AMSTRAD CPC464 User Manual page 123

Form of the command:
E N V N , P l , Q l , R l , P 2 , Q 2 , R 2 , P 3 , Q 3 , R 3 , P 4 , Q 4 , R 4 , P 5 , Q 5 , R 5
N: Envelope Number value range 1....15
Pl.... 5 : Step Count (sections l.... 5)
Ql.... 5 : Step Size (sections l.... 5)
Rl.. . .5 : Pause Time (sections l.... 5)
The <envelope number> is a compulsory label. A complete section is mandatory, but the number of
sections is optional. For example, omitting sections 4 and 5 assumes only 3 sections.
6.12 The command and tone envelopes
ENT
These have exactly the same type of construction as volume envelopes, only this feature creates
small variations in frequency of a note, in other words, a form of vibrato. After deciding on the
shapes of the note' s frequency, sketch it as before and divide into sections and steps. see example
below :
Figure 4: Characteristics of a tone envelope
The major difference between volume envelopes and tone envelopes is that tone envelopes have no
effect on the duration of a note previously defined - either in the SOUND command or in a volume
envelope. If the tone envelope finishes before the note then the final tone period continues. However,
if it overruns the time scale of the note then the remaining steps' sections are abandoned.
To repeat a tone envelope for the duration of the sound, use a negative envelope number. (Note It is
not called up as negative in the SOUND command).
Form of the command:
E N T S , T l , V l , W l ,T 2 , V 2 , W 2 , T 3 , V 3 , W 3 , T 4 , V 4 , W 4 , T 5 , V 5 , W 5
S: Envelope Number value range 1....15 (-ve for repeat)
Tl.... 5 : Step Count (sec. l.... 5)
Vl..., 5 : Step Size (sec. 1....5)
value range 0 . . . . 127
value range -128....+127
value range 0 . . . . 255
value range 0....239
value range -128....+127