# Furnace tracker — C64 documentation (provenance)

Two files of the Furnace multi-system tracker's manual (tildearrow and contributors, GPL-2.0 repository), fetched verbatim on 2026-08-30 from `master` of https://github.com/tildearrow/furnace:

- `7-systems-c64.md` — `doc/7-systems/c64.md` (last changed in commit 6158c37aaf, 2025-03-23): the C64/SID system page (chip versions, waveform mixing, envelope reset = Furnace's hard restart, DC-offset digi channel, effect list).
- `4-instrument-c64.md` — `doc/4-instrument/c64.md` (last changed in commit 0b0e6d5e13, 2024-09-14): the C64 instrument editor (waveform, ADSR, duty, ring/sync, filter, macros).

Rendered versions: https://tildearrow.org/furnace/doc/latest/7-systems/c64.html and `.../4-instrument/c64.html`. Furnace is not one of the wiki's focus tools; the docs were kept as a second, independent description of SID behaviour.