| &BCA7 | SOUND RESET |
| Action | Resets the sound manager by clearing the sound queues and abandoning any current sounds |
| Entry | No entry conditions |
| Exit | AF, BC, DE and HL are corrupt, and all others are preserved |
| &BCAA | SOUND QUEUE |
| Action | Adds a sound to the sound queue of a channel |
| Entry | HL contains the address of a series of bytes which define the sound and are stored in the central 32K of RAM |
| Exit | If the sound was successfully added to the queue, then Carry is true and HL is corrupt; if one of the sound queues was full, then Carry is false and HL is preserved; in either case, A, BC, DE, IX and the other flags are corrupt, and all others are preserved |
| Notes | The bytes required to define the sound are as follows byte 0 - channel status byte byte 1 - volume envelope to use byte 2 - tone envelope to use bytes 3&4 - tone period byte 5 - noise period byte 6 - start volume bytes 7&8 - duration of the sound, or envelope repeat count |
| &BCAD | SOUND CHECK |
| Action | Gets the status of a sound channel |
| Entry | A contains the channel to test - for channel A, bit 0 set; for channel B, bit 1 set; for channel C, bit 2 set |
| Exit | A contains the channel status, BC, DE, HL and flags are corrupt, and all others are preserved |
| Notes | The channel status returned is bit significant, as follows bits 0 to 2 - the number of free spaces in the sound queue bit 3 - trying to rendezvous with channel A bit 4 - trying to rendezvous with channel B bit 5 - trying to rendezvous with channel C bit 6 - holding the channel bit 7 - producing a sound |
| &BCB0 | SOUND ARM EVENT |
| Action | Sets up an event which will be activated when a space occurs in a sound queue |
| Entry | A contains the channel to set the event up for (see SOUND CHECK for the bit values this can take), and HL holds the address of the event block |
| Exit | AF, BC, DE and HL are corrupt, and all other registers are preserved |
| Notes | The event block must be initialised by KL INIT EVENT and is disarmed when the event itself is run |
| &BCB3 | SOUND RELEASE |
| Action | Allows the playing of sounds on specific channels that had been stopped by SOUND HOLD |
| Entry | A contains the sound channels to be released (see SOUND CHECK for the bit values this can take) |
| Exit | AF, BC, DE, HL and IX are corrupt, and all others are preserved |
| &BCB6 | SOUND HOLD |
| Action | Immediately stops all sound output (on all channels) |
| Entry | No entry conditions |
| Exit | If a sound was being made, then Carry is true; if no sound was being made, then Carry is false; in all cases, A, BC, HL and other flags are corrupt, and all others are preserved |
| Notes | When the sounds are restarted, they will begin from exactly the same place that they were stopped |
| &BCB9 | SOUND CONTINUE |
| Action | Restarts all sound output (on all channels) |
| Entry | No entry conditions |
| Exit | AF, BC, DE and IX are corrupt, and all others are preserved |
| &BCBC | SOUND AMPL ENVELOPE |
| Action | Sets up avolume envelope |
| Entry | A holds an envelope number (from 1 to 15), HL holds the address of a block of data for the envelope |
| Exit | If it was set up properly, Carry is true, HL holds the data block address + 16, A and BC are corrupt; if the envelope number is invalid, then Carry is false, and A, B and HL are preserved; in either case, DE and the other flags are corrupt, and all other registers are preserved |
| Notes | All the rules of enevelopes in BASIC also apply; the block of the data for the envelope is set up as follows byte 0 - number of sections in the envelope bytes 1 to 3 - first section of the envelope bytes 4 to 6 - second section of the envelope bytes 7 to 9 - third section of the envelope bytes 10 to 12 - fourth section of the envelope bytes 13 to 15 - fifth section of the envelope Each section of the envelope has three bytes set out as follows byte 0 - step count (with bit 7 set) byte 1 - step size byte 2 - pause time or if it is a hardware envelope, then each section takes the following form byte 0 - envelope shape (with bit 7 not set) bytes 1 and 2 - envelope period See also SOUND TONE ENVELOPE below |
| &BCBF | SOUND TONE ENVELOPE |
| Action | Sets up a tone envelope |
| Entry | A holds an envelope number (from 1 to 15), HL holds the address of a block of data for the envelope |
| Exit | If it was set up properly, Carry is true, HL holds the data block address + 16, A and BC are corrupt; ¡ if the envelope number is invalid, then Carry is false, and A, B and HL are preserved; in either case, DE and the other flags are corrupt, and all other registers are preserved |
| Notes | All the rules of envelopes in BASIC also apply; the block of the data for the envelope is set up as follows byte 0 - number of sections in the envelope bytes 1 to 3 - first section of the envelope bytes 4 to 6 - second section of the envelope bytes 7 to 9 - third section of the envelope bytes 10 to 12 - fourth section of the envelope bytes 13 to 15 - fifth section of the envelope Each section of the envelope has three bytes set out as follows byte 0 - step count byte 1 - step size byte 2 - pause time See also SOUND AMPL ENVELOPE above |
| &BCC2 | SOUND A ADDRESS |
| Action | Gets the address of the data block associated with a volume envelope |
| Entry | A contains an envelope number (from 1 to 15) |
| Exit | If it was found, then Carry is true, HL holds the data block's address, and BC holds its length; if the envelope number is invalid, then Carry is false, HL is corrupt and BC is preserved; in both cases, A and the other flags are corrupt, and all others are preserved |
| &BCC5 | SOUND T ADDRESS |
| Action | Gets the address of the data block associated with a tone envelope |
| Entry | A contains an envelope number (from 1 to 15) |
| Exit | If it was found, then Carry is true, HL holds the data block's address, and BC holds its length; if the envelope number is invalid, then Carry is false, HL is corrupt and BC is preserved; in both cases, A and the other flags are corrupt, and all others are preserved |