Music Engine Description - Revision history

Bentglasstube: /* Duration LUT */

2023-08-19T05:08:49Z

Duration LUT

Bentglasstube: /* Title Music Engine */

2023-08-18T04:06:16Z

Title Music Engine

Bentglasstube: /* Title Music Engine */

2023-08-18T03:29:08Z

Title Music Engine

Bentglasstube: /* Title Music Engine */

2023-08-16T22:10:49Z

Title Music Engine

Bentglasstube: /* Title Music Engine */

2023-08-16T22:08:17Z

Title Music Engine

Bentglasstube: /* Title Music Engine */

2023-08-15T04:08:17Z

Title Music Engine

Bentglasstube: /* Title Music Engine */

2023-08-15T04:05:21Z

Title Music Engine

Bentglasstube: /* Pitch LUT */

2023-08-13T04:59:43Z

Pitch LUT

Bentglasstube: /* Title Music Engine */

2023-08-13T04:59:15Z

Title Music Engine

Bentglasstube: /* Title Music Engine */

2023-08-13T04:56:44Z

Title Music Engine

@@ Line 154: / Line 154: @@
 |'''00'''||04||0C||08||10||18||20||05||06
 |-
-|'''08'''||04||0F||09||12||1B||24||06||06
+|'''08'''||''04''||''0F''||09||12||1B||24||06||06
 |-
 |'''10'''||05||0F||0A||14||1E||28||07||06
@@ Line 162: / Line 162: @@
 |'''20'''||07||15||0E||1C||2A||38||13||12
 |-
-|'''28'''||07||15||0E||1C||2A||38||XX||XX
+|'''28'''||07||15||0E||1C||2A||38||09||0A
 |}
-The last two values in each row seem a bit strange, as they are not nice
+The base value of each row is the third one, which represents an eighth note.  The other values are usually related numbers to give these normal note lengths:
-multiples of the first entry which is usually thought of as the length of an
-eighth note.  They are usually used to make triplets which don't divide evenly by slightly shortening or lengthening the third triplet.  The last row doesn't include these two values because they are nonsensical and actually belong to the next LUT anyway.  That row is used for the credits music which presumably avoids those last two values.
+# Sixteenth note&dagger;
 ==== Pitch LUT ====

@@ Line 93: / Line 93: @@
 Rest
 C5
-Eighth note
+Eighth notes
 B4
 Quarter notes
@@ Line 113: / Line 113: @@
 Half notes
 E B3
-Quarter notes
+Eighth notes
 Rest
 End of Data

@@ Line 54: / Line 54: @@
 The pitch values are stored in a lookup table at bank 6 from <code>$808F</code> to <code>$810E</code>.  Any value from <code>$00</code> to <code>$7F</code> represents an entry in this table.
-<code>$42</code> is A4 and every semitone away from that adds or subtracts 2 from
+<code>$46</code> is A4 and every semitone away from that adds or subtracts 2 from
-the value.  Thus, C5 (three semitones above A4) is <code>$48</code>.  As in the game music engine, the value
+the value.  Thus, C5 (three semitones above A4) is <code>$4C</code>.  As in the game music engine, the value
-<code>$02</code> represents a rest.  Unlike the game music engine, <code>$00</code> also represents a rest.
+<code>$02</code> represents a rest.  Unlike the game music engine, <code>$00</code> also represents a rest but the code has special handling for <code>$02</code> so using that is recommended.
-        -2-  -3-  -4-  -5-  -6-  -7-
+       -2-  -3-  -4-  -5-  -6-  -7-
-   C  :      $18  $30  $48  $60  $78
+  C  : $04  $1C  $34  $4C  $64  $7C
-   C# :      $1A  $32  $4A  $62  $7A
+  C# : $06  $1E  $36  $4E  $66  $7F
-   D  : $04  $1C  $34  $4C  $64
+  D  : $08  $20  $38  $50  $68
-   Eb : $06  $1E  $36  $4E  $66
+  Eb : $0A  $22  $3A  $52  $6A
-   E  : $08  $20  $38  $50  $68
+  E  : $0C  $24  $3C  $54  $6C
-   F  : $0A  $22  $3A  $52  $6A
+  F  : $0E  $26  $3E  $56  $6E
-   F# : $0C  $24  $3C  $54  $6C
+  F# : $10  $28  $40  $58  $70
-   G  : $0E  $26  $3E  $56  $6E
+  G  : $12  $2A  $42  $5A  $72
-   G# : $10  $28  $40  $58  $70
+  G# : $14  $2C  $44  $5C  $74
-   A  : $12  $2A  $42  $5A  $72
+  A  : $16  $2E  $46  $5E  $76
-   Bb : $14  $2C  $44  $5C  $74
+  Bb : $18  $30  $48  $60  $78
-   B  : $16  $2E  $46  $5E  $76
+  B  : $1A  $32  $4A  $62  $7A

