EarthBound Beginnings Music Format Addendum.txt

EARTHBOUND BEGINNINGS MUSIC FORMAT ADDENDUM
v0.2

By Justin Olbrantz (Quantam)

The permanent home of this specification and others, with the latest updates, is https://github.com/TheRealQuantam/RetroDocs.

This document is an addendum to the Mother Music Format specification. While that specification was based on the Japanese original, this addendum covers EarthBound Beginnings, the official English version on the Virtual Console which is identical to the older leaked English prototype commonly known as EarthBound Zero. For the most part the audio systems of the Japanese and English versions are identical (apart from things being at different addresses), though the English version has a couple noteworthy differences.

EBB is a throwback to the bad old days of Metroid, where music code and data is duplicated in multiple ROM banks (not to be confused with track banks), though unlike Metroid in EBB the code and data do NOT have the same addresses across banks, nor are they entirely identical. EBB adds 3 new tracks to the game: 1 track resembling Giegue's Cry of unknown usage and 2 tracks that make up the new ending to the game, replacing the ending music of the original. Apparently this new ending required a new ROM bank, resulting in all the music code and global data being copied to it; however, the 2 ROM banks have completely unique music tracks and different note length and volume envelope tables. Confusingly, while 2 of the 3 new tracks are assigned the unique track numbers $32 and $33, the third is assigned to EVERY track number in the ending ROM bank from 1-$31 (the numbers of the original Mother tracks found in the other bank); for clarity let's call this "track X".

In an attempt to cut down on confusion, this document is divided into 2 halves: Normal Music and Ending Music. My hope is that explicitly separating the 2 copies of all the structures will minimize the chance of confusing addresses between the 2 banks.

NORMAL MUSIC

The normal music bank holds all of the original Mother music plus 1 new track and 1 new envelope. All the other data is identical to Mother, but the locations in the ROM are different.

Bank Configuration:
$8000-$9fff: Bank $1c
$a000-$bfff: Bank $1d

File offsets = address + $30010.

1c:9074 byte[$68?]: Note length table in frames

Code to load the current length for notes:
8D42    LDA $9074,Y

Code to limit the triangle auto-release length to 15 frames ($3c quarter-frames) when in dynamic auto-release mode:
8E0B    CMP #$3C
8E0D    BCC $8E11
8E0F    LDA #$3C

1c:8fea big-endian word[$43]: Key pitch table, in period register units. For square wave channels, period = 1789773 / frequency / 16 - 1 (triangle channel is 1 octave lower). Entry 1 must be 0 as it is rest.

Code to load the period for a melodic key:
8D5E    LDA $8FEB,Y
...
8D79    LDA $8FEB,Y
8D7C    STA $0780,X
8D7F    LDA $8FEA,Y
8D82    ORA #$08
8D84    STA $0781,X

1c:89a7 byte[$1f?]: Noise presets table. Data actually starts at offset 1 ($89a8), and is NOT an array, as some entries overlap. The first byte should always be $10 as preset 1 is rest.

Code to play a noise preset:
8E2B    LDA $89A7,Y
8E2E    STA NoiseVolume_400C
8E31    LDA $89A8,Y
8E34    STA NoisePeriod_400E
8E37    LDA $89A9,Y
8E3A    STA NoiseLength_400F

Code to play a DMC preset if any:
8E3E    TYA
8E3F    AND #$C0
8E41    CMP #$40
8E43    BEQ $8E4A
8E45    CMP #$80
8E47    BEQ $8E54
8E49    RTS
8E4A    LDA #$0E
8E4C    STA $B1
8E4E    LDA #$07
8E50    LDY #$00
8E52    BEQ $8E5C
8E54    LDA #$0E
8E56    STA $B1
8E58    LDA #$0F
8E5A    LDY #$02
8E5C    STA DmcLength_4013
8E5F    STY DmcAddress_4012
8E62    LDA $07F7
8E65    BNE $8E7B
8E67    LDA $B1
8E69    STA DmcFreq_4010
8E6C    LDA #$0F
8E6E    STA ApuStatus_4015
8E71    LDA #$00
8E73    STA DmcCounter_4011
8E76    LDA #$1F
8E78    STA ApuStatus_4015
8E7B    RTS

1c:8e85 word[$1c]: Volume envelope table. Indices are 0-based, unlike in the set timbre commands and the following table. The first $1b envelopes are identical to those in Mother, but are repeated here for convenience; however, EBB has 1 additional envelope not found in Mother, used by the new track.

