Atari XL

Sound and Music 103
F
R
E
Q
u
E
N
C
y
SQUARE WAVE
-
FILTERING WAVE
-----.In n r
RESULTANT WAVE
TIME •
60 POKE 53765,168
If you delete line 20, the two tone channels alone
will be heard.
Finally, bit 7 of the peR controls the rate at which
the pattern of the square wave controlling the
distortion repeats, and when set to 1, makes any
distorted sound much more regular, as the
following example shows. You will hear the sound
change after about two seconds, as line 50 sets bit 7
in the peR.
10 SOUND 0,10,8,8
20 SOUND 1,100,8,8
30 SOUND 2,255,8,8
40 FOR D=O TO 1000:NEXT D