<s>
Multi-memory	B-General_Concept
controllers	I-General_Concept
or	O
memory	B-General_Concept
management	I-General_Concept
controllers	I-General_Concept
(	O
MMC	O
)	O
are	O
different	O
kinds	O
of	O
special	O
chips	B-Architecture
designed	O
by	O
various	O
video	O
game	O
developers	O
for	O
use	O
in	O
Nintendo	O
Entertainment	O
System	O
(	O
NES	O
)	O
cartridges	B-Protocol
.	O
</s>
<s>
These	O
chips	B-Architecture
extend	O
the	O
capabilities	O
of	O
the	O
original	O
console	B-Device
and	O
make	O
it	O
possible	O
to	O
create	O
NES	O
games	O
with	O
features	O
the	O
original	O
console	B-Device
cannot	O
offer	O
alone	O
.	O
</s>
<s>
The	O
basic	O
NES	O
hardware	O
supports	O
only	O
40KB	O
of	O
ROM	B-Device
total	O
,	O
up	O
to	O
32KB	O
PRG	O
and	O
8KB	O
CHR	O
,	O
thus	O
only	O
a	O
single	O
tile	O
and	O
sprite	O
table	O
are	O
possible	O
.	O
</s>
<s>
This	O
limit	O
was	O
rapidly	O
reached	O
within	O
the	O
Famicom	O
's	O
first	O
two	O
years	O
on	O
the	O
market	O
and	O
game	O
developers	O
began	O
requesting	O
a	O
way	O
to	O
expand	O
the	O
console	B-Device
's	O
capabilities	O
.	O
</s>
<s>
In	O
the	O
emulation	O
community	O
these	O
chips	B-Architecture
are	O
also	O
known	O
as	O
mappers	O
.	O
</s>
<s>
CNROM	O
supports	O
a	O
single	O
fixed	O
PRG	O
bank	O
and	O
up	O
to	O
eight	O
CHR	O
banks	O
for	O
96KB	O
total	O
ROM	B-Device
.	O
</s>
<s>
Many	O
CNROM	O
games	O
store	O
the	O
game	O
level	O
data	O
in	O
the	O
CHR	O
ROM	B-Device
and	O
blank	O
the	O
screen	O
while	O
reading	O
it	O
.	O
</s>
<s>
Early	O
NES	O
mappers	O
are	O
composed	O
of	O
7400	O
series	O
discrete	O
logic	O
chips	B-Architecture
.	O
</s>
<s>
Instead	O
of	O
a	O
dedicated	O
ROM	B-Device
chip	I-Device
to	O
hold	O
graphics	O
data	O
(	O
called	O
CHR	O
by	O
Nintendo	O
)	O
,	O
games	O
using	O
UNROM	O
store	O
graphics	O
data	O
on	O
the	O
program	O
ROM	B-Device
and	O
copy	O
it	O
to	O
a	O
RAM	B-Architecture
on	O
the	O
cartridge	B-Protocol
at	O
run	O
time	O
.	O
</s>
<s>
Games	O
:	O
The	B-Application
Legend	I-Application
of	I-Application
Zelda	I-Application
,	O
Mega	B-Application
Man	I-Application
2	I-Application
,	O
Metroid	B-Device
,	O
Godzilla	B-Application
:	I-Application
Monster	I-Application
of	I-Application
Monsters	I-Application
,	O
Teenage	B-Application
Mutant	I-Application
Ninja	I-Application
Turtles	I-Application
,	O
and	O
more	O
.	O
</s>
<s>
Program	O
ROM	B-Device
can	O
be	O
selected	O
in	O
16KB	O
or	O
32KB	O
chunks	O
,	O
and	O
character	O
ROM	B-Device
can	O
be	O
selected	O
in	O
4KB	O
or	O
8KB	O
chunks	O
.	O
</s>
<s>
An	O
unusual	O
feature	O
of	O
this	O
memory	O
controller	O
