input	O
FireWire	B-Protocol
connector	O
(	O
usually	O
an	O
alpha	O
connector	O
)	O
that	O
can	O
be	O
used	O
to	O
record	O
video	O
directly	O
from	O
a	O
DV	O
camcorder	O
(	O
computer-free	O
)	O
.	O
</s>
<s>
USB	B-Protocol
is	O
unsuitable	O
for	O
the	O
transfer	O
of	O
the	O
video	O
data	O
from	O
tape	O
because	O
tape	O
by	O
its	O
very	O
nature	O
does	O
not	O
support	O
variable	O
data	O
rates	O
.	O
</s>
<s>
USB	B-Protocol
relies	O
heavily	O
on	O
processor	O
support	O
and	O
this	O
was	O
not	O
guaranteed	O
to	O
service	O
the	O
USB	B-Protocol
port	I-Protocol
in	O
time	O
.	O
</s>
<s>
The	O
later	O
move	O
away	O
from	O
tape	O
towards	O
solid-state	O
memory	O
or	O
disc	O
media	O
(	O
e.g.	O
,	O
SD	O
Cards	O
,	O
optical	O
disks	O
or	O
hard	O
drives	O
)	O
has	O
facilitated	O
moving	O
to	O
USB	B-Protocol
transfer	O
because	O
file-based	O
data	O
can	O
be	O
moved	O
in	O
segments	O
as	O
required	O
.	O
</s>
<s>
IEEE	B-Protocol
1394	I-Protocol
interface	I-Protocol
is	O
commonly	O
found	O
in	O
frame	B-Device
grabbers	I-Device
,	O
devices	O
that	O
capture	O
and	O
digitize	O
an	O
analog	O
video	O
signal	O
;	O
however	O
,	O
IEEE	B-Protocol
1394	I-Protocol
is	O
facing	O
competition	O
from	O
the	O
Gigabit	O
Ethernet	O
interface	O
(	O
citing	O
speed	O
and	O
availability	O
issues	O
)	O
.	O
</s>
<s>
iPods	B-Device
released	O
prior	O
to	O
the	B-Device
iPod	I-Device
with	O
Dock	B-Operating_System
Connector	I-Operating_System
used	O
IEEE	B-Protocol
1394a	I-Protocol
ports	O
for	O
transferring	O
music	O
files	O
and	O
charging	O
,	O
but	O
in	O
2003	O
,	O
the	O
FireWire	B-Protocol
port	I-Protocol
in	O
iPods	B-Device
was	O
succeeded	O
by	O
Apple	O
's	O
dock	B-Operating_System
connector	I-Operating_System
and	O
IEEE	B-Protocol
1394	I-Protocol
to	O
30-pin	O
connector	O
cables	O
were	O
made	O
.	O
</s>
<s>
Apple	O
Inc	O
.	O
dropped	O
support	O
for	O
FireWire	B-Protocol
cables	O
starting	O
with	O
iPod	B-Device
nano	I-Device
(	O
4th	O
Generation	O
)	O
,	O
iPod	B-Device
touch	I-Device
(	O
2nd	O
Generation	O
)	O
,	O
and	O
iPhone	B-Operating_System
in	O
favor	O
of	O
USB	B-Protocol
cables	O
.	O
</s>
<s>
Devices	O
on	O
a	O
FireWire	B-Protocol
bus	B-General_Concept
can	O
communicate	O
by	O
direct	B-General_Concept
memory	I-General_Concept
access	I-General_Concept
(	O
DMA	O
)	O
,	O
where	O
a	O
device	O
can	O
use	O
hardware	O
to	O
map	O
internal	O
memory	O
to	O
FireWire	B-Protocol
's	O
physical	O
memory	O
space	O
.	O
</s>
<s>
The	O
SBP-2	B-General_Concept
(	O
Serial	B-General_Concept
Bus	I-General_Concept
Protocol	I-General_Concept
2	I-General_Concept
)	O
used	O
by	O
FireWire	B-Protocol
disk	B-General_Concept
drives	I-General_Concept
uses	O
this	O
capability	O
to	O
minimize	O
interrupts	O
and	O
buffer	O
copies	O
.	O
</s>
<s>
In	O
SBP-2	B-General_Concept
,	O
the	O
initiator	O
(	O
controlling	O
device	O
)	O
sends	O
a	O
request	O
by	O
remotely	O
writing	O
a	O
command	O
into	O
a	O
specified	O
area	O
of	O
the	O
target	O
's	O
FireWire	B-Protocol