Envelope  1 @8ee9: 233456776554 ff
Envelope  2 @8ef0: 5a9888776666655555 ff
Envelope  3 @8f14: 111122223333444444455555556666777888 ff
Envelope  4 @8f27: f987777766655544 ff
Envelope  5 @8f30: a876 ff
Envelope  6 @8f36: 99 ff
Envelope  7 @8ee2: 235678888887 ff
Envelope  8 @8f38: dcba998887765544 ff
Envelope  9 @8f41: 2344333333333332 ff
Envelope  a @8f33: 7432 ff
Envelope  b @8f4a: 7776655544433221 f0
Envelope  c @8f53: 44433332221111 f0
Envelope  d @8f5b: 33332222111111 f0
Envelope  e @8f63: 222222111111 f0
Envelope  f @8f6a: 1111111111110100 f0
Envelope 10 @8f73: 998877766655544433333332222222222111111111111111 f0
Envelope 11 @8fbe: 23455544333322 ff
Envelope 12 @8fc6: 87654321443321113221111121111111111111 ff
Envelope 13 @8f8c: 6555544433333333222222221111111111111111 f0
Envelope 14 @8fda: 666542213221111121111111111111 ff
Envelope 15 @8fa1: fbbaaa99999998887777776666665554444443333322222222111111 f0
Envelope 16 @8ebd: 7611111431 ff
Envelope 17 @8efa: 111122223333444444455555556666777888765432 ff
Envelope 18 @8ed9: 9876632287765311 f0
Envelope 19 @8ed2: 233332222222 ff
Envelope 1a @8ec7: 91919191919191919191 f0
Envelope 1b @8ec3: 334566 ff
Envelope 1c @8f10: 111122 ff

Code to load a volume envelope address:
8BC0    LDA $8E85,Y
8BC3    STA $B2
8BC5    LDA $8E86,Y
8BC8    STA $B3

EBB has the same set of pitch envelopes as Mother:
89F6    LDA $B2
89F8    CMP #$31
89FA    BNE $89FE
89FC    LDA #$27
89FE    TAY
89FF    LDA $8A85,Y
8A02    PHA
8A03    LDA $07C3,X
8A06    CMP #$46
8A08    BNE $8A0F
8A0A    PLA
8A0B    LDA #$00
8A0D    BEQ $8A6D
8A0F    PLA
8A10    JMP $8A6D
8A13    LDA $B2
8A15    TAY
8A16    CMP #$10
8A18    BCS $8A20
8A1A    LDA $8ABC,Y
8A1D    JMP $8A73
8A20    LDA #$F6
8A22    BNE $8A73
8A24    LDA $07C3,X
8A27    CMP #$4C
8A29    BCC $8A2F
8A2B    LDA #$FE
8A2D    BNE $8A73
8A2F    LDA #$FE
8A31    BNE $8A73
...
8A33    LDA $07D1,X <- starts here
8A36    STA $B2
8A38    LDA $B0
8A3A    CMP #$20
8A3C    BEQ $8A52
8A3E    CMP #$A0
8A40    BEQ $8A61
8A42    CMP #$60
8A44    BEQ $8A24
8A46    CMP #$40
8A48    BEQ $8A13
8A4A    CMP #$80
8A4C    BEQ $89F6
8A4E    CMP #$C0
8A50    BEQ $89F6
8A52    LDA $B2
8A54    CMP #$0A
8A56    BNE $8A5A
8A58    LDA #$00
8A5A    TAY
8A5B    LDA $8AB2,Y
8A5E    JMP $8A6D
8A61    LDA $B2
8A63    CMP #$2B
8A65    BNE $8A69
8A67    LDA #$21
8A69    TAY
8A6A    LDA $8A91,Y
8A6D    PHA
8A6E    TYA
8A6F    STA $07D1,X
8A72    PLA
8A73    PHA
8A74    LDA $07C8,X
8A77    BNE $8A83
8A79    PLA
8A7A    CLC
8A7B    ADC $B1
8A7D    LDY $BE
8A7F    STA Sq0Timer_4002,Y
8A82    RTS
8A83    PLA
8A84    RTS

