<s>
The	O
AY-3-8910	B-Device
is	O
a	O
3-voice	O
programmable	O
sound	O
generator	O
(	O
PSG	O
)	O
designed	O
by	O
General	O
Instrument	O
in	O
1978	O
,	O
initially	O
for	O
use	O
with	O
their	O
16-bit	O
CP1610	O
or	O
one	O
of	O
the	O
PIC1650	O
series	O
of	O
8-bit	O
microcomputers	O
.	O
</s>
<s>
The	O
AY-3-8910	B-Device
and	O
its	O
variants	O
were	O
used	O
in	O
many	O
arcade	O
gamesKonami	O
's	O
Gyruss	B-Application
contains	O
fiveand	O
pinball	B-Application
machines	O
as	O
well	O
as	O
being	O
the	O
sound	O
chip	O
in	O
the	O
Intellivision	B-Operating_System
and	O
Vectrex	B-Operating_System
video	O
game	O
consoles	O
,	O
and	O
the	O
Amstrad	B-Device
CPC	I-Device
,	O
Oric-1	O
,	O
Colour	B-Device
Genie	I-Device
,	O
Elektor	B-Device
TV	I-Device
Games	I-Device
Computer	I-Device
,	O
MSX	B-Operating_System
,	O
and	O
later	O
ZX	B-Operating_System
Spectrum	I-Operating_System
home	O
computers	O
.	O
</s>
<s>
It	O
was	O
also	O
used	O
in	O
the	O
Mockingboard	O
and	O
Cricket	O
sound	O
cards	O
for	O
the	O
Apple	B-Device
II	I-Device
and	O
the	O
Speech/Sound	O
Cartridge	O
for	O
the	O
TRS-80	B-Device
Color	I-Device
Computer	I-Device
.	O
</s>
<s>
It	O
was	O
also	O
manufactured	O
under	O
license	O
by	O
Yamaha	O
(	O
with	O
a	O
selectable	O
clock	O
divider	O
pin	O
and	O
a	O
double-resolution	O
and	O
double-rate	O
volume	O
envelope	O
table	O
)	O
as	O
the	O
YM2149F	B-Device
;	O
the	O
Atari	B-Device
ST	I-Device
uses	O
this	O
version	O
.	O
</s>
<s>
It	O
produces	O
very	O
similar	O
results	O
to	O
the	O
Texas	B-Device
Instruments	I-Device
SN76489	I-Device
and	O
was	O
on	O
the	O
market	O
for	O
a	O
similar	O
period	O
.	O
</s>
<s>
An	O
unofficial	O
VHDL	B-Language
description	O
is	O
freely	O
available	O
for	O
use	O
with	O
FPGAs	B-Architecture
.	O
</s>
<s>
The	O
AY-3-8910	B-Device
was	O
essentially	O
a	O
state	B-Architecture
machine	I-Architecture
,	O
with	O
the	O
state	O
being	O
set	O
up	O
in	O
a	O
series	O
of	O
sixteen	O
8-bit	O
registers	B-General_Concept
.	O
</s>
<s>
This	O
bus	O
was	O
implemented	O
natively	O
on	O
GI	O
's	O
own	O
CPUs	O
,	O
but	O
it	O
had	O
to	O
be	O
recreated	O
in	O
glue	O
logic	O
or	O
with	O
the	O
help	O
of	O
an	O
additional	O
interface	O
adapter	O
such	O
as	O
the	O
MOS	B-Device
Technology	I-Device
6522	I-Device
when	O
the	O
chip	O
was	O
used	O
with	O
the	O
much	O
more	O
common	O
MOS	B-General_Concept
Technology	I-General_Concept
6502	I-General_Concept
or	O
Zilog	B-General_Concept
Z80	I-General_Concept
CPUs	O
.	O
</s>
<s>
Six	O
registers	B-General_Concept
controlled	O
the	O
pitches	O
produced	O
in	O
the	O
three	O
primary	O
channels	O
.	O
</s>
<s>
The	O
wavelength	O
to	O
generate	O
was	O
held	O
in	O
two	O
eight-bit	O
registers	B-General_Concept
dedicated	O
to	O
each	O
channel	O
,	O
but	O
the	O
value	O
was	O
limited	O
to	O
12-bits	O
for	O
other	O
reasons	O
,	O
for	O
a	O
total	O
of	O
4095	O
(	O
the	O
register	O
value	O
is	O
used	O
as	O
the	O
frequency	O
divider	O
and	O
0	O
is	O
treated	O
as	O
1	O
)	O
different	O
pitches	O
.	O
</s>
<s>
Three	O
additional	O
registers	B-General_Concept
controlled	O
the	O
volume	O
of	O
the	O
channels	O
,	O
as	O
well	O
as	O
turning	O
