Rearranged effects list (and recovered concepts doc).

doc/3-pattern/effects.md

@@ -1,78 +1,97 @@
 # effect list
 
-most of the effect numbers are from ProTracker/FastTracker 2.
-however, effects are continuous, which means you only need to type it once and then stop it with an effect value of `00`.
+Most of the effect numbers are from ProTracker / FastTracker 2.
 
-- **`00xy`**: arpeggio. after using this effect the channel will rapidly switch between `note`, `note+x` and `note+y`.
-- **`01xx`**: slide up.
-- **`02xx`**: slide down.
-- **`03xx`**: note portamento.
-  - a note must be present for this effect to work.
-- **`04xy`**: vibrato. `x` is the speed, while `y` is the depth.
-  - maximum vibrato depth is ±1 semitone.
-- **`07xy`**: tremolo. `x` is the speed, while `y` is the depth.
-  - maximum tremolo depth is -60 volume steps.
-- **`08xy`**: set panning. `x` is the left channel and `y` is the right one.
-  - not all chips support this effect.
-- **`80xx`**: set panning (linear). this effect behaves more like other trackers:
+However, effects are continuous, which means you only need to type it once and then stop it with an effect value of `00` or no effect value at all.
+
+## volume
+
+- `0Axy`: **Volume slide.**
+  - If `x` is 0 then this is a slide down.
+  - If `y` is 0 then this is a slide up.
+- `F8xx`: **Single tick volume slide up.**
+- `F9xx`: **Single tick volume slide down.**
+- `F3xx`: **Fine volume slide up.** 64× slower than `0Axy`.
+- `F4xx`: **Fine volume slide down.** 64x slower than `0Axy`.
+- `FAxy`: **Fast volume slide.** 4× faster than `0Axy`.
+  - If `x` is 0 then this is a slide down.
+  - If `y` is 0 then this is a slide up.
+
+- `07xy`: **Tremolo.** Changes volume to be "wavy" with a sine LFO. `x` is the speed, while `y` is the depth.
+  - Maximum tremolo depth is -60 volume steps.
+
+## pitch
+
+- `E5xx`: **Set pitch.** `00 is -1 semitone, `80` is base pitch, `FF` is nearly +1 semitone.
+- `01xx`: **Pitch slide up.**
+- `02xx`: **Pitch slide down.**
+- `F1xx`: **Single tick pitch slide up.**
+- `F2xx`: **Single tick pitch slide down.**
+
+- `03xx`: **Portamento.** Slides the current note's pitch to the specified note.
+  - A note _must_ be present for this effect to work.
+- `E1xy`: **Note slide up.** `x` is the speed, while `y` is how many semitones to slide up.
+- `E2xy`: **Note slide down.** `x` is the speed, while `y` is how many semitones to slide down.
+- `EAxx`: **Toggle legato.** While on, notes instantly change the pitch of the currrently playing sound instead of starting it over.
+- `00xy`: **Arpeggio.** After using this effect the channel will rapidly switch between semitone values of `note`, `note + x` and `note + y`.
+- `E0xx`: **Set arpeggio speed.** This sets the number of ticks between arpeggio values.
+
+- `04xy`: **Vibrato.** Changes pitch to be "wavy" with a sine LFO. `x` is the speed, while `y` is the depth.
+  - Maximum vibrato depth is ±1 semitone.
+- `E3xx`: **Set vibrato direction.** `xx` may be one of the following:
+  - `00`: Up and down.
+  - `01`: Up only.
+  - `02`: Down only.
+- `E4xx`: **Set vibrato range** in 1/16th of a semitone.
+
+## panning
+
+Not all chips support these effects.
+
+- `08xy`: **Set panning.** Changes stereo volumes independently. `x` is the left channel and `y` is the right one.
+- `88xy`: **Set rear panning.** Changes rear channel volumes independently. `x` is the rear left channel and `y` is the rear right one.
+
+- `80xx`: **Set panning (linear).** This effect behaves more like other trackers:
   - `00` is left.
   - `80` is center.
   - `FF` is right.
-  - not all chips support this effect.
-- **`81xx`**: set volume of left channel (from `00` to `FF`).
-  - not all chips support this effect.
-- **`82xx`**: set volume of right channel (from `00` to `FF`).
-  - not all chips support this effect.
-- **`09xx`**: set speed 1.
-- **`0Axy`**: volume slide.
-  - if `x` is 0 then this is a slide down.
-  - if `y` is 0 then this is a slide up.
-- **`0Bxx`**: jump to pattern.
-- **`0Cxx`**: retrigger note every `xx` ticks.
-  - this effect is not continuous.
-- **`0Dxx`**: jump to next pattern.
-- **`0Fxx`**: set speed 2.
+- `81xx`: **Set volume of left channel** (from `00` to `FF`).
+- `82xx`: **Set volume of right channel** (from `00` to `FF`).
+- `89xx`: **Set volume of rear left channel** (from `00` to `FF`).
+- `8Axx`: **Set volume of rear right channel** (from `00` to `FF`).
 
