Instruments
Instruments in Trackerboy consists of sequences that modulate a certain parameter once per frame. Sequences are essentially the same as what other trackers/drivers call macros.
Instruments in Trackerboy are generic, and can be used on any channel. Assigning a channel to an instrument is for organization and previewing purposes only.
Instruments in a module are stored in a table, which can have up to 64 items. The id of an instrument is its 6-bit index in this table, which is referenced in track data.
Each instrument has a sequence for the following parameters:
Example sequences will be provided throughout this page like this: [1 | 2 3].
The sequence data will be within the square brackets and a loop index (if
present) will be specified with the | character.
Arpeggio
This sequence modulates the current note. Each value in the sequence is a relative semitone offset that will change the current note being played.
Using this sequence with a loop index allows for more advanced arpeggios than the 0xy effect.
The 0xy effect is equivalent to using a sequence
of [| 0 x y] where x and y are the effect parameters.
Panning
This sequence modulates the channel's panning. It functions similarly to the I0x effect. Values in this sequence should range from 0 to 3 for mute, left, right and middle, respectively.
Example uses:
- A sequence of 1 value to just set the panning
- Setting the panning to mute at the end of the sequence for frame timed cuts
- Alternating between left and right for an echo effect
Pitch
This sequence modulates the channel's frequency. Each channel has a counter that is modified by the current instrument's pitch sequence. This counter value is added when calculating the frequency. Each value in the sequence adds to this counter.
For example consider this sequence: [1 1 -1 -1]
On frame 0, the counter is now 0 + 1 = 1 and the frequency is offset by 1
On frame 1, the counter is now 1 + 1 = 2 and the frequency is offset by 2
On frame 2, the counter is now 2 + -1 = 1 and the frequency is offset by 1
On frame 3 (and onward) the counter is now 1 + -1 = 0 and the frequency is offset by 0
If we add a loop index at 0, we have created a simple triangle vibrato effect that alternates from 0 to 2.
To have a triangle vibrato that alternates from -2 to 2 use this:
[-2 | 1 1 1 1 -1 -1 -1 -1]
To add a downward slide do this: [-2 | 1 1 1 1 -1 -1 -1 -1 -1]
Timbre
This sequence modulates the channel's timbre. Channel timbre is a channel-specific setting. For pulse channels it is duty, for the wave channel it's the volume and for the noise channel it's the step-width. Using a timbre sequence has a similar effect to using the V0x effect. Values in this sequence should range from 0 to 3.
Example uses:
- Using this sequence on a pulse channel allows you to do PWM (pulse width modulation).
- Use a 7-bit LFSR instead of the default 15-bit on the noise channel.
- Can be used for frame timed cuts on wave channel by having a 0 at the end of the sequence.
Loops
Sequences can be looped by specifying a loop index. The sequence will loop back to this index when it reaches the end.