<s>
The	O
Ricoh	B-General_Concept
2A03	I-General_Concept
or	O
RP2A03	B-General_Concept
(	O
NTSC	O
version	O
)	O
/	O
Ricoh	B-General_Concept
2A07	I-General_Concept
or	O
RP2A07	B-General_Concept
(	O
PAL	B-Language
version	O
)	O
is	O
an	O
8-bit	O
microprocessor	B-Architecture
manufactured	O
by	O
Ricoh	O
for	O
the	O
Nintendo	O
Entertainment	O
System	O
video	B-Device
game	I-Device
console	I-Device
.	O
</s>
<s>
It	O
was	O
also	O
used	O
as	O
a	O
sound	O
chip	O
and	O
secondary	O
CPU	O
by	O
Nintendo	O
's	O
arcade	O
games	O
Punch-Out	B-Application
!!	I-Application
</s>
<s>
and	O
Donkey	B-Application
Kong	I-Application
3	I-Application
.	O
</s>
<s>
The	O
Ricoh	B-General_Concept
2A03	I-General_Concept
contains	O
a	O
second-sourced	O
MOS	B-General_Concept
Technology	I-General_Concept
6502	I-General_Concept
core	O
,	O
modified	O
to	O
disable	O
the	O
6502	B-General_Concept
's	O
binary-coded	O
decimal	O
mode	O
(	O
possibly	O
to	O
avoid	O
a	O
MOS	O
Technology	O
patent	O
)	O
.	O
</s>
<s>
It	O
also	O
integrates	O
a	O
programmable	O
sound	O
generator	O
(	O
also	O
known	O
as	O
APU	O
,	O
featuring	O
twenty	O
two	O
memory-mapped	B-Architecture
I/O	I-Architecture
registers	O
)	O
,	O
rudimentary	O
DMA	B-General_Concept
,	O
and	O
game	O
controller	O
polling	O
.	O
</s>
<s>
The	O
Ricoh	B-General_Concept
2A03	I-General_Concept
's	O
sound	O
hardware	O
has	O
5	O
channels	O
,	O
separated	O
into	O
two	O
APUs	O
(	O
Audio	O
Processing	O
Units	O
)	O
.	O
</s>
<s>
The	O
first	O
APU	O
contains	O
two	O
general	O
purpose	O
pulse	O
channels	O
with	O
4	O
duty	O
cycles	O
,	O
and	O
the	O
second	O
APU	O
contains	O
a	O
Triangle	O
wave	O
generator	O
,	O
an	O
LFSR-based	O
Noise	O
generator	O
,	O
and	O
a	O
1-bit	O
Delta	O
modulation-encoded	O
PCM	O
(	O
DPCM	O
)	O
channel	O
.	O
</s>
<s>
For	O
example	O
,	O
Super	B-Application
Mario	I-Application
Bros	I-Application
.	I-Application
3	I-Application
uses	O
the	O
DPCM	O
channel	O
for	O
simple	O
drum	O
sounds	O
,	O
while	O
Journey	B-Application
to	I-Application
Silius	I-Application
uses	O
it	O
for	O
sampled	O
basslines	O
.	O
</s>
<s>
PAL	B-Language
versions	O
of	O
the	O
NES	O
(	O
sold	O
in	O
Europe	O
,	O
Asia	O
,	O
and	O
Australia	O
)	O
use	O
the	O
Ricoh	B-General_Concept
2A07	I-General_Concept
or	O
RP2A07	B-General_Concept
processor	O
,	O
which	O
is	O
a	O
2A03	B-General_Concept
with	O
modifications	O
to	O
better	O
suit	O
the	O
50Hz	O
vertical	O
refresh	O
rate	O
used	O
in	O
the	O
PAL	B-Language
television	O
standard	O
.	O
</s>
<s>
However	O
,	O
most	O
developers	O
lacked	O
the	O
resources	O
to	O
properly	O
adjust	O
their	O
games	O
 '	O
music	O
from	O
NTSC	O
to	O
PAL	B-Language
,	O
leading	O
to	O
many	O
PAL	B-Language
games	O
sounding	O
slower	O
,	O
slightly	O
lower-pitched	O
,	O
and	O
in	O
some	O
cases	O
,	O
out-of-tune	O
compared	O
to	O
their	O
original	O
NTSC	O
releases	O
.	O
</s>