is	O
that	O
its	O
input	O
is	O
serial	B-Protocol
,	O
rather	O
than	O
parallel	O
,	O
so	O
5	B-Application
sequential	O
writes	O
(	O
with	O
bit	O
shifting	O
)	O
are	O
needed	O
to	O
send	O
a	O
command	O
to	O
the	O
circuit	O
.	O
</s>
<s>
Games	O
:	O
Mike	B-Application
Tyson	I-Application
's	I-Application
Punch-Out	I-Application
!	I-Application
</s>
<s>
The	O
MMC2	O
is	O
only	O
used	O
in	O
Mike	B-Application
Tyson	I-Application
's	I-Application
Punch-Out	I-Application
!!	I-Application
</s>
<s>
A	O
single	O
8KB	O
bank	O
of	O
program	O
ROM	B-Device
can	O
be	O
selected	O
(	O
with	O
the	O
remaining	O
24KB	O
locked	O
)	O
and	O
character	O
ROM	B-Device
can	O
be	O
selected	O
in	O
two	O
pairs	O
of	O
4KB	O
banks	O
,	O
which	O
would	O
be	O
automatically	O
switched	O
when	O
the	O
video	O
hardware	O
attempts	O
to	O
load	O
particular	O
graphic	O
tiles	O
from	O
memory	O
,	O
thus	O
allowing	O
a	O
larger	O
amount	O
of	O
graphics	O
to	O
be	O
used	O
on	O
the	O
screen	O
without	O
the	O
need	O
for	O
the	O
game	O
itself	O
to	O
manually	O
switch	O
them	O
.	O
</s>
<s>
Games	O
:	O
Mega	B-Application
Man	I-Application
3	I-Application
,	O
4	B-Application
,	O
5	B-Application
,	O
6	B-Application
,	O
Super	O
Mario	O
Bros	O
.	O
2NA/EU	O
,	O
Super	B-Application
Mario	I-Application
Bros	I-Application
.	I-Application
3	I-Application
,	O
Kirby	B-Application
's	I-Application
Adventure	I-Application
,	O
and	O
more	O
.	O
</s>
<s>
It	O
adds	O
an	O
IRQ	B-General_Concept
timer	O
to	O
allow	O
split	O
screen	O
scrolling	O
without	O
the	O
sacrifice	O
of	O
sprite	O
0	O
,	O
along	O
with	O
two	O
selectable	O
8KB	O
program	O
ROM	B-Device
banks	O
and	O
two	O
2KB+four	O
1KB	O
selectable	O
character	O
ROM	B-Device
banks	O
,	O
which	O
allows	O
easy	O
instant	O
swapping	O
of	O
sprite	O
and	O
tile	O
data	O
.	O
</s>
<s>
8KB	O
of	O
save	O
game	O
RAM	B-Architecture
is	O
supported	O
.	O
</s>
<s>
Functionally	O
,	O
it	O
is	O
nearly	O
identical	O
to	O
the	O
MMC2	O
,	O
with	O
the	O
only	O
difference	O
being	O
that	O
the	O
MMC4	O
switches	O
program	O
ROM	B-Device
in	O
16KB	O
banks	O
instead	O
of	O
8KB	O
banks	O
and	O
has	O
support	O
for	O
a	O
battery-backed	O
SRAM	O
to	O
save	O
game	O
data	O
.	O
</s>
<s>
The	O
chip	O
has	O
1KB	O
of	O
extra	O
RAM	B-Architecture
,	O
two	O
extra	O
square	O
wave	O
sound	O
channels	O
,	O
one	O
extra	O
PCM	B-Algorithm
sound	O
channel	O
,	O
support	O
for	O
vertical	O
split	O
screen	O
scrolling	O
,	O
improved	O
graphics	O
capabilities	O
(	O
making	O
16,384	O
different	O
tiles	O
available	O
per	O
screen	O
rather	O
than	O
only	O
256	O
,	O
and	O
allowing	O
each	O