The code that determines whether a given envelope has the triangle "forever" flag set:
8DF4    LDA $079C
8DF7    AND #$C0
8DF9    BNE $8DFE
8DFB    TYA
8DFC    BNE $8E06
8DFE    CMP #$C0
8E00    BEQ $8DFB
8E02    LDA #$FF

1c:90dc byte[$18]: Low track header offset table. Indices are actually 0-based, unlike the numbers given.
1c:90f4 byte[$19]: High track header offset table
1c:910e struct[$18]: Low track header block
1c:91fe struct[$19]: High track header block
1c:92f8 struct: Track $32 header

Track bank 0: Header offset table 90dc, header block base 910e:
   1 Eight Melodies @910e:  +24  +18  ffff  ffff   76c  ffff
    Triangle @ 76c: 9353 935a 9365 9370 937c 9388 9391 939e 93aa 0000

   2 Battle Theme 1 @9118:   +0  +28  93b2  93ba  93c4  93d6
    Square 1 @93b2: 963b | 93de
    Square 2 @93ba: 964d | 94b4 94f7
    Triangle @93c4: 965f | 9590 95a2 9590 9590 95a2 95d3
    Noise    @93d6: 9671 | 95ec

   3 Battle Theme 2 @9122:   +0  +28  9617  9621  962b  9633
    Square 1 @9617: 963b | 9674 96b6
    Square 2 @9621: 964d | 9695 975a
    Triangle @962b: 965f | 97c8
    Noise    @9633: 9671 | 9823

   4 Battle Theme 3 @912c:   +0  +28  9847  9851  985b  9867
    Square 1 @9847: 963b | 9871 98a9
    Square 2 @9851: 964d | 98bd 993e
    Triangle @985b: 965f | 9988 99a7 999c
    Noise    @9867: 9671 | 99d4 99d4

   5 Victory @9136:   +0   +0  9a03  9a07  9a09  ffff
    Square 1 @9a03: 9a0b 0000
    Square 2 @9a07: 9a1a
    Triangle @9a09: 9a29

   6 Pollyanna (I Believe in You) @914a:   +0  +35  9bb7  9bc1  9bcb  9bd3
    Square 1 @9bb7: 9bdb | 9c54 9c98
    Square 2 @9bc1: 9bfc | 9d3f 9d76
    Triangle @9bcb: 9c1d | 9dae
    Noise    @9bd3: 9c35 | 9ce8

   7 Bein' Friends @9140:   +0  +28  9e2d  9e39  9e45  9e51
    Square 1 @9e2d: | 9e5d 9ed2 9ed2 9f6b
    Square 2 @9e39: | 9e84 9ef7 9ef7 9fc0
    Triangle @9e45: | 9eb0 9f1b 9f1b a003
    Noise    @9e51: | 9ebe 9f57 9f57 a054

   8 Advent Desert @9154:   -2   +c  9a38  9a40  9a48  9a50
    Square 1 @9a38: 9a58 | 9a74
    Square 2 @9a40: 9a61 | 9ae6
    Triangle @9a48: 9a6a | 9b93
    Noise    @9a50: 9a70 | 9bac

   9 Magicant @915e:   +0  +4c  a12c  a134  a13a  a148
    Square 1 @a12c: a14e | a158
    Square 2 @a134: | a155
    Triangle @a13a: | a1c4 a1d0 a1e1 a1e1 a1f2
    Noise    @a148: | a20a

   a Snow Man @9168:   +0  +35  a21a  a230  a236  ffff
    Square 1 @a21a: a2a6 | a2b0 a2d5 a2b0 a2fd a31b a335 a31b a349
    Square 2 @a230: a2ac ffff a21c
    Square 2 @a21c: | a2b0 a2d5 a2b0 a2fd a31b a335 a31b a349
    Triangle @a236: | a240 a240 a279

   b Mount Itoi @9172:   +0  +4c  a36d  a373  a379  a37f
    Square 1 @a36d: | a385
    Square 2 @a373: | a39f
    Triangle @a379: | a3e8
    Noise    @a37f: | a416

   c Factory @917c:   +0  +35  a737  a72f  a741  a749
    Square 1 @a737: a7b0 | a75a a79d
    Square 2 @a72f: | a757 a79a
    Triangle @a741: | a7b6 a7bf
    Noise    @a749: | a7d3 a7e6 a7f8 a7e6 a7fe

