Atari 800

AUDF1, AUDF2, AUDF3, AUDF4 (Audio Frequency) (D200, D202, D204, D206)
These addresses write data into each of the four Audio Frequency Control
Registers. Each register controls a divide by "N" counter.
I
I
I I
I
D7
I D6 I
D5
I
D4
I D3 I
0 0 0 0 0
0 0 0 0 0
ETC.
1 1 1 1 1
I
D2
J
D1
0 0
0 0
1 1
I
l
DO
0
1
1
"N"
1
2
256
Note: "N" is one greater
than the binary number
in Audio Frequency
Register AUDF(X).
AUDC1, AUDC2, AUDC3, AUDC4 (Audio Channel Control)(D201, D203,
D205, D207):
These addresses write data into each of the four Audio Control
Registers. Each Register controls the noise content and volume of the
corresponding Audio Channel.
Noise Content or Distortion Volume
I I I I I I
Divisor "N" set
HEX D7
I D6 I D5 I D4
D3 I
D2
I D1 I
DO by audio frequency
register.
0 0 0 0 0
- 17 BIT
poly- 5 BIT
poly - N
2
0 0 1
0
- 5 BIT
poly
- N - 2
4
0 1 0
0
- 4
BIT
poly -
5
BIT
poly - N
6 0 1 1
0
- 5 BIT
poly - N -
2
8 1 0 0 0 - 17 BIT poly
- N
A
1 X
1 0
-
Pure Tone -
N -
2
c
1 1
0
0
- 4 BIT
poly - N
1
X
X X 1 -
Force Output
(Volume only)
0 0
0 0 0 -
Lowest Volume
(Off)
8 1
0
0 0
- Half Volume
F
1
1 1 1 -
Highest Volume
III .13