additive mode for current 2-op fm synth done in v0.4
4-op fm synth with all 12 algorithms I've found. If algorithm is from OPL3 or Sega chip special tip emerges. Each op has its own macro, filter, envelope, etc. Filter of the main instrument filters overall output of the 4-op stack AFTER individual ops' filters. sort of done in v0.10.0-alpha1 (with 13 algorithms!)
commands for setting start and end points of the sample from instrument macro (the result is you can use less samples, e.g. use sine and make lower half sine and upper half sine from the same sample for different instruments) done in v0.9
Song info or song comment (separate window with arbitrary amount of text as in e.g. Impulse tracker) done in 0.10.0-alpha3
Oscilloscope in instrument editing window which shows current waveform produced by instrument done in v0.8
Exponential wave in wavegen (mainly for OPL3) done in v0.3
DPCMator in wavegen (convert any sample into DPCM NES format (only 1 step up or down for each step, 6-bit resolution) and save as 8-bit PCM sample)
Killing duplicate samples and relinking instruments to remaining 1 sample (useful for imported xms and its, combined with klystrack's sample compression it would give huge (or not) size reduction) done in v0.5
saving wavegen settings as sort of "synth patches" done in v0.3
moving klystrack config file from C:/Users/%USERNAME% to app folder which would make app portable done in v0.4
16-bit rate setting instead of current 8-bit for crazy rate songs (400 Hz, 800 Hz and so on). If rate is lower or equal to 255, save as 8-bit value (song would be 1 byte smaller!!!) done in v0.8
Full range speed setting (not 0-F as now, but 0-FF, it’s anyway saved as 8-bit value). Commands for setting each speed in 00-FF range. Helps in case of crazy rates. done in v0.8
More command columns (up to 8, absolutely not related to Furnace) done in v0.8
.vgm file export (oh god it will be crazy). Before export unnecessary complex algorithm checks where user fucked up (used FM instrument or sawtooth wave in case of exporting for 2A03, used anything except noise of 10th channel for Genesis etc.) and tells where exactly.
.sid export, possibly steal algorithm from goattracker or smth. 1-8 SIDs, user would specify each SID address (e.g. $6A0F). Sample support (4-bit and 8-bit).
FamiTracker files import (.ftm, .0cc, .dnm, .eft and others, one song at a time) kinda done in 0.10.0-alpha3
.dmf import (probably steal algorithm from… you know)
.a2m (Adlib Tracker II) file import
.rmt (Raster Music Tracker) file import
.s3m (Scream Tracker III) file import
.it (Impulse Tracker) file import
.MED (OctaMED tracker) file import
.mid/.midi file import along with some kind of klystrack own file for creating instrument banks
MIDI input support lol it sort of was there from the very first fork release, but it was proven to work in 0.10.0-alpha2
.mptm import (OpenMPT file, basically IT extenstion with lots of hacks and very poor documentation (cringe))
.fur import. I love how this tracker also uses 16-bit commands (and will probably steal some algorithms from it). Deflemask killer.
maybe some other formats import because it is fun to code the import thing
Custom envelope for instruments and thus more precise .xm (and maybe other formats) import. Maybe make Yamaha FM chips (YM2612 envelope, TL-AR-D1R-TL1-D2R-RR style) envelope as separate option. done in 0.10.0-alpha3