<s>
The	O
Checking	O
Integrated	O
Circuit	O
(	O
CIC	B-Device
)	O
is	O
a	O
lockout	O
chip	O
designed	O
by	O
Nintendo	O
for	O
the	O
Nintendo	O
Entertainment	O
System	O
(	O
NES	O
)	O
video	B-Device
game	I-Device
console	I-Device
in	O
1985	O
;	O
the	O
chip	O
is	O
part	O
of	O
a	O
system	O
known	O
as	O
10NES	O
,	O
in	O
which	O
a	O
'	O
key	O
 '	O
(	O
which	O
is	O
stored	O
in	O
the	O
game	O
)	O
is	O
used	O
by	O
the	O
'	O
lock	O
 '	O
(	O
stored	O
in	O
the	O
console	O
)	O
to	O
both	O
check	O
if	O
the	O
game	O
is	O
authentic	O
,	O
and	O
if	O
the	O
game	O
is	O
the	O
same	O
region	O
as	O
the	O
console	O
.	O
</s>
<s>
Improved	O
designs	O
of	O
the	O
CIC	B-Device
chip	O
were	O
also	O
used	O
in	O
the	O
later	O
Super	B-Application
Nintendo	I-Application
Entertainment	I-Application
System	I-Application
and	O
Nintendo	B-Operating_System
64	I-Operating_System
,	O
although	O
running	O
an	O
updated	O
security	O
program	O
which	O
performs	O
additional	O
checks	O
.	O
</s>
<s>
The	O
lockout	O
chip	O
was	O
controversial	O
,	O
with	O
several	O
developers	O
opting	O
to	O
release	O
their	O
games	O
without	O
Nintendo	O
's	O
approval	O
by	O
using	O
work-arounds	O
;	O
the	O
most	O
well-known	O
of	O
these	O
was	O
Tengen	O
(	O
a	O
subsidiary	O
of	O
Atari	O
)	O
,	O
which	O
copied	O
the	O
CIC	B-Device
chip	O
,	O
resulting	O
in	O
their	O
games	O
running	O
without	O
issue	O
.	O
</s>
<s>
The	O
10NES	O
system	O
is	O
a	O
lock-out	O
system	O
designed	O
for	O
the	O
North	O
American	O
and	O
European	O
versions	O
of	O
the	O
Nintendo	O
Entertainment	O
System	O
(	O
NES	O
)	O
video	B-Device
game	I-Device
console	I-Device
.	O
</s>
<s>
The	O
system	O
consists	O
of	O
two	O
parts	O
,	O
a	O
Sharp	O
Corporation	O
4-bit	O
SM590	O
microcontroller	B-Architecture
in	O
the	O
console	O
(	O
the	O
"	O
lock	O
"	O
)	O
that	O
checks	O
the	O
inserted	O
cartridge	O
for	O
authentication	O
,	O
and	O
a	O
matching	O
chip	O
in	O
the	O
game	O
cartridge	O
(	O
the	O
"	O
key	O
"	O
)	O
that	O
gives	O
the	O
code	O
upon	O
demand	O
.	O
</s>
<s>
If	O
the	O
cartridge	O
does	O
not	O
successfully	O
provide	O
the	O
authentication	O
,	O
then	O
the	O
CIC	B-Device
repeatedly	O
resets	O
the	O
CPU	B-Device
at	O
a	O
frequency	O
of	O
1Hz	O
.	O
</s>
<s>
The	O
program	O
used	O
in	O
the	O
NES	O
CIC	B-Device
is	O
called	O
10NES	O
and	O
was	O
patented	O
under	O
.	O
</s>
<s>
Some	O
unlicensed	O
companies	O
created	O
circuits	O
that	O
used	O
a	O
voltage	O
spike	O
to	O
shut	O
off	O
the	O
CIC	B-Device
before	O
it	O
can	O
perform	O
the	O
authentication	O
checks	O
.	O
</s>
<s>
A	O
few	O
unlicensed	O
games	O
released	O
in	O
Europe	O
and	O
Australia	O
(	O
such	O
as	O
HES	O
games	O
)	O
came	O
in	O
the	O
form	O
of	O
a	O
dongle	B-Device
that	O
would	O
be	O
connected	O
to	O
a	O
licensed	O
cartridge	O
,	O
in	O
order	O
to	O
use	O
that	O
cartridge	O
's	O
CIC	B-Device
lockout	O
chip	O
for	O
authentication	O
.	O
</s>
<s>
This	O
method	O
also	O
worked	O
on	O
the	O
SNES	B-Application
and	O
was	O
utilized	O
by	O
Super	B-Application
Noah	I-Application
’s	I-Application
Ark	I-Application
3D	I-Application
.	O
</s>
<s>
Since	O
then	O
,	O
there	O
have	O
been	O
a	O
few	O
other	O
open	O
source	O
implementations	O
to	O
allow	O
the	O
general	O
public	O
to	O
reproduce	O
multi-region	O
CICs	B-Device
on	O
AVR	O
microcontrollers	B-Architecture
.	O
</s>
<s>
Towards	O
the	O
end	O
of	O
the	O
SNES	B-Application
lifespan	O
,	O
the	O
CIC	B-Device
was	O
cloned	O
and	O
used	O
in	O
pirate	O
games	O
.	O
</s>
<s>
Often	O
,	O
the	O
clone	O
CIC	B-Device
chip	O
would	O
be	O
rebranded	O
with	O
an	O
inconspicuous	O
brand/part	O
number	O
to	O
prevent	O
detection	O
by	O
authorities	O
.	O
</s>
<s>
Alternatively	O
the	O
aforementioned	O
method	O
of	O
using	O
a	O
licensed	O
game	O
's	O
CIC	B-Device
chip	O
was	O
possible	O
,	O
as	O
it	O
was	O
used	O
in	O
the	O
SNES	B-Application
version	O
of	O
Super	B-Application
Noah	I-Application
’s	I-Application
Ark	I-Application
3D	I-Application
and	O
Hong	O
Kong	O
97	O
.	O
</s>
