Difference between revisions of "SCUMM/NES"

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2,063 bytes removed ,  01:12, 7 April 2005
Sound is complete
(Sound is complete)
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=== Sound ===
=== Sound ===
* Sound - [http://qmt.ath.cx/~quietust/scumm/maniac/music.txt]
* Still need to link in an NES APU module to get sound output; otherwise, Player_NES is complete.
 
Sound Format:
uint16 length (added by extract util)
uint8 slot - specifies which slot the sound plays in - 2 for music, 0/1/4 for sound effects
- slot 4 sound effects appear to play in slot 0, but only if no music is playing?
uint8 type - 10 (0x0A) for sound effects, 100 (0x64) for music
uint8 data[]
 
Type 10 data:
[03/07/0B/0F] - next 4 bytes is data for sound channel 0/1/2/3 (square1, square2, triangle, noise)
[10] - next byte is a number of frames to wait before processing the next update
[FE] - loop back to beginning
[FF] - terminate sound
 
Type 100 data:
uint8 auxLen - specifies length of auxiliary data blocks
uint8 noteInstrs[auxLen] - Specifies the instrument of each predefined note
uint8 noteFreqs[auxLen] - Specifies the pitch of each predefined note
uint8 music[]:
00 thru (auxLen-1) - start playing a note using the specified instrument at the specified pitch
auxLen thru (auxLen+15) - update the note playing in the specified instrument (?)
(auxLen+16) thru 0xFF - delay N-auxLen-16 frames before parsing next byte
[FE] - loop back to beginning
[FF] - terminate sound
 
There are a total of 16 instruments, spread out over the 4 NES sound channels using the following mapping:
A total of 28 commands exist within the sound engine, each tied to one or more instruments.
Sound channels: (00 = square A, 01 = square B, 02 = triangle, 03 = noise)
* 00 00 00 00 00 00 00 01 01 01 02 02 01 03 03 03
Start commands:
* 05 03 06 08 0B 01 01 1A 16 06 04 17 02 10 0E 0D
Update (?) commands:
* 0F 00 00 09 00 14 15 00 00 00 1B 1B 0F 0F 0F 0F
To make matters worse, each command automatically chains to another after a set number of frames:
00 -> xx
01 -> xx
02 -> xx
03 -> xx
04 -> 17 (3)
05 -> xx
06 -> 07 (3)
07 -> xx
08 -> xx
09 -> 0A (5)
0A -> 09 (8)
0B -> 0C (3)
0C -> 00 (0?)
0D -> 00 (0?)
0E -> 00 (0)
0F -> 00 (0)
10 -> 11 (2)
11 -> 12 (2)
12 -> 11 (2)
13 -> 03 (0)?
14 -> xx
15 -> xx
16 -> 18 (3)
17 -> 00 (0)?
18 -> 19 (3)
19 -> 00 (0)?
1A -> 00 (0)?
1B -> 00 (0)?
 
Behavior of each command has not yet been determined
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