address	O
space	O
.	O
</s>
<s>
This	O
command	O
usually	O
includes	O
buffer	O
addresses	O
in	O
the	O
initiator	O
's	O
FireWire	B-Protocol
Physical	O
Address	O
Space	O
,	O
which	O
the	O
target	O
is	O
supposed	O
to	O
use	O
for	O
moving	O
I/O	O
data	O
to	O
and	O
from	O
the	O
initiator	O
.	O
</s>
<s>
On	O
many	O
implementations	O
,	O
particularly	O
those	O
like	O
PCs	O
and	O
Macs	O
using	O
the	O
popular	O
OHCI	B-Protocol
,	O
the	O
mapping	O
between	O
the	O
FireWire	B-Protocol
physical	O
memory	O
space	O
and	O
device	O
physical	O
memory	O
is	O
done	O
in	O
hardware	O
,	O
without	O
operating	O
system	O
intervention	O
.	O
</s>
<s>
While	O
this	O
enables	O
high-speed	O
and	O
low-latency	O
communication	O
between	O
data	O
sources	O
and	O
sinks	O
without	O
unnecessary	O
copying	O
(	O
such	O
as	O
between	O
a	O
video	O
camera	O
and	O
a	O
software	O
video	O
recording	O
application	O
,	O
or	O
between	O
a	O
disk	O
drive	O
and	O
the	O
application	O
buffers	O
)	O
,	O
this	O
can	O
also	O
be	O
a	O
security	O
or	O
media	O
rights-restriction	O
risk	O
if	O
untrustworthy	O
devices	O
are	O
attached	O
to	O
the	O
bus	B-General_Concept
and	O
initiate	O
a	O
DMA	O
attack	O
.	O
</s>
<s>
One	O
of	O
the	O
applications	O
known	O
to	O
exploit	O
this	O
to	O
gain	O
unauthorized	O
access	O
to	O
running	O
Windows	O
,	O
Mac	O
OS	O
and	O
Linux	B-Application
computers	O
is	O
the	O
spyware	O
FinFireWire	O
.	O
</s>
<s>
For	O
this	O
reason	O
,	O
high-security	O
installations	O
typically	O
either	O
use	O
newer	O
machines	O
that	O
map	O
a	O
virtual	B-Architecture
memory	I-Architecture
space	O
to	O
the	O
FireWire	B-Protocol
physical	O
memory	O
space	O
(	O
such	O
as	O
a	O
Power	B-Device
Mac	I-Device
G5	I-Device
,	O
or	O
any	O
Sun	O
workstation	O
)	O
,	O
disable	O
relevant	O
drivers	O
at	O
operating	O
system	O
level	O
,	O
disable	O
the	O
OHCI	B-Protocol
hardware	O
mapping	O
between	O
FireWire	B-Protocol
and	O
device	O
memory	O
,	O
physically	O
disable	O
the	O
entire	O
FireWire	B-Protocol
interface	O
,	O
or	O
opt	O
to	O
not	O
use	O
FireWire	B-Protocol
or	O
other	O
hardware	O
like	O
PCMCIA	B-Architecture
,	O
PC	B-Architecture
Card	I-Architecture
,	O
ExpressCard	B-Device
or	O
Thunderbolt	B-Protocol
,	O
which	O
expose	O
DMA	O
to	O
external	O
components	O
.	O
</s>
<s>
An	O
unsecured	O
FireWire	B-Protocol
interface	O
can	O
be	O
used	O
to	O
debug	B-Device
a	O
machine	O
whose	O
operating	O
system	O
has	O
crashed	O
,	O
and	O
in	O
some	O
systems	O
for	O
remote-console	O
operations	O
.	O
</s>
<s>
Windows	O
natively	O
supports	O
this	O
scenario	O
of	O
kernel	O
debugging	O
,	O
although	O
newer	O
Windows	B-Application
Insider	I-Application
Preview	O
builds	O
no	O
longer	O
include	O
the	O
ability	O
out	O
of	O
the	O
box	O
.	O
</s>
<s>
On	O
FreeBSD	B-Operating_System
,	O
the	O
dcons	O
driver	O
provides	O
both	O
,	O
using	O
gdb	B-Language
as	O
debugger	O
.	O
</s>
<s>
Under	O
Linux	B-Application
,	O
firescope	O
and	O
fireproxy	O
exist	O
.	O
</s>
