Commodore 128 Programmer's Reference Manual page 620

610 COMMODORE 128
ATTACK:
DECAY:
SUSTAIN:
RELEASE:
0 2 ms
0 6 ms
15($F)
0 6 ms
r i
GATE
L
The real power of SID lies in the ability to create original sounds rather than
simulations of acoustic instruments. The ADSR is capable of creating envelopes which
do not correspond to any "real" instruments. A good example would be the "back
wards" envelope. This envelope is characterized by a slow attack and rapid decay
which sounds very much like an instrument that has been recorded on tape then played
backwards. This envelope is shown below:
ATTACK:
DECAY:
SUSTAIN:
RELEASE:
10 ($A)
0
15 ($F)
3
500 ms
6 ms
72 ms
d L_
Many unique sounds can be created by applying the amplitude envelope of one
instrument to the harmonic structure of another. This produces sounds similar to familiar
acoustic instruments, yet notably different. In general, sound is quite subjective and
experimentation with various envelope rates and harmonic contents will be necessary in
order to achieve the desired sound.
RES
2 OUT
R/W
650X
MPU
2200 pF
POLYSTYRENE
ADDRESS DECODING
OR ADDRESS LINE
L_L
CAP1A
CAP2B
RES'
".D
A0
GND
AUDIO
ELECTROLYTIC 0UT
ELECTROLYTIC
~. 1000 pF
d± 1000 pF
Figure 16-18. Typical 6581/SID Application
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