   d South Cemetery @9186:   +0  +35  a425  a42d  a435  a43d
    Square 1 @a425: a445 | a4a6
    Square 2 @a42d: a45d | a4a3
    Triangle @a435: a478 | a4ec
    Noise    @a43d: a48b | a516

   e Twinkle Elementary School @9190:   +0  +18  a529  a52f  a535  a53b
    Square 1 @a529: | a541
    Square 2 @a52f: | a585
    Triangle @a535: | a5b1
    Noise    @a53b: | a5d7

   f Humoresque of a Little Dog @919a:   +0  +18  a60e  a616  a61c  a622
    Square 1 @a60e: a6ca | a62b
    Square 2 @a616: | a628
    Triangle @a61c: | a6d0
    Noise    @a622: | a708

  10 Poltergeist @91a4:   -8  +18  a083  a08d  a097  a0a1
    Square 1 @a083: a0a9 | a0ae a0c4
    Square 2 @a08d: a0cc | a0cc a0e7
    Triangle @a097: a0ef | a0fa a108
    Noise    @a0a1: a111 | ae06

  11 Basement @91ae:   +0  +28  a811  a819  a825  a82d
    Square 1 @a811: a835 | a85a
    Square 2 @a819: a840 | a867 a85d a88a
    Triangle @a825: a84b | a895
    Noise    @a82d: a855 | a8ac

  12 My Home @91b8:   +2  +43  a995  a98f  a99b  a9a1
    Square 1 @a995: | a9e2
    Square 2 @a98f: | a9ac
    Triangle @a99b: | aa02
    Noise    @a9a1: | a9a7

  13 Cave 2 @91c2:   +0  +35  aa1c  aa26  aa2e  aa36
    Square 1 @aa1c: aa5a aab3 | aabb
    Square 2 @aa26: aa3e | aa98
    Triangle @aa2e: aa73 | aad3
    Noise    @aa36: aa8b | aaf5

  14 The Paradise Line @91cc:   +0  +18  bc45  bc59  bc65  bc79
    Square 1 @bc45: bc81 | bd2a bd2a bd3e bd2a bd2a bd3e bd51
    Square 2 @bc59: bcae | bd9b bd9b bdf9
    Triangle @bc65: bccf | be43 be43 be51 be43 be43 be51 be5b
    Noise    @bc79: bcfc | be7c

  15 Fallin' Love @91d6:   +0  +43  ab1e  ab2c  ab36  ab3c
    Square 1 @ab1e: | ab66 ab6e ab6a ab6e ab50
    Square 2 @ab2c: ab42 | ab46 ab7d
    Triangle @ab36: | abb5
    Noise    @ab3c: | abc4

  16 Mother Earth @91e0:   +0  +28  bb29  bb23  bb2f  bb35
    Square 1 @bb29: | bb92
    Square 2 @bb23: | bb3b
    Triangle @bb2f: | bc0d
    Noise    @bb35: | bc3f

  17 Tank @91ea:   +0  +18  abe0  abf0  abfe  ac06
    Square 1 @abe0: | ac77 ac7f ac7f ac91 acec ac23
    Square 2 @abf0: | acb3 acbb acbb accd ac0e
    Triangle @abfe: | ad9c ac3e
    Noise    @ac06: | ade6 ac5b

  18 Ruins of Desert @91f4:   +0   +c  a8b5  a8bd  a8c3  ffff
    Square 1 @a8b5: | a8c9 a8d0
    Square 2 @a8bd: | a8cd
    Triangle @a8c3: | a93b

Track bank 1: Header offset table 90f4, header block base 91fe:
  19 Queen Mary's Song @91fe:   +0  +28  ae84  ae6c  ffff  ffff
    Square 1 @ae84: ae8e ffff ae6e
    Square 1 @ae6e: | 935a 9365 9370 937c 9388 9391 939e 93aa ae8a
    Square 2 @ae6c: ae94 | 935a 9365 9370 937c 9388 9391 939e 93aa ae8a

  1a Wisdom of the World @9208:   +0  +5a  aefb  af01  af07  ffff
    Square 1 @aefb: | af0d
    Square 2 @af01: | af69
    Triangle @af07: | afca

  1b Tombstone @9212:  +24  +4c  afff  aff7  ffff  ffff
    Square 1 @afff: b00b | 9d42
    Square 2 @aff7: | b007 9d42

  1c Game Over @921c:   +0  +4c  b012  b01a  b022  ffff
    Square 1 @b012: b026 b02f ffff b01c
    Square 1 @b01c: | b039
    Square 2 @b01a: b02c | b039
    Triangle @b022: b049 0000

  1d Big Victory @9226:   +0  +18  b061  b065  b067  ffff
    Square 1 @b061: b069 0000
    Square 2 @b065: b07b
    Triangle @b067: b08f

  1e Airplane @9230:   +0  +18  b992  b998  b99e  b9b0
    Square 1 @b992: | b9b8
    Square 2 @b998: | b9f8
    Triangle @b99e: | ba43 ba73 ba73 bae3 bb00 bae3 bb0a
    Noise    @b9b0: | ba82 baa6

  1f Level Up @923a:   +6   +0  aec7  aed1  aed9  ffff
    Square 1 @aec7: b069 aee1 | aeec
    Square 2 @aed1: b07b | aee9
    Triangle @aed9: b08f | aef8

  20 Recovery @9244:   -4  +18  ae98  ae9c  ae9e  ffff
    Square 1 @ae98: aea0 0000
    Square 2 @ae9c: aead
    Triangle @ae9e: aeb9

  21 Fanfare @924e:   -4  +43  b438  b43c  b43e  ffff
    Square 1 @b438: b44c 0000
    Square 2 @b43c: b440
    Triangle @b43e: b459

  22 Live House @9258:   -8  +18  b09e  b0a4  b0b0  b0bc
    Square 1 @b09e: | b0c2
    Square 2 @b0a4: | b0de b0de b0f4 b0de
    Triangle @b0b0: | b107 b107 b11b b107
    Noise    @b0bc: | b12c

  23 All That I Needed (Was You) @9262:   +0  +18  b13c  b152  b162  b174
    Square 1 @b13c: b1df b1f3 b1f3 b238 b243 b243 b243 b268 b1f3 b238 b178 b1c8
    Square 2 @b152: b1c8 b295 b2cf b295 b2d2 b295 b18c 0000
    Triangle @b162: b1eb b340 b340 b35d b360 b360 b36d b340 b1b5
    Noise    @b174: b384 b3ab

  24 Melody 1 - Doll @926c:  +48  +28  9302  9306  ffff  ffff
    Square 1 @9302: 9347 935a
    Square 2 @9306: 9357 0000

  25 Melody 2 - Canary @9276:  +24  +28  930a  930e  ffff  ffff
    Square 1 @930a: 934d 9365
    Square 2 @930e: 9362 0000

  26 Melody 3 - Monkey @9280:   +0  +28  9312  9316  ffff  ffff
    Square 1 @9312: 934d 9370
    Square 2 @9316: 936d 0000

  27 Melody 4 - Piano @928a:   +0  +28  931a  931e  ffff  ffff
    Square 1 @931a: 9347 937c
    Square 2 @931e: 9379 0000

  28 Melody 5 - Cactus @9294:  +48  +28  9322  9326  ffff  ffff
    Square 1 @9322: 934d 9388
    Square 2 @9326: 9385 0000

  29 Melody 6 - Dragon @929e:  +24  +28  932a  932e  ffff  ffff
    Square 1 @932a: 934d 9391
    Square 2 @932e: 938e 0000

  2a Melody 7 - EVE @92a8:  +48  +28  9332  9336  ffff  ffff
    Square 1 @9332: 9347 939e
    Square 2 @9336: 939b 0000

  2b Melody 8 - Tombstone @92b2:  +24  +28  933a  933e  ffff  ffff
    Square 1 @933a: 934d 93aa
    Square 2 @933e: 93a7 0000

  2c Giegue @92bc:   +0  +43  b461  b467  ffff  ffff
    Square 1 @b461: | b46d
    Square 2 @b467: | b473

  2d Mother Ending @92c6:   +0  +28  b825  b817  b839  b847
    Square 1 @b825: b644 b896 b5e1 b6e6 b72c b78a b602 | b644
    Square 2 @b817: b605 b855 b5cb b693 | b605
    Triangle @b839: b689 b964 b5f8 b7a0 | b689
    Noise    @b847: b68e b988 b5fd b7e7 | b68e

  2e Choucream Zoo @92d0:   +0  +28  b479  b47f  a827  a82f
    Square 1 @b479: | b485
    Square 2 @b47f: | b48d
    Triangle @a827: | a895
    Noise    @a82f: | a8ac

