AMSTRAD CPC464 User Manual page 52

Now replace all the lines by typing in:
5 e n v 1 , 1 0 0 , 2 , 2
1 0 e n t 1 , 1 00, -2,2
2 0 s o u n d 1 , 2 8 4 , 2 0 0 , 1 , 1 , 1
run
Try some more variations for yourself.
NOISE
Noise can be added to the end of the sound command. A range of noise is available in the range 1 to
31. Try this by adding the noise number at the end of the sound command still using the envelope
command.
Replace lines 5 and 20 by typing in:
5 e n v 1 , 1 0 0 , 3 , 1
2 0 s o u n d 1 , 2 0 0 , 1 0 0 , 1 , 1 , 1 , 5
run
Again, try to get some unusual sounds by modifying the volume envelope and the sound command,
with and without noise.