<s>
The	O
SN76489	B-Device
Digital	O
Complex	O
Sound	O
Generator	O
(	O
DCSG	O
)	O
is	O
a	O
TTL-compatible	O
programmable	O
sound	O
generator	O
chip	O
from	O
Texas	O
Instruments	O
.	O
</s>
<s>
Its	O
main	O
application	O
was	O
the	O
generation	O
of	O
music	O
and	O
sound	O
effects	O
in	O
game	O
consoles	O
,	O
arcade	O
games	O
and	O
home	O
computers	O
(	O
such	O
as	O
the	O
TI-99/4A	B-Device
,	O
BBC	B-Device
Micro	I-Device
,	O
ColecoVision	B-Device
,	O
IBM	B-Device
PCjr	I-Device
,	O
Tomy	O
Tutor	O
,	O
and	O
Tandy	O
1000	O
)	O
,	O
competing	O
with	O
the	O
similar	O
General	B-Device
Instrument	I-Device
AY-3-8910	I-Device
.	O
</s>
<s>
The	O
SN76489	B-Device
was	O
originally	O
designed	O
to	O
be	O
used	O
in	O
the	O
TI-99/4	B-Device
computer	O
,	O
where	O
it	O
was	O
first	O
called	O
the	O
TMS9919	B-Device
and	O
later	O
SN94624	B-Device
,	O
and	O
had	O
a	O
500kHz	O
max	O
clock	O
input	O
rate	O
.	O
</s>
<s>
Later	O
,	O
when	O
it	O
was	O
sold	O
outside	O
of	O
TI	O
,	O
it	O
was	O
renamed	O
the	O
SN76489	B-Device
,	O
and	O
a	O
divide-by-8	O
was	O
added	O
to	O
its	O
clock	O
input	O
,	O
increasing	O
the	O
max	O
clock	O
input	O
rate	O
to	O
,	O
to	O
facilitate	O
sharing	O
a	O
crystal	O
for	O
both	O
NTSC	O
colorburst	O
and	O
clocking	O
the	O
sound	O
chip	O
.	O
</s>
<s>
A	O
version	O
of	O
the	O
chip	O
without	O
the	O
divide-by-8	O
input	O
was	O
also	O
sold	O
outside	O
of	O
TI	O
as	O
the	O
SN76494	B-Device
,	O
which	O
has	O
a	O
max	O
clock	O
input	O
rate	O
.	O
</s>
<s>
There	O
are	O
two	O
versions	O
of	O
the	O
SN76489	B-Device
:	O
the	O
SN76489	B-Device
(	O
Narrow	B-Algorithm
DIP	I-Algorithm
version	O
labeled	O
SN76489N	O
)	O
and	O
the	O
SN76489A	B-Device
(	O
Narrow	B-Algorithm
DIP	I-Algorithm
version	O
labeled	O
SN76489AN	O
)	O
.	O
</s>
<s>
They	O
differ	O
in	O
that	O
the	O
output	O
of	O
the	O
SN76489	B-Device
is	O
the	O
inverse	O
of	O
the	O
expected	O
waveform	O
(	O
the	O
waveform	O
"	O
grows	O
"	O
towards	O
0V	O
from	O
2.5V	O
)	O
,	O
while	O
the	O
SN76489A	B-Device
the	O
waveform	O
is	O
not	O
inverted	O
.	O
</s>
<s>
The	O
SN76496	B-Device
seems	O
to	O
be	O
totally	O
identical	O
to	O
the	O
SN76489A	B-Device
in	O
terms	O
of	O
the	O
outputs	O
produced	O
,	O
but	O
features	O
an	O
"	O
AUDIO	O
IN	O
"	O
pin	O
(	O
on	O
pin	O
9	O
)	O
for	O
integrated	O
audio	O
mixing	O
.	O
</s>
<s>
Sega	O
used	O
real	O
SN76489AN	O
chips	O
in	O
their	O
SG-1000	B-Operating_System
game	O
console	O
and	O
SC-3000	O
computer	O
,	O
but	O
used	O
SN76489A	B-Device
clones	O
in	O
their	O
Master	O
System	O
,	O
Game	O
Gear	O
,	O
and	O
Sega	B-Operating_System
Genesis	I-Operating_System
game	O
consoles	O
.	O
</s>
<s>
Although	O
basic	O
functionality	O
is	O
almost	O
identical	O
to	O
that	O
of	O
the	O
original	O
SN76489A	B-Device
,	O
a	O
few	O
small	O
differences	O
exist	O
:	O
</s>
<s>
Later	O
Tandy	O
1000	O
machines	O
(	O
notably	O
the	O
SL	O
,	O
TL	O
and	O
RL	O
series	O
)	O
integrated	O
the	O
SN76496	B-Device
's	O
functionality	O
into	O
the	O
PSSJ	O
ASIC	O
.	O
</s>
<s>
These	O
games	O
shared	O
a	O
common	O
board	O
design	O
by	O
Tehkan	O
that	O
used	O
three	O
of	O
the	O
functionally	O
identical	O
SN76496	B-Device
:	O
</s>
<s>
Mr.	B-Application
Do	I-Application
!	I-Application
</s>