  2f Phone @92da:   +0  +18  ffff  b495  ffff  ffff
    Square 2 @b495: | b49b

  30 Youngtown @92e4:   +0  +28  b4a3  b4a9  b4af  ffff
    Square 1 @b4a3: | b4bb
    Square 2 @b4a9: | b4e7
    Triangle @b4af: | b51c

  31 Cave 1 @92ee:   +0  +28  b556  b55e  ffff  ffff
    Square 1 @b556: b564 | b56d
    Square 2 @b55e: | b56a

Track 1 (Eight Melodies) functions the same as it did in Mother:

1c:80e6 word[$a]: Base (0 melodies) track 1 triangle playlist
1c:8238 word[8]: Full (8 melodies) track 1 triangle playlist entries 1-8

The code to update the playlist based on the currently acquired melodies:
8248    LDA $761E
824B    STA $B0
824D    LDY #$00
824F    BEQ $825D
8251    LDA #$42
8253    STA $076E,Y
8256    INY
8257    LDA #$93
8259    STA $076E,Y
825C    INY
825D    TYA
825E    CMP #$10
8260    BEQ $8276
8262    LSR $B0
8264    BCC $8251
8266    LDA $8238,Y
8269    STA $076E,Y
826C    INY
826D    LDA $8238,Y
8270    STA $076E,Y
8273    INY
8274    BNE $825D
8276    RTS

The code to never use pitch envelopes on track 1:
89CC    LDA $07FD
89CF    CMP #$01
89D1    BEQ $89F5

There is a very slight difference in block $ba43 of track $1e (Airplane): 2 E2 half notes were fused into a single whole note. As this is on the triangle channel and auto-release is disabled, this is probably inaudible.

  32 Unknown @92f8:   +0  +43  b580  b588  b590  b596
    Square 1 @b580: b59c | b59f
    Square 2 @b588: b5a3 | b5a6
    Triangle @b590: | b5aa
    Noise    @b596: | b5bc

Track $32 is unique to EBB. Although this track's header comes immediately after track $31's and could barely have fit in bank 1, it is not present in the header offset table and is hard-coded in the BeginTrack function:
8AF4    CMP #$32
8AF6    BEQ $8B06
...
8B06    LDX #$00
8B08    LDY #$00
8B0A    LDA $92F8,Y
8B0D    STA $0790,X
8B10    INY
8B11    INX
8B12    TXA
8B13    CMP #$0A
8B15    BNE $8B0A

Code to load a bank 0 track header:
8B1E    LDA $90DC,Y
8B21    TAY
8B22    LDX #$00
8B24    LDA $910E,Y
8B27    STA $0790,X
8B2A    INY
8B2B    INX
8B2C    TXA
8B2D    CMP #$0A
8B2F    BNE $8B24

Code to load a bank 1 track header:
8AD0    LDA $90F4,Y
8AD3    TAY
8AD4    LDX #$00
8AD6    LDA $91FE,Y
8AD9    STA $0790,X
8ADC    INY
8ADD    INX
8ADE    TXA
8ADF    CMP #$0A
8AE1    BNE $8AD6

ENDING MUSIC

The ending music ROM bank holds only the 2 tracks used in the ending, and does not duplicate the tracks of the normal bank. Although the ending music bank also has low and high music banks, all entries in these banks (1-$31) point to track X.

Bank Configuration:
$8000-$9fff: Bank $1b. File offsets = address + $2e010.
$a000-$bfff: Bank $1d. File offsets = address + $30010.

1b:891a byte[$75?]: Note length table in frames. Adds in 120 BPM, causing the base offsets of subsequent tempos to shift.

          0   1   2   3    4   5    6   7   8    9   a  b  c   d  e    f
    BPM  16   8   4   2    1  4D   2D  8D  4T   8T  32
0  (225): 4   8  16  32   64  24   48  12  10*   5*  2  1
c  (180): 5  10  20  40   80  30   60  15  12*   6*  3* 2
18 (150): 6  12  24  48   96  36   72  18  16    8   3  1  4   2  0  144
28 (129): 7  14  28  56  112  42   84  21  18*   9*  3* 1  2
35 (120): 7* 15  30  60  120  45   90  22* 20   10   3* 1  8
42 (113): 8  16  32  64  128  48   96  24  21*  10*  4  1  2 192
50 (100): 9  18  36  72  144  54  108  27  24     *   *
59 (90): 10  20  40  80  160  60  120  30  26*  13*  5  1  2  23
67 (82): 11  22  44  88  176  66  132  33  29*  14*  5* 1  2  23

Code to load the current length for notes:
8597    LDA $891A,Y

Code to limit the triangle auto-release length to 15 frames ($3c quarter-frames) when in dynamic auto-release mode:
8660    CMP #$3C
8662    BCC $8666
8664    LDA #$3C

1b:8890 big-endian word[$43]: Key pitch table, in period register units. Identical to the normal tracks table.