individual	O
8x8-pixel	O
background	O
tile	O
to	O
have	O
its	O
own	O
color	O
assignment	O
instead	O
of	O
being	O
restricted	O
to	O
one	O
color	O
set	O
per	O
2x2	O
tile	O
group	O
)	O
,	O
highly	O
configurable	O
program	O
ROM	B-Device
and	O
character	O
ROM	B-Device
bank	O
switching	O
,	O
and	O
a	O
scanline-based	O
IRQ	B-General_Concept
counter	O
.	O
</s>
<s>
The	O
MMC5	O
supports	O
up	O
to	O
2MB	O
total	O
ROM	B-Device
,	O
however	O
no	O
commercially	O
released	O
game	O
exceeded	O
1MB	O
.	O
</s>
<s>
The	O
MMC6	O
is	O
similar	O
to	O
the	O
MMC3	O
,	O
with	O
an	O
additional	O
1	O
KB	O
of	O
RAM	B-Architecture
which	O
can	O
be	O
saved	O
with	O
battery	O
backup	O
.	O
</s>
<s>
Games	O
:	O
Akumajo	B-Application
Dracula	I-Application
,	O
Arumana	B-Device
no	I-Device
Kiseki	I-Device
,	O
Ai	B-Application
Senshi	I-Application
Nicol	I-Application
,	O
Big	O
Challenge	O
!	O
</s>
<s>
Dogfight	O
Spirit	O
,	O
Bio	B-Application
Miracle	I-Application
Bokutte	I-Application
Upa	I-Application
,	O
CrackoutJP	O
,	O
Double	O
DribbleJP	O
,	O
Dracula	B-Application
II	I-Application
,	O
Falsion	B-Device
,	O
Famicom	B-Application
Tantei	I-Application
Club	I-Application
Part	I-Application
II	I-Application
:	I-Application
Ushiro	I-Application
ni	I-Application
Tatsu	I-Application
Shōjo	I-Application
,	O
Kid	O
IcarusJP	O
,	O
KiKi	B-Application
KaiKai	I-Application
,	O
Meikyuu	B-Device
Jiin	I-Device
Dababa	I-Device
,	O
MetroidJP	O
,	O
Pro	O
WrestlingJP	O
,	O
Relics	O
-	O
Ankoku	O
Yousai	O
,	O
Risa	B-Device
no	I-Device
Yōsei	I-Device
Densetsu	I-Device
,	O
Shin	B-Application
Onigashima	I-Application
,	O
Super	O
Mario	O
Bros	O
.	O
2JP	O
,	O
The	B-Application
Legend	I-Application
of	I-Application
Zelda	I-Application
(	O
FDS	O
release	O
)	O
,	O
The	B-Application
Mysterious	I-Application
Murasame	I-Application
Castle	I-Application
,	O
Vs.	O
Excitebike	O
,	O
Yūyūki	B-Application
,	O
Zelda	B-Application
II	I-Application
:	O
The	O
Adventure	O
of	O
LinkJP	O
,	O
and	O
more	O
.	O
</s>
<s>
The	O
Famicom	B-Device
Disk	I-Device
System	I-Device
's	O
ASIC	O
is	O
an	O
extended	O
audio	O
chip	O
,	O
which	O
supports	O
one	O
channel	O
of	O
single-cycle	O
(	O
6-bit	O
×	O
64	O
step	O
)	O
wavetable-lookup	O
synthesis	O
with	O
a	O
built	O
in	O
phase	B-Device
modulator	I-Device
(	O
PM	O
)	O
for	O
sound	O
generation	O
similar	O
to	O
frequency	O
modulation	O
synthesis	O
.	O
</s>
<s>
Some	O
cartridge	B-Protocol
conversions	O
of	O
Disk	B-Device
System	I-Device
games	O
have	O
MMCs	O
to	O
replace	O
the	O
audio	O
channel	O
.	O
</s>
<s>
Games	O
:	O
Battletoads	B-Application
,	O
