Commodore 128D - Page 145

+1 in line 30 tells the computer to generate a random number in the
range between 1 and 3. The procedure for generating a random
number in a specific range is to multiply the given random number
times the maximum value of the parameter (in this case, 3). If the
minimum value of the parameter is greater than zero, add to the ran
dom number a value that will specify the minimum value of the range
of numbers you want to generate (in this case, 1). For instance, line
40 generates a random number in the range between 0 and 65535.
Since the minimum value is zero in this case, you do not need to add
a value to the generated random number.
Line 110 PRINTs the values of the parameters. Line 120 plays the
SOUND specified by the random numbers generated in lines 30
through 100. Line 130 delays the program for 4 seconds while the
sound is playing. Line 140 turns off the SOUND after the 4 second
delay. All sounds generated by this program play for the same
amount of time, since they are all turned off after 4 seconds with line
140. Finally, line 150 returns control to line 10, and the process is
repeated until you press the RUN/STOP and RESTORE keys at the
same time.
So far you have experimented with sample programs using only the
SOUND statement. Although you can use the SOUND statement to
play musical scores, it is best suited for quick and easy sound
effects like the ones in the dogfight program. The CommodSre 128
has other statements designed specifically for song playing. The
following paragraphs describe the advanced sound and music state
ments that enable you to play complex musical scores and arrange
ments with your Commodore 128 synthesizer.
137 USING C128 MODE—Sound and Music in C.128 Mode