@@ Line 53: / Line 53: @@
 * <code>$8A</code> - 80 ticks  (half note + eighth note)
-The pitch values are stored in a lookup table at bank 6 from <code>$808F</code> to <code>$810F</code>.  Any value from <code>$00</code> to <code>$7F</code> represents an entry in this table.
+The pitch values are stored in a lookup table at bank 6 from <code>$808F</code> to <code>$810E</code>.  Any value from <code>$00</code> to <code>$7F</code> represents an entry in this table.
 <code>$42</code> is A4 and every semitone away from that adds or subtracts 2 from
 the value.  Thus, C5 (three semitones above A4) is <code>$48</code>.  As in the game music engine, the value

@@ Line 38: / Line 38: @@
 sets the duration of all future notes.  Anything else is a pitch value
 which indicates a note of the current duration should be played.  The
-low nibble of duration values keys into a lookup table at bank 6 <code>$8084</code>
+low nybble of duration values keys into a lookup table at bank 6 <code>$8084</code>
-and store the duration byte at <code>$07FF</code>.  Value durations are as follows:
+and store the duration byte at <code>$07FF</code>.  Values are as follows:
 * <code>$80</code> - 8 ticks   (sixteenth note)
@@ Line 52: / Line 52: @@
 * <code>$89</code> - 10 ticks  (eighth note triplet, third)
 * <code>$8A</code> - 80 ticks  (half note + eighth note)
-Note: <code>$8C</code>, <code>$8D</code> and <code>$8E</code> are duplicates, so these could be used for
+The pitch values are stored in a lookup table at bank 6 from <code>$808F</code> to <code>$810F</code>.  Any value from <code>$00</code> to <code>$7F</code> represents an entry in this table.
 <code>$42</code> is A4 and every semitone away from that adds or subtracts 2 from
 the value.  Thus, C5 (three semitones above A4) is <code>$48</code>.  As in the game music engine, the value
-<code>$02</code> represents a rest.
+<code>$02</code> represents a rest.  Unlike the game music engine, <code>$00</code> also represents a rest.
          -2-  -3-  -4-  -5-  -6-  -7-

@@ Line 212: / Line 212: @@
 the song data.  However, the sound effects routines make use of these
 extra notes.  For example, the sword beam effect alternates between
-playing C7 and F6.  The title music engine also has a different format which allows use of more of these notes.
+playing C7 and F6.
 ==== Noise Samples ====

@@ Line 22: / Line 22: @@
 The following songs exist in the title song table:
-. Intro
+# Intro
-. Start
+# Start
-. Build up
+# Build up
-. Main
+# Main
-. Breakdown
+# Breakdown
 The start of song 2 triggers the title to scroll into view.  The start
@@ Line 41: / Line 41: @@
 and store the duration byte at <code>$07FF</code>.  Value durations are as follows:
-  * <code>$80</code> - 8 ticks   (sixteenth note)
+* <code>$80</code> - 8 ticks   (sixteenth note)
-  * <code>$81</code> - 24 ticks  (dotted eighth note)
+* <code>$81</code> - 24 ticks  (dotted eighth note)
-  * <code>$82</code> - 16 ticks  (eighth note)
+* <code>$82</code> - 16 ticks  (eighth note)
-  * <code>$83</code> - 32 ticks  (quarter note)
+* <code>$83</code> - 32 ticks  (quarter note)
-  * <code>$84</code> - 48 ticks  (dotted quarter note)
+* <code>$84</code> - 48 ticks  (dotted quarter note)
-  * <code>$85</code> - 64 ticks  (half note)
+* <code>$85</code> - 64 ticks  (half note)
-  * <code>$86</code> - 96 ticks  (dotted half note)
+* <code>$86</code> - 96 ticks  (dotted half note)
-  * <code>$87</code> - 128 ticks (whole note)
+* <code>$87</code> - 128 ticks (whole note)
-  * <code>$88</code> - 11 ticks  (eighth note triplet, first two)
+* <code>$88</code> - 11 ticks  (eighth note triplet, first two)
-  * <code>$89</code> - 10 ticks  (eighth note triplet, third)
+* <code>$89</code> - 10 ticks  (eighth note triplet, third)
-  * <code>$8A</code> - 80 ticks  (half note + eighth note)
+* <code>$8A</code> - 80 ticks  (half note + eighth note)
-  * <code>$8B</code> - 256 ticks (two whole notes)
+* <code>$8B</code> - 256 ticks (two whole notes)
-  * <code>$8F</code> - 6 ticks   (dotted 32nd note)
+* <code>$8F</code> - 6 ticks   (dotted 32nd note)
 Note: <code>$8C</code>, <code>$8D</code> and <code>$8E</code> are duplicates, so these could be used for

