Atari 800

PITCH VALUES FOR THE MUSICAL NOTES-AUDCTL =0, AUDC = hex AX
AUDF
Hex
Dec
HIGH
c lD
29
NOTES
B lF
31
All or Bb
21
33
A
23
35
Gil or Ab
25
37
G
28
40
Fll or Gb
2A
42
F 2D 45
E
2F
47
D/1 or Eb 32 50
D
35
53
ell or
Db
39
57
c
3C
60
B 40
64
All
or
Bb 44 68
A
48
72
Gil or Ab 4C
76
G 51
81
Fll or Gb 55
85
F 5B
91
E 60
96
Dll or
Eb
66
102
D
6C
~ 108
ell or
Db
72 114
MIDDLE C
c 79 121
B
80 128
All
or Bb 88 136
A
90
144
Gil or Ab 99
153
G
A2 162
Fll or Gb AD
173
F
B6
182
E
Cl 193
Dll or
Eb cc 204
D
D9 217
LOW
ell or
Db E6 230
NOTES
c
F3 243
STIMER ~Start Timer)~D209):
This write address resets all audio
frequency dividers to their "AUDF" value. These dividers generate timer
interrupts when they count down to zero (if enabled by IRQEN).
(also see
IRQST)
not used
RANDOM (Random Number Generator)(D20A): This address reads the high
order 8 bits of a 17 bit polynomial counter (9 bit, if bit 7 of AUDCTL=l).
D7 D6 D5 D4 D3 D2
Dl I DO I
III.l4