The soundData variable - The Sentinel on the BBC Micro

       Name: soundData                                               [Show more]
       Type: Variable
   Category: Sound
    Summary: OSWORD blocks for making the various game sounds
    Context: See this variable in context in the source code
 References: This variable is used as follows:
             * GetPlayerDrain uses soundData
             * MakeSound uses soundData
             * MakeSoundEnvelope uses soundData
             * ProcessActionKeys (Part 2 of 2) uses soundData
             * ProcessMusic uses soundData
             * ProcessSound uses soundData


 Sound data. To make a sound, the MakeSound routine passes the bytes in this
 table to OSWORD 7. These bytes are the OSWORD equivalents of the parameters
 passed to the SOUND keyword in BASIC. The parameters have these meanings:

   channel/flush, amplitude (or envelope number if 1-4), pitch, duration

 where each value consists of two bytes, with the low byte first and the high
 byte second.

 For the channel/flush parameter, the top nibble of the low byte is the flush
 control (where a flush control of 0 queues the sound, and a flush control of
 1 makes the sound instantly), while the bottom nibble of the low byte is the
 channel number. When written in hexadecimal, the first figure gives the flush
 control, while the second is the channel (so &13 indicates flush control = 1
 and channel = 3).


.soundData

 EQUB &10, &00          \ Sound data block #0: SOUND &10, 1, 7, 5
 EQUB &01, &00          \
 EQUB &07, &00          \ Used for the first part of sounds #0 (rotating enemy),
 EQUB &05, &00          \ #1 (rotating meanie) and #6 (game over)

 EQUB &11, &00          \ Sound data block #1: SOUND &11, 0, 120, 10
 EQUB &00, &00          \
 EQUB &78, &00          \ Used for the second part of sounds #0 (rotating
 EQUB &0A, &00          \ enemy), #1 (rotating meanie) and #6 (game over)

 EQUB &12, &00          \ Sound data block #2: SOUND &12, 3, 34, 20
 EQUB &03, &00          \
 EQUB &22, &00          \ Used for sounds #3 (music) and #4 (scanner)
 EQUB &14, &00

 EQUB &13, &00          \ Sound data block #3: SOUND &13, 4, 144, 20
 EQUB &04, &00          \
 EQUB &90, &00          \ Used for sound #5 (ping)
 EQUB &14, &00

 EQUB &10, &00          \ Sound data block #4: SOUND &10, 2, 4, 40
 EQUB &02, &00          \
 EQUB &04, &00          \ Used for sound #2 (create/absorb object white noise)
 EQUB &28, &00
Sound: soundData