Code to load the period for a melodic key:
85B8    LDA $0790
...
85D1    STA $0780,X
85D4    LDA $8890,Y
85D7    ORA #$08
85D9    STA $0781,X

1b:81f0 byte[$1f?]: Noise presets table. Identical to the normal tracks table.

Code to play a noise preset:
8680    LDA $81F0,Y
8683    STA NoiseVolume_400C
8686    LDA $81F1,Y
8689    STA NoisePeriod_400E
868C    LDA $81F2,Y
868F    STA NoiseLength_400F

Code to play a DMC preset if any:
8693    TYA
8694    AND #$C0
8696    CMP #$40
8698    BEQ $869F
869A    CMP #$80
869C    BEQ $86A9
869E    RTS
869F    LDA #$0E
86A1    STA $B1
86A3    LDA #$07
86A5    LDY #$00
86A7    BEQ $86B1
86A9    LDA #$0E
86AB    STA $B1
86AD    LDA #$0F
86AF    LDY #$02
86B1    STA DmcLength_4013
86B4    STY DmcAddress_4012
86B7    LDA $07F7
86BA    BNE $86D0
86BC    LDA $B1
86BE    STA DmcFreq_4010
86C1    LDA #$0F
86C3    STA ApuStatus_4015
86C6    LDA #$00
86C8    STA DmcCounter_4011
86CB    LDA #$1F
86CD    STA ApuStatus_4015
86D0    RTS

1b:86da word[$1e]: Volume envelope table. Envelopes $b-$f and $1a are different than for normal tracks, and $1d-$1e are new.

Envelope  1 @874c: 233456776554 ff
Envelope  2 @8753: 5a9888776666655555 ff
Envelope  3 @8777: 111122223333444444455555556666777888 ff
Envelope  4 @878a: f987777766655544 ff
Envelope  5 @879c: a876 ff
Envelope  6 @87a2: 99 ff
Envelope  7 @8745: 235678888887 ff
Envelope  8 @87a4: dcba998887765544 ff
Envelope  9 @87ad: 2344333333333332 ff
Envelope  a @879f: 7432 ff
Envelope  b @87b6: 777665554443322211111111 f0
Envelope  c @87c3: 54433333322222111111111111 f0
Envelope  d @87d1: 433322222221111111111111 f0
Envelope  e @87de: 3222222111111111111111 f0
Envelope  f @87ea: 211111111111111111 f0
Envelope 10 @87f4: 998877766655544433333332222222222111111111111111 f0
Envelope 11 @883f: 23455544333322 ff
Envelope 12 @8847: 87654321443321113221111121111111111111 ff
Envelope 13 @880d: 6555544433333333222222221111111111111111 f0
Envelope 14 @885b: 666542213221111121111111111111 ff
Envelope 15 @8822: fbbaaa99999998887777776666665554444443333322222222111111 f0
Envelope 16 @8718: 7611111431 ff
Envelope 17 @875d: 111122223333444444455555556666777888765432 ff
Envelope 18 @873c: 9876632287765311 f0
Envelope 19 @8735: 233332222222 ff
Envelope 1a @8722: 433322222222222111111111111111111111 f0
Envelope 1b @871e: 334566 ff
Envelope 1c @8773: 111122 ff
Envelope 1d @8793: c876666655555544 ff
Envelope 1e @886b: a8754321433321113221111121111111111111 ff

Code to load a volume envelope address:
8415    LDA $86DA,Y
8418    STA $B2
841A    LDA $86DB,Y
841D    STA $B3

Same set of pitch envelopes:
824B    LDA $B2
824D    CMP #$31
824F    BNE $8253
8251    LDA #$27
8253    TAY
8254    LDA $82DA,Y
8257    PHA
8258    LDA $07C3,X
825B    CMP #$46
825D    BNE $8264
825F    PLA
8260    LDA #$00
8262    BEQ $82C2
8264    PLA
8265    JMP $82C2
8268    LDA $B2
826A    TAY
826B    CMP #$10
826D    BCS $8275
826F    LDA $8311,Y
8272    JMP $82C8
8275    LDA #$F6
8277    BNE $82C8
8279    LDA $07C3,X
827C    CMP #$4C
827E    BCC $8284
8280    LDA #$FE
8282    BNE $82C8
8284    LDA #$FE
8286    BNE $82C8
...
8288    LDA $07D1,X <- starts here
828B    STA $B2
828D    LDA $B0
828F    CMP #$20
8291    BEQ $82A7
8293    CMP #$A0
8295    BEQ $82B6
8297    CMP #$60
8299    BEQ $8279
829B    CMP #$40
829D    BEQ $8268
829F    CMP #$80
82A1    BEQ $824B
82A3    CMP #$C0
82A5    BEQ $824B
82A7    LDA $B2
82A9    CMP #$0A
82AB    BNE $82AF
82AD    LDA #$00
82AF    TAY
82B0    LDA $8307,Y
82B3    JMP $82C2
82B6    LDA $B2
82B8    CMP #$2B
82BA    BNE $82BE
82BC    LDA #$21
82BE    TAY
82BF    LDA $82E6,Y
82C2    PHA
82C3    TYA
82C4    STA $07D1,X
82C7    PLA
82C8    PHA
82C9    LDA $07C8,X
82CC    BNE $82D8
82CE    PLA
82CF    CLC
82D0    ADC $B1
82D2    LDY $BE
82D4    STA Sq0Timer_4002,Y
82D7    RTS
82D8    PLA
82D9    RTS

The code that determines whether a given envelope has the triangle "forever" flag set:
8649    LDA $079C
864C    AND #$C0
864E    BNE $8653
8650    TYA
8651    BNE $865B
8653    CMP #$C0
8655    BEQ $8650
8657    LDA #$FF

1b:898f byte[$18]: Low track header offsets. All 0s.
1b:89a7 byte[$19]: High track header offsets. All 0s.
1b:89c3 struct: Single track header block for both offset tables
1b:89cd struct: Track $33 header

Track bank 0: Header offset table 898f, header block base 89c3:
Track bank 1: Header offset table 89a7, header block base 89c3:
   X Beginnings Ending @89c3:   +0  +28  8cbf  8cb1  8cd1  8cdd
    Square 1 @8cbf: 8ae3 8d2c 89ed 8b80 8bc6 8c24 8a0e 8ae3 8a9b 8dfa
    Square 2 @8cb1: 8a5c 8ceb 89d7 8b2d 8a5c 8a11 0000
    Triangle @8cd1: 8dfa 8e24 8a04 8c3a 8b28 8b28 8e48
    Noise    @8cdd: 8e48 8e4d 8a09 8c81 8e48 8e48 8e48

   33 Beginnings Staff Roll @89cd:   +0  +18  8e6b  8e79  8e87  8e9f
    Square 1 @8e6b: 8ebb 9028 937e 93b8 | 9403
    Square 2 @8e79: 8efb 90aa 913d 916b | 9445
    Triangle @8e87: 8f46 8f76 8f76 8fe8 9005 8fe8 900f 91e4 9229 | 8eaf
    Noise    @8e9f: 8f86 8faa 9279 929f 9333 | 8eb5
	
As with normal track $32, ending track $33 is not present in the header offset tables and is hard-coded in the BeginTrack function:
8349    CMP #$33
834B    BEQ $835B
...
835B    LDX #$00
835D    LDY #$00
835F    LDA $89CD,Y
8362    STA $0790,X
8365    INY
8366    INX
8367    TXA
8368    CMP #$0A
836A    BNE $835F
836C    JMP $8386

Code to load a bank 0 track header:
8373    LDA $898F,Y
8376    TAY
8377    LDX #$00
8379    LDA $89C3,Y
837C    STA $0790,X
837F    INY
8380    INX
8381    TXA
8382    CMP #$0A
8384    BNE $8379

Code to load a bank 1 track header:
8325    LDA $89A7,Y
8328    TAY
8329    LDX #$00
832B    LDA $89C3,Y
832E    STA $0790,X
8331    INY
8332    INX
8333    TXA
8334    CMP #$0A
8336    BNE $832B