Wizards	B-Application
&	I-Application
Warriors	I-Application
,	O
Cobra	B-Application
Triangle	I-Application
,	O
Jeopardy	O
!	O
</s>
<s>
The	O
A*ROM	O
MMC	O
,	O
named	O
after	O
the	O
AMROM	O
,	O
ANROM	O
,	O
and	O
AOROM	O
cartridge	B-Protocol
boards	O
that	O
use	O
it	O
,	O
was	O
developed	O
by	O
Chris	O
Stamper	O
of	O
Rare	O
,	O
and	O
manufactured	O
by	O
Nintendo	O
.	O
</s>
<s>
It	O
allows	O
the	O
PRG	O
ROM	B-Device
to	O
be	O
switched	O
in	O
a	O
single	O
32KB	O
piece	O
and	O
uses	O
CHR	O
RAM	B-Architecture
for	O
up	O
to	O
256KB	O
total	O
ROM	B-Device
.	O
</s>
<s>
Unlike	O
other	O
chips	B-Architecture
,	O
it	O
uses	O
one	O
screen	O
mirroring	O
.	O
</s>
<s>
Nintendo	O
maintained	O
tight	O
control	O
over	O
internationally-released	O
cartridge	B-Protocol
hardware	O
and	O
did	O
not	O
allow	O
third	O
parties	O
to	O
use	O
their	O
own	O
PCBs	O
and	O
mappers	O
.	O
</s>
<s>
As	O
a	O
result	O
most	O
third	O
party	O
mappers	O
will	O
only	O
be	O
found	O
in	O
Famicom	O
or	O
unlicensed	O
cartridges	B-Protocol
.	O
</s>
<s>
The	O
VRC2	O
is	O
a	O
chip	O
from	O
Konami	O
that	O
allows	O
program	O
ROM	B-Device
to	O
be	O
switched	O
in	O
8KB	O
banks	O
,	O
and	O
character	O
ROM	B-Device
to	O
be	O
switched	O
in	O
1KB	O
banks	O
.	O
</s>
<s>
Exclusively	O
used	O
in	O
the	O
Japanese	O
version	O
of	O
Salamander	B-Application
.	O
</s>
<s>
The	O
VRC4	O
Chip	O
is	O
similar	O
to	O
the	O
VRC2	O
chip	O
,	O
other	O
than	O
the	O
VRC4	O
allowing	O
for	O
512KB	O
CHR	O
capacity	O
,	O
2	O
8KB	O
PRG	O
ROM	B-Device
banking	O
modes	O
and	O
1	O
screen	O
mirroring	O
.	O
</s>
<s>
The	O
VRC6	O
(	O
Virtual	O
Rom	B-Device
Controller	O
)	O
is	O
an	O
advanced	O
MMC	O
chip	O
from	O
Konami	O
,	O
supporting	O
bank	O
switching	O
for	O
both	O
program	O
code	O
and	O
graphics	O
as	O
well	O
as	O
a	O
CPU	O
cycle	O
–	O
based	O
IRQ	B-General_Concept
counter	O
,	O
which	O
can	O
also	O
act	O
as	O
a	O
scanline	O
counter	O
.	O
</s>
<s>
It	O
is	O
used	O
in	O
Akumajō	B-Application
Densetsu	I-Application
(	O
the	O
Japanese	O
version	O
of	O
Castlevania	B-Application
III	I-Application
:	I-Application
Dracula	I-Application
's	I-Application
Curse	I-Application
)	O
,	O
while	O
the	O
Western	O
version	O
uses	O
the	O
MMC5	O
from	O
Nintendo	O
.	O
</s>
<s>
Since	O
the	O
Nintendo	O
Entertainment	O
System	O
does	O
not	O
allow	O
cartridges	B-Protocol
to	O
add	O
additional	O
sound	O
channels	O
,	O
the	O
Famicom	O
version	O
's	O
soundtrack	O
was	O
reworked	O
to	O
follow	O
those	O
specifications	O
;	O
thus	O
the	O
soundtrack	O
on	O
the	O
Western	O
version	O
is	O
implemented	O
by	O
the	O
five	O
sound	O
channels	O
