Sound_Control (changes)
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Programmer's SoundChannels Reference Manuals
» Part 15 – SWI Calls
» Sound_ControlSound
» Sound_Control
Sound_Control
(SWI &40189)
| Entry | |
|---|---|
| R0 | Channel number (1-8) |
| R1 | Amplitude: |
| &FFF1 – &FFFF and 0 for BBC emulation amplitude (0 to -15) | |
| &0001 – &000F BBC envelope not emulated | |
| &0100 – &01FF for full amplitude/gate control: | |
| bit 7 is: | |
| 0 for gate ON/OFF | |
| 1 for smooth update (gate not retriggered) | |
| bits 6 – 0 are 7-bit logarithm of amplitude | |
| R2 | Pitch: |
| &0000 – &00FF for BBC emulation pitch | |
| &0100 – &7FFF for enhanced pitch control: | |
| bits 14 – 12 = 3-bit octave | |
| bits 11 – 0 = 12-bit fractional part of octave (&4000 is Middle C) | |
| &8000 + n for phase accumulator increment (n is 0 – &7FFF) | |
| R3 | Duration: |
| &0001 – &00FE for BBC emulation in 5 centisecond periods | |
| &00FF for BBC emulation ‘infinite’ time (converted to &F0000000) | |
| > &00FF for duration in 5 centisecond periods |
| Exit | |
|---|---|
| R0-R3 | Preserved |
Use
Plays a sound immediately on the given channel.
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