h6. [[SoundChannels]] h6(. » [[SoundChannels SWI Calls|SWI Calls]] h6((. » Sound_Control h2. Sound_Control h5. (SWI &40189) |_<^{width:4em}. 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 | |_<^{width:4em}. Exit | | |<^. R0-R3 |<^. Preserved | h4. Use Plays a sound immediately on the given channel.