@@ Line 9: / Line 9: @@
 == Title Music Engine ==
 The title music engine is different from the engine that plays music
 during the rest of the game.  In particular, it has a wider range of
 notes that can be represented.  If you want to look into the actual
-code, the title screen music engine main loop is at `$8000` (vesus
+code, the title screen music engine main loop is at <code>$8000</code> (vesus
-`$9000` for the game music loop).
+<code>$9000</code> for the game music loop).
 The metadata for the songs is all the same as in the other areas,
@@ Line 39: / Line 35: @@
 the duration and pitch together in a single byte, the title music has
 "pitch" bytes and "duration" bytes.  Any byte with the highest bit set
-(i.e. anything >= `$80`) is interpreted as a duration change, which
+(i.e. anything >= <code>$80</code>) is interpreted as a duration change, which
 sets the duration of all future notes.  Anything else is a pitch value
 which indicates a note of the current duration should be played.  The
-low nibble of duration values keys into a lookup table at bank 6 `$8084`
+low nibble of duration values keys into a lookup table at bank 6 <code>$8084</code>
-and store the duration byte at $07FF.  Value durations are as follows:
+and store the duration byte at <code>$07FF</code>.  Value durations are as follows:
-   * `$80` - 8 ticks   (sixteenth note)
+   * <code>$80</code> - 8 ticks   (sixteenth note)
-   * `$81` - 24 ticks  (dotted eighth note)
+   * <code>$81</code> - 24 ticks  (dotted eighth note)
-   * `$82` - 16 ticks  (eighth note)
+   * <code>$82</code> - 16 ticks  (eighth note)
-   * `$83` - 32 ticks  (quarter note)
+   * <code>$83</code> - 32 ticks  (quarter note)
-   * `$84` - 48 ticks  (dotted quarter note)
+   * <code>$84</code> - 48 ticks  (dotted quarter note)
-   * `$85` - 64 ticks  (half note)
+   * <code>$85</code> - 64 ticks  (half note)
-   * `$86` - 96 ticks  (dotted half note)
+   * <code>$86</code> - 96 ticks  (dotted half note)
-   * `$87` - 128 ticks (whole note)
+   * <code>$87</code> - 128 ticks (whole note)
-   * `$88` - 11 ticks  (eighth note triplet, first two)
+   * <code>$88</code> - 11 ticks  (eighth note triplet, first two)
-   * `$89` - 10 ticks  (eighth note triplet, third)
+   * <code>$89</code> - 10 ticks  (eighth note triplet, third)
-   * `$8A` - 80 ticks  (half note + eighth note)
+   * <code>$8A</code> - 80 ticks  (half note + eighth note)
-   * `$8B` - 256 ticks (two whole notes)
+   * <code>$8B</code> - 256 ticks (two whole notes)
-   * `$8F` - 6 ticks   (dotted 32nd note)
+   * <code>$8F</code> - 6 ticks   (dotted 32nd note)
-Note: $8C, $8D and $8E are duplicates, so these could be used for
+Note: <code>$8C</code>, <code>$8D</code> and <code>$8E</code> are duplicates, so these could be used for
 custom durations if desired.
 The pitch values are much more straightforward.  As far as I can tell,
-`$4C` is A4 and every semitone away from that adds or subtracts 2 from
+<code>$4C</code> is A4 and every semitone away from that adds or subtracts 2 from
-the value.  Thus, C5 (three semitones above A4) is `$52`.  The value
+the value.  Thus, C5 (three semitones above A4) is <code>$52</code>.  As in the game music engine, the value
-`$02` represents a rest.
+<code>$02</code> represents a rest.
          -2-  -3-  -4-  -5-  -6-  -7-
@@ Line 82: / Line 78: @@
 By way of an example, let's look at the main section of the vanilla
-title music.  The title metadata starts at bank 6 `$84DA`:
+title music.  The title metadata starts at bank 6 <code>$84DA</code>:
 11 14 16 19 1E 1E 1E
               ^ Main section
-The main section is the fourth song, starting at `$84DA + $16 = $84F0`:
+The main section is the fourth song, starting at <code>$84DA + $16 = $84F0</code>:
 F 3F 00
 This means there is a single phrase for the main section, which is
-repeated twice.  The phrase data is at `$84DA + $3F = $8519`.
+repeated twice.  The phrase data is at <code>$84DA + $3F = $8519</code>.
 3D 86 3A 1A 5F
-From this, we see the melody note data is located at `$863D`:
+From this, we see the melody note data is located at <code>$863D</code>:
 Quarter notes