built	O
into	O
the	O
stock	O
NES	O
.	O
</s>
<s>
The	O
VRC7	O
is	O
an	O
advanced	O
MMC	O
chip	O
from	O
Konami	O
,	O
supporting	O
bank	O
switching	O
and	O
IRQ	B-General_Concept
counting	O
equivalent	O
to	O
the	O
VRC6	O
,	O
and	O
containing	O
a	O
YM2413	O
derivative	O
providing	O
6	B-Application
channels	O
of	O
FM	O
Synthesis	O
audio	O
.	O
</s>
<s>
This	O
advanced	O
audio	O
is	O
used	O
only	O
in	O
the	O
Famicom	O
game	O
Lagrange	B-Application
Point	I-Application
.	O
</s>
<s>
The	O
Japanese	O
version	O
of	O
Tiny	B-Application
Toon	I-Application
Adventures	I-Application
2	O
uses	O
the	O
VRC7	O
but	O
not	O
the	O
extended	O
audio	O
.	O
</s>
<s>
A	O
variant	O
contained	O
extra	O
sound	O
hardware	O
that	O
plays	O
4-bit	O
wave	O
samples	O
.	O
</s>
<s>
It	O
supports	O
1	O
to	O
8	O
extra	O
sound	O
channels	O
,	O
but	O
audible	O
aliasing	B-Error_Name
appears	O
when	O
a	O
sufficiently	O
large	O
number	O
of	O
channels	O
are	O
enabled	O
.	O
</s>
<s>
Games	O
:	O
Batman	B-Application
:	I-Application
Return	I-Application
of	I-Application
the	I-Application
Joker	I-Application
,	O
Hebereke	O
,	O
and	O
more	O
.	O
</s>
<s>
The	O
FME-7	O
is	O
a	O
memory	O
mapping	O
circuit	O
developed	O
by	O
Sunsoft	O
for	O
use	O
in	O
NES	O
and	O
Famicom	O
cartridges	B-Protocol
.	O
</s>
<s>
It	O
switches	O
program	O
ROM	B-Device
in	O
8KB	O
banks	O
and	O
switches	O
the	O
character	O
ROM	B-Device
1KB	O
banks	O
.	O
</s>
<s>
It	O
also	O
contains	O
hardware	O
to	O
generate	O
IRQ	B-General_Concept
signals	O
after	O
a	O
specified	O
number	O
of	O
CPU	O
clock	O
cycles	O
,	O
thus	O
achieving	O
split-screen	O
effects	O
with	O
minimal	O
use	O
of	O
processing	O
power	O
.	O
</s>
<s>
Games	O
:	O
Gimmick	B-Application
!	I-Application
</s>
<s>
This	O
version	O
of	O
the	O
FME-7	O
contains	O
a	O
version	O
of	O
the	O
widely	O
used	O
Yamaha	B-Device
YM2149	I-Device
.	O
</s>
<s>
228	O
is	O
a	O
simple	O
bank	O
switching	O
MMC	O
developed	O
for	O
use	O
in	O
the	O
games	O
Action	B-Application
52	I-Application
and	O
Cheetahmen	B-Device
II	I-Device
.	O
</s>
<s>
In	O
the	O
Action	B-Application
52	I-Application
multicart	O
,	O
it	O
also	O
contains	O
a	O
small	O
16-bit	O
register	O
area	O
that	O
contains	O
the	O
old	O
menu	O
selection	O
when	O
exiting	O
a	O
game	O
.	O
</s>
<s>
The	O
board	O
contains	O
512K	O
of	O
PRG	O
ROM	B-Device
,	O
16K	O
of	O
CHR	O
ROM	B-Device
,	O
and	O
two	O
LEDs	O
.	O
</s>
<s>
While	O
the	O
GTROM	O
does	O
not	O
contain	O
PRG	O
RAM	B-Architecture
,	O
saved	O
games	O
are	O
possible	O
due	O
to	O
PRG	O
ROM	B-Device
being	O
flashable	O
by	O
NES	O
software	O
.	O
</s>
