David Whittaker Sound Engine

David Whittaker Sound Engine is a sound driver for the SPC700 programmed by David Whittaker.

Many games have multiple different builds stored in the game at once, sometimes with code differences. Almost every single game has at least one unique build not shared by any of the other games: the exceptions are...

• The opening logos for Lemmings 2: The Tribes and Apocalypse II
• Kick Off 3 Beta's Title Screen and Lawnmower Man/Virtual Wars' US Beta

These are the games where the sound engine was used:

Game Name	Music Version	VCMD Code Location	ROM Offset
Dream TV	0.0 (Beta 2) 2.0 (all other versions)	0x098A (Beta 2) 0x0614 (all other versions)	0x0196A2 (Beta 2, uncompressed) 0x039B16 (all other versions, RNC compressed)
Krusty's Super Fun House	1.0	0x04F1	0x0E8000 (all versions)
Kick Off/Super Kick Off	1.0	0x04E6	0x098000 (all versions)
Batman: Revenge of the Joker	2.0	0x0610	0x068000
Super SWIV/Firepower 2000	2.1	0x06AD	0x158000
Gods	2.2	0x0500/0x0600/0x0612	0x980000/0x98AFAC/0x99D448/0x9A8000 (all versions, three unique build variants, RNC compressed)
World Class Rugby	2.2	0x0608	0x0B8000 (all versions)
Battle Cars	3.0	0x0717	0x0A8000
Chavez/Riddick Bowe Boxing	3.0 (all other versions) 3.1 (Japanese version)	0x0621 (Japanese version) 0x067C (US version) 0x067D (Chavez)	0x0D8000 (all versions)/0x0E8000 (all versions except Chavez) (three unique build variants, one per version between Chavez, US & Japanese versions)
Lawnmower Man/Virtual Wars	3.1	0x06BD (US beta) 0x06A4 (all other versions)	0x9C8000 (all versions except US beta)/0x9E8000 (all versions)
Apocalypse II	3.1	0x05AF/0x0624	0x118000/0x168000
Elite Soccer/World Cup Striker	3.1	0x0601 (US and European version In-Game) 0x060B (US and Japanese version Title Screen) 0x0704 (Japanese version In-Game) 0x070B (European version Title Screen)	0x1B8000 (all versions)/0x08D500 (US & Japanese version)/0x08D550 (European beta version)/0x08D640 (European version) (Four unique build variants: two Title Screen (US/JP compared to EU) and two In-Game (US/EU compare to JP))
Kick Off 3 (Beta version only)	3.1	0x0658/0x06BD	0x1A8000/0x1D8000
Lemmings 2: The Tribes	3.1	0x05AF/0x060F/0x0614/0x0621/0x0697	(omitted for now: there are 16 copies of the code in the ROM, with five different build variants being present: four of them are used in one instance each, that being the opening logo, the Title Screen, the Beach Tribe and the Cavelem Tribe, and the others use a single common copy of the code with modifications of constants and non-code pointers)
Porky Pig's Haunted Holiday (Beta version only)	3.1	0x06CA	(omitted for now: there are 36 copies of the code in the ROM, none of which are unique except for the sound data and modifications of constants and non-code pointers)
Shaq Fu	4.0a	0x0539	0xD96408 (all versions)
Michael Jordan: Chaos in the Windy City	4.0b	0x0539	0xD2B18F (all versions)

Song Entry

For each song entry in an array of song definitions, one byte is defined as a starting tempo, followed by a series of pointers defined little endian style for each channel. For Dream TV Beta and Kick Off, only five pointers are defined. For Krusty's Super Fun House, only six pointers are defined. For all other games, eight pointers are defined.

xx yy yy zz zz aa aa bb bb cc cc dd dd ee ee ff ff

• xx is the starting tempo.
• yy yy is a little-endian pointer to a pattern order list for channel 1.
• zz zz is a little-endian pointer to a pattern order list for channel 2.
• aa aa is a little-endian pointer to a pattern order list for channel 3.
• bb bb is a little-endian pointer to a pattern order list for channel 4.
• cc cc is a little-endian pointer to a pattern order list for channel 5.
• dd dd is a little-endian pointer to a pattern order list for channel 6. (Krusty's Super Fun House only pre-V2.0)
• ee ee is a little-endian pointer to a pattern order list for channel 7. (not supported pre-V2.0)
• ff ff is a little-endian pointer to a pattern order list for channel 8. (not supported pre-V2.0)

Two builds don't support song entries at all:

• The opening logos for Lemmings 2: The Tribes and Apocalypse II
• Kick Off 3 Beta (In-Game)

Pattern Order List

Each track has a list of pointers on a per-track basis. If the pointer is zero, then you jump back to the beginning of the pattern order list for that track.

Instrument Format

The instrument format at V0.0 is N-SPC/Kankichi-kun compatible minus noise support for SRCN values above 127. Post V1.0, one of the bytes loses its usage.

The instrument format is defined as direct writes to DSP registers for the first four bytes, followed by two pitch-related bytes. They are defined in this order, from top to bottom...

• SRCN
• ADSR1
• ADSR2
• GAIN (unused byte post-V2.0)
• Pitch Base Multiplier
• Pitch Base Fractional Multiplier (in 256ths)

Voice Command Format

VCMD ID	Description	Arguments	Minimum Version
$00-$5F	Note		0.0
$60-$7F	Note Length		0.0
$80-$EC	Invalid		0.0
$ED	Instant Pitch Change to Note	xx	4.0a only
$ED	Set Master Volume	xx	4.0b only
$EE	Volume Scaler by Fraction	xx yy	3.0
$EF	Set ADSR	xx yy	2.0
$F0	Fine Tune	xx	1.0
$F1	Pitch Bend	xx	1.0
$F2	Pitch Envelope ID	xx	0.0
$F3	L/R Voice Volume	xx yy	0.0
$F4	Tempo	xx	0.0
$F5	Jump to Pattern in Order List	xx xx	0.0
$F6	Invalid		0.0
$F7	Invalid		0.0
$F8	Key Off		0.0
$F9	One Note Delay		0.0
$FA	Instrument	xx	0.0
$FB	Absolute Global Transposition	xx	0.0
$FC	Absolute Transposition	xx	0.0
$FD	Invalid		0.0
$FE	Song End		0.0
$FF	Pattern End		0.0

Invalid (VCMDs $80-$EC, $F6-$F7, $FD, $ED (pre-V4.0), $EE (pre-V3.0), $EF (pre-V2.0), $F0-$F1 (pre-V1.0))

The sound driver deliberately freezes itself via an infinite branch always loop rather than crashing or skipping the byte. This also takes up VCMD slots that are not filled in earlier versions.

Work in Progress... TODO...

• Voice Command Format