on	O
or	O
off	O
the	O
optional	O
envelope	O
controls	O
on	O
them	O
.	O
</s>
<s>
Finally	O
the	O
last	O
three	O
registers	B-General_Concept
controlled	O
the	O
times	O
of	O
the	O
envelope	O
controller	O
,	O
by	O
setting	O
the	O
envelope	O
type	O
and	O
envelope	O
cycle	O
time	O
.	O
</s>
<s>
Although	O
there	O
are	O
only	O
16	O
registers	B-General_Concept
,	O
the	O
four	O
MSB	O
bits	O
of	O
the	O
8-bit	O
bus	O
must	O
be	O
set	O
to	O
the	O
factory	O
default	O
'	O
0000	O
 '	O
value	O
when	O
selecting	O
a	O
register	O
.	O
</s>
<s>
The	O
chips	O
made	O
with	O
customize-set	O
MSB	O
register	O
bits	O
allow	O
the	O
same	O
processor	O
to	O
control	O
more	O
than	O
one	O
AY	B-Device
chip	I-Device
on	O
the	O
same	O
bus	O
(	O
e.g.	O
</s>
<s>
TurboSound	O
for	O
ZX	B-Operating_System
Spectrum	I-Operating_System
)	O
.	O
</s>
<s>
The	O
AY-3-8910	B-Device
generates	O
tones	O
with	O
base	O
frequencies	O
of	O
up	O
to	O
125	O
kHz	O
(	O
4	O
MHz	O
input	O
clock	O
,	O
or	O
6	O
MHz	O
with	O
the	O
YM2149F	B-Device
)	O
,	O
well	O
beyond	O
human	O
perception	O
and	O
into	O
the	O
ultrasonic	O
range	O
.	O
</s>
<s>
By	O
contrast	O
,	O
the	O
SN76489	B-Device
only	O
has	O
10	O
bits	O
of	O
precision	O
for	O
its	O
frequency	O
dividers	O
.	O
</s>
<s>
To	O
get	O
around	O
this	O
,	O
the	O
SN76489	B-Device
plays	O
its	O
tone	O
generators	O
one	O
octave	O
lower	O
than	O
their	O
calculated	O
frequency	O
,	O
giving	O
it	O
one	O
octave	O
less	O
in	O
the	O
bass	O
and	O
one	O
octave	O
less	O
in	O
the	O
top	O
compared	O
to	O
the	O
PSG	O
.	O
</s>
<s>
The	O
AY-3-8910	B-Device
has	O
two	O
general-purpose	O
8-bit	O
parallel	O
I/O	B-General_Concept
ports	O
,	O
A	O
and	O
B	O
,	O
and	O
these	O
are	O
available	O
in	O
the	O
40-pin	O
package	O
of	O
the	O
same	O
name	O
.	O
</s>
<s>
The	O
AY-3-8912	B-Device
is	O
the	O
same	O
chip	O
in	O
a	O
28-pin	O
package	O
,	O
with	O
parallel	O
port	O
B	O
simply	O
not	O
connected	O
to	O
any	O
pins	O
.	O
</s>
<s>
The	O
AY-3-8913	B-Device
is	O
the	O
same	O
chip	O
in	O
a	O
24-pin	O
package	O
,	O
with	O
both	O
parallel	O
ports	O
not	O
connected	O
.	O
</s>
<s>
Some	O
users	O
thought	O
the	O
small	O
reduction	O
in	O
pin	O
count	O
over	O
the	O
8912	O
made	O
it	O
less	O
interesting	O
;	O
however	O
,	O
the	O
I/O	B-General_Concept
registers	B-General_Concept
were	O
rarely	O
used	O
by	O
designers	O
so	O
General	O
Instruments	O
created	O
this	O
fully	O
functional	O
24	O
pin	O
alternative	O
and	O
released	O
it	O
approximately	O
6	O
months	O
after	O
the	O
8910	O
and	O
8912	O
chips	O
.	O
</s>
<s>
The	O
Yamaha	O
YM2149F	B-Device
SSG	O
(	O
Software-controlled	O
Sound	O
Generator	O
)	O
chip	O
has	O
the	O
same	O
pinout	O
as	O
the	O
AY-3-8910	B-Device
,	O
with	O
the	O
minor	O
difference	O
that	O
pin	O
26	O
could	O
halve	O
the	O
master	O
clock	O
if	O
pulled	O
low	O
.	O
</s>
<s>
If	O
left	O
unconnected	O
,	O
as	O
it	O
would	O
be	O
if	O
replacing	O
an	O
AY-3-8910	B-Device
chip	O
,	O
an	O
internal	O
resistor	O
pulls	O
the	O
pin	O
high	O
,	O
so	O
the	O
master	O
clock	O
is	O
not	O
halved	O
.	O
</s>
<s>
The	O
Yamaha	O
YM3439	O
is	O
a	O
CMOS	O
version	O
of	O
the	O
YM2149F	B-Device
.	O
</s>
<s>
The	O