-- **`9xxx`**: set sample position to `xxx`\*0x100.
-  - not all chips support this effect.
+## time
 
-- **`Cxxx`**: change song Hz.
+- `09xx`: **Set speed/groove.** If no grooves are defined, this sets speed. If alternating speeds are active, this sets the first speed.
+- `0Fxx`: **Set speed 2.** During alternating speeds or a groove, this sets the second speed.
+
+- `Cxxx`: **Set tick rate.** Changes tick rate to `xxx` Hz (ticks per second).
   - `xxx` may be from `000` to `3ff`.
+- `F0xx`: **Set BPM.** Changes tick rate according to beats per minute.
 
-- **`E0xx`**: set arpeggio tick.
-  - this sets the number of ticks between arpeggio values.
-- **`E1xy`**: note slide up. `x` is the speed, while `y` is how many semitones to slide up.
-- **`E2xy`**: note slide down. `x` is the speed, while `y` is how many semitones to slide down.
-- **`E3xx`**: set vibrato direction. `xx` may be one of the following:
-  - `00`: up and down.
-  - `01`: up only.
-  - `02`: down only.
-- **`E4xx`**: set vibrato range in 1/16th of a semitone.
-- **`E5xx`**: set pitch. `80` is 0 cents.
-  - range is ±1 semitone.
-- **`EAxx`**: toggle legato.
-- **`EBxx`**: set sample bank.
-  - does not apply on Amiga.
-- **`ECxx`**: note off after `xx` ticks.
-- **`EDxx`**: delay note by `xx` ticks.
-- **`EExx`**: send external command.
-  - this effect is currently incomplete.
-- **`F0xx`**: change song Hz by BPM value.
-- **`F1xx`**: single tick slide up.
-- **`F2xx`**: single tick slide down.
-- **`F3xx`**: fine volume slide up (64x slower than `0Axy`).
-- **`F4xx`**: fine volume slide down (64x slower than `0Axy`).
-- **`F5xx`**: disable macro.
-  - see macro table at the end of this document for possible values.
-- **`F6xx`**: enable macro.
-- **`F8xx`**: single tick volume slide up.
-- **`F9xx`**: single tick volume slide down.
-- **`FAxy`**: fast volume slide (4x faster than `0Axy`).
-  - if `x` is 0 then this is a slide down.
-  - if `y` is 0 then this is a slide up.
-- **`FFxx`**: end of song/stop playback.
+- `0Bxx`: **Jump to order.** This can be used to loop a song.
+- `0Dxx`: **Jump to next pattern.** This can be used to shorten the current order.
+- `FFxx`: **Stop song.** Stops playback and ends the song.
 
-additionally each chip has its own effects. [click here for more details](../7-systems/README.md).
+## note
+
+- `0Cxx`: **Retrigger.** Repeats current note every `xx` ticks.
+  - This effect is not continuous; it must be entered on every row.
+- `ECxx`: **Note cut.** Ends current note after `xx` ticks. For FM instruments, it's equivalent to a "key off".
+- `EDxx`: **Note delay.** Delays note by `x` ticks.
+
+## other
+
+- `9xxx`: **Set sample position.** Jumps current sample to position `xxx \* 0x100`.
+  - Not all chips support this effect.
+- `EBxx`: **Set sample bank.**
+  - Does not apply on Amiga.
+- `EExx`: **Send external command.**
+  - This effect is currently incomplete.
+- `F5xx`: **Disable macro.** See macro table at the end of this document for possible values.
+- `F6xx`: **Enable macro.**
+
+Additionally, [each chip has its own effects](../7-systems/README.md).
 
 ## macro table
 
@@ -98,8 +117,8 @@ ID | macro
 11 | extra 6
 12 | extra 7
 13 | extra 8
----|-----------------------------
-20 | **operator 1 macros** - AM
+|   | **operator 1 macros**
+20 | AM
 21 | AR
 22 | DR
 23 | MULT
@@ -119,10 +138,9 @@ ID | macro
 31 | VIB
 32 | WS
 33 | KSR
----|-----------------------------
-40 | operator 2 macros
-60 | operator 3 macros
-80 | operator 4 macros
+40 | **operator 2 macros**
+60 | **operator 3 macros**
+80 | **operator 4 macros**
 
 the interpretation of duty, wave and extra macros depends on chip/instrument type: