Drum machine one-shot samples (TR-707 / TR-808 / TR-909)
Hosted under: public/audio/drum-machine/{tr-707,tr-808,tr-909}/
Used in: 鼓机编曲台（/arranger）、和弦进行 Demo 鼓组等

Upstream packaging: https://github.com/fluid-music/open-drums
Original archives: http://machines.hyperreal.org/ (Roland TR machine sample sets)

Each kit uses 8 tracks: kick, snare, hihat_closed, hihat_open, crash, ride, tom1, tom2, tom3
Track ids: src/features/drum-core/data/tracks.ts
Kit registry: src/features/drum-core/data/kits.ts

--- TR-707 (tr-707/) ---
Source pack: TR707WAV (fluid-music/open-drums/tr-707)
License: README in pack states "public domain, so use em however ya want"
File mapping (renamed on import):
  kick.wav          <- BassDrum1.wav
  snare.wav         <- Snare1.wav
  hihat_closed.wav  <- HhC.wav
  hihat_open.wav    <- HhO.wav
  crash.wav         <- Crash.wav
  ride.wav          <- Ride.wav
  tom1.wav          <- HiTom.wav
  tom2.wav          <- MedTom.wav
  tom3.wav          <- LowTom.wav

--- TR-808 (tr-808/) ---
Source pack: Michael Fischer TR-808 Sound Sample Set 1.0.0 (1994)
Packaged as TR808WAV in fluid-music/open-drums/tr-808
Also mirrored: https://github.com/tidalcycles/sounds-tr808-fischer (CC0 1.0)
Original author terms: "ABSOLUTELY FREE" (see TR808.TXT in upstream pack)
File mapping:
  kick.wav          <- BD0050.WAV
  snare.wav         <- SD2510.WAV
  hihat_closed.wav  <- CH.WAV
  hihat_open.wav    <- OH50.WAV
  crash.wav         <- CY0050.WAV
  ride.wav          <- CY0075.WAV
  tom1.wav          <- LT50.WAV
  tom2.wav          <- MT50.WAV
  tom3.wav          <- HT50.WAV

--- TR-909 (tr-909/) ---
Source pack: Jason Baker / Rob Roy Recordings TR-909 set (1995)
Packaged as TR909all in fluid-music/open-drums/tr-909
Upstream readme: free to copy/distribute; do not modify samples; not for profit redistribution
Full text: TR909all/TR909SET.TXT in open-drums repo
File mapping:
  kick.wav          <- BT3A0D0.WAV
  snare.wav         <- ST0T0S3.WAV
  hihat_closed.wav  <- HHCD4.WAV
  hihat_open.wav    <- HHOD4.WAV
  crash.wav         <- CSHD4.WAV
  ride.wav          <- RIDED4.WAV
  tom1.wav          <- HT3D0.WAV
  tom2.wav          <- MT3D0.WAV
  tom3.wav          <- LT3D0.WAV

Note: Roland TR-707, TR-808 and TR-909 are trademarks of Roland Corporation.
These files are community-recorded one-shots, not official Roland sample libraries.