ReaperOfVeriod
1d6cddf3bb
Range measured: level 0 post-shrub, 16047040..16737344, 690304 bytes. Method: scan for a 16-byte header ending 0xff, then 10 zero bytes, then a run of u32 whose top nibble is 0xF. Result: 28 chunk headers on level 0, present on all 27 levels. Each chunk is +0x00 16 bytes, last byte 0xff (opaque, differs per chunk) +0x10 10 zero bytes +0x1a N tagged offsets, top nibble 0xF Within a chunk the offsets step by a chunk-specific stride. On level 0: 148, 340, 368, 288, 320, 236, 272, 384, 116, 160, 250, 580, 576. Near-constant within a chunk, different between chunks. This resolves two earlier results, both of which were half-right. The 368-byte period is one chunk's stride, not a region property. That is why the region-wide autocorrelation is flat: ~15 strides averaging to noise. The 15360-byte window where 368 scored +0.315 is the third chunk at region+30066, whose stride is 368. The "ten-entry table" earlier disconfirmed is real. Chunks carry 5 to 30 tagged offsets, 10 most common on level 0. It was disconfirmed because I tested for a fixed 148 stride across a whole region; the table exists, but 148 is one chunk's stride among many. Both errors were the same one: reporting a local measurement as a regional property. Twice now. The control methodology caught neither, because a matched control bounds significance but says nothing about scope. Not decoded: the 16-byte header, the 0xF tag, where chunk data lives, and what any chunk means. Framing established, contents not.
Going Commando
A native PC reimplementation of Ratchet & Clank: Going Commando (PlayStation 2, 2003), written in Rust.
The game is reimplemented, not emulated. There is no MIPS interpreter here and no CPU emulator: the systems are ported to Rust so they run as ordinary native code.
Status: initial scaffold. The disc is identified and verified, the
workspace builds, and nothing else is implemented yet. See
docs/roadmap.md for where things stand and what comes next.
The target
| Game | Ratchet & Clank: Going Commando |
| Platform | PlayStation 2 |
| Disc | SCUS_972.68 v1.01, USA Black Label |
| Video | NTSC, 60 Hz |
| Boot ELF SHA-1 | bacda860cbd6723142e86db56f197e47e728970f |
Verified against a real disc — see docs/disc-identification.md.
This is the build the reference projects pin; Greatest Hits v2.00 is a
different binary and is not the target.
No game content
This repository contains no game assets, no disc images, no BIOS dumps and no proprietary toolchains. You supply your own legally obtained copy of the disc as an input, the way the upstream reference projects do.
A pre-commit hook enforces this, blocking disc images, asset directories, container signatures and files over 50 MiB. If you clone elsewhere, enable it:
git config core.hooksPath .githooks
Layout
crates/
gc-formats/ asset format parsers (pure, no I/O beyond the caller's buffer)
gc-extract/ disc pipeline: identify, unpack, verify
gc-game/ game logic: hero, weapons, moby classes, progression, saves
gc-video/ IPU / MPEG-2 decode
gc-engine/ Bevy app: Graphics Synthesizer, VU0/VU1, renderer, frame loop
docs/
disc-identification.md which disc we build against, verified
roadmap.md phases, gates, current status
plan/ one file per subsystem, written as work proceeds
formats/ format specs, written as formats are reversed
tools/
identify-disc.py identify any Going Commando disc image
vendor/
rerac/ pinned upstream reference checkout (not tracked)
Building
Requires a Rust toolchain via rustup.
cargo check --workspace
cargo test --workspace
The host audio backend is disabled in Cargo.toml (see the comment there) so
that the workspace builds without system ALSA development headers. Audio decode
is the last phase of the port and lives in gc-video; re-enable it and install
alsa-lib-devel when that work starts.
Identifying a disc
python3 tools/identify-disc.py <your-disc.iso>
Reports the serial, version and video mode from SYSTEM.CNF, hashes the boot
executable, and warns when the disc is not the supported build. Reads only a
few megabytes, so it is near-instant.
How it will be verified
Visual and behavioural comparison against PCSX2, replaying recorded input and
comparing frames, level by level. The PS2 float model is reproduced rather than
approximated — see AGENTS.md.
Credits and licensing
This project learns from and is built on the work of others. Licences are
recorded in PROVENANCE.md and notices must travel with any
code derived from them.
- ReRAC — a native Rust/Bevy port of Ratchet & Clank (2002), the first game. ISC. The architecture this project follows.
- OpenRAC / rac2-gc-decomp — matching decompilation research for this game. MIT. Source of verified struct layouts and engine documentation.
- Wrench — community documentation of Insomniac's container formats. GPL, used as a specification reference only; no code is copied.
Ratchet & Clank is a trademark of Sony Interactive Entertainment. This is an unofficial fan project, not affiliated with or endorsed by Sony Interactive Entertainment or Insomniac Games.