Yamaha	O
YMZ294	O
is	O
one	O
of	O
the	O
newest	O
variants	O
of	O
the	O
YM2149	B-Device
,	O
but	O
in	O
an	O
18-pin	O
package	O
.	O
</s>
<s>
The	O
Yamaha	O
YMZ284	O
is	O
an	O
even	O
smaller	O
variation	O
of	O
the	O
YM2149	B-Device
,	O
in	O
a	O
16-pin	O
package	O
.	O
</s>
<s>
The	O
Toshiba	O
T7766A	O
is	O
a	O
compatible	O
chip	O
that	O
has	O
the	O
same	O
pinout	O
as	O
the	O
AY-3-8910	B-Device
and	O
was	O
used	O
in	O
some	O
MSX	B-Operating_System
models	O
.	O
</s>
<s>
The	O
Winbond	O
WF19054	O
,	O
JFC	O
95101	O
and	O
the	O
File	O
KC89C72	O
have	O
the	O
same	O
pinout	O
as	O
the	O
AY-3-8910	B-Device
and	O
are	O
also	O
100%	O
software	O
compatible	O
.	O
</s>
<s>
The	O
AY-3-8914	O
has	O
the	O
same	O
pinout	O
and	O
is	O
in	O
the	O
same	O
40-pin	O
package	O
as	O
the	O
AY-3-8910	B-Device
,	O
except	O
the	O
control	O
registers	B-General_Concept
on	O
the	O
chip	O
are	O
shuffled	O
around	O
,	O
and	O
the	O
'	O
expected	O
input	O
 '	O
on	O
the	O
A9	O
pin	O
may	O
be	O
different	O
.	O
</s>
<s>
It	O
was	O
used	O
in	O
Mattel	O
's	O
Intellivision	B-Operating_System
console	O
and	O
Aquarius	B-Device
computer	O
.	O
</s>
<s>
The	O
AY-3-8930	O
,	O
also	O
known	O
as	O
AY8930	O
,	O
is	O
an	O
enhanced	O
but	O
mostly-backwards-compatible	O
version	O
of	O
the	O
AY-3-8910	B-Device
.	O
</s>
<s>
The	O
function	O
of	O
the	O
BC2	O
pin	O
is	O
changed	O
(	O
it	O
is	O
ignored	O
and	O
assumed	O
to	O
be	O
0	O
regardless	O
of	O
the	O
pin	O
state	O
)	O
,	O
otherwise	O
the	O
pinout	O
is	O
the	O
same	O
as	O
the	O
AY-3-8910	B-Device
.	O
</s>
<s>
Very	O
few	O
games	O
took	O
advantage	O
of	O
it	O
beyond	O
the	O
normal	O
AY-3-8910	B-Device
features	O
.	O
</s>
<s>
Yamaha	O
used	O
the	O
YM2149	B-Device
core	O
to	O
produce	O
a	O
whole	O
family	O
of	O
music	O
chips	O
which	O
were	O
used	O
in	O
mobile	O
phones	O
,	O
home	O
computers	O
,	O
home	O
and	O
arcade	O
video	O
game	O
systems	O
,	O
etc	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
YM2203	O
(	O
also	O
known	O
as	O
OPN	O
)	O
is	O
basically	O
a	O
YM2149	B-Device
with	O
FM	O
synthesis	O
added	O
in	O
,	O
as	O
well	O
as	O
its	O
far	O
more	O
advanced	O
successors	O
:	O
the	O
YM2608	O
(	O
also	O
known	O
as	O
OPNA	O
)	O
which	O
retained	O
all	O
previous	O
features	O
and	O
greatly	O
expanded	O
upon	O
those	O
,	O
the	O
YM2610	O
(	O
OPNB	O
)	O
which	O
added	O
other	O
features	O
and	O
retained	O
the	O
YM2149	B-Device
sound	O
channels	O
but	O
not	O
the	O
I/O	B-General_Concept
ports	O
,	O
and	O
the	O
YM2612	O
(	O
also	O
known	O
as	O
OPN2	O
)	O
which	O
added	O
some	O
features	O
but	O
removed	O
all	O
other	O
ones	O
including	O
the	O
YM2149	B-Device
sound	O
channels	O
and	O
I/O	B-General_Concept
ports	O
.	O
</s>
<s>
NEC	B-Device
PC-8801	I-Device
(	O
Yamaha	O
OPN	O
,	O
models	O
PC8801mkII	O
SR	O
models	O
and	O
newer	O
.	O
</s>
<s>
/	O
Yamaha	O
OPNA	O
,	O
models	O
PC8801	B-Device
FA	O
and	O
newer	O
.	O
)	O
</s>
<s>
NEC	B-Operating_System
PC-9801	I-Operating_System
(	O
Yamaha	O
OPN	O
/	O
OPNA	O
(	O
some	O
models	O
)	O
,	O
Sound	O
Cards	O
:	O
PC-9801-26	O
,	O
PC-9801-86	O
,	O
Sound	O
Blaster	O
16	O
(	O
Optional	O
socket	O
)	O
and	O
others	O
.	O
)	O
</s>
