RustyNES v3.2.0 — "Confluence" (every v3.2.0 branch in both repositories brought into one release: 17 mapper families, the VRC4 IRQ fix, an AI remediation branch audited change by change, netplay protocol 8, slim libretro states, and sixteen more boards on the MiSTer core)

RustyNES v3.2.0 — "Confluence"

Every v3.2.0 branch, both repositories, brought into one release. It adds 17 mapper families (191 to 208), among them the Bandai Datach with its barcode reader, and five more families are Curated on local-dump evidence. Five emulation defects are fixed: the VRC4's IRQ mode was read inverted, VRC2 mirroring had settings the chip does not have, Fire Hawk lost its single-screen mirroring on an iNES 1.0 header, mapper 290 did not boot, and a 24C02 EEPROM lost its word address across a START. An AI-made remediation branch was audited change by change before anything was kept: its byte-identical speed-ups are kept, and measured against the tree it joined: the APU mixes 2-6% faster and an MMC3 read about 9% faster, while its larger claims did not hold and two cartridge reads got slower for a reason not yet found; a 47% audio slowdown it introduced was found and removed; four of the five features it broke are fixed and kept, and Android audio is back on its blocking write, with the non-blocking version a ticket. Netplay moves to protocol 8, libretro save states shrink from 260 KB to about 16 KB, and new save files are owner-only. The MiSTer core gains sixteen boards, the Four Score, the Arkanoid controller, Game Genie cheats, more than eight sprites per line and custom palettes. Movies and netplay from v3.1.x are refused, and so are v3.1.x save states of Bandai FCG games.

Breaking changes

• Movies and netplay from v3.1.x are refused: EMULATION_EPOCH rises from 3 to 4, because the mapper 290, 24C02, VRC4 IRQ, VRC2 and Fire Hawk fixes change what the bus sees. Save states are not affected by the epoch.
• v3.1.x save states of Bandai FCG games are refused (mappers 16, 153, 157 and 159): their state now carries each serial EEPROM's protocol position, so a state taken mid-transaction resumes it instead of leaving the chip idle, which could make rewind, run-ahead and netplay rollback diverge. Other boards' states are unchanged.
• Netplay protocol 8 ("RNE8"): lost inputs are resent as one datagram per run of frames. A v3.1.x peer is refused as another emulator version.
• The Mapper trait requires ppu_peek (a side-effect-free PPU read for the debugger), so a mapper implemented outside this repository must add it. cpu_peek, may_unmap_prg_rom, is_save_data_dirty, clear_save_data_dirty and three barcode-reader methods are added with defaults.

Fixed

• The VRC4's IRQ runs in the mode the game asks for (mappers 21, 23 and 25): bit 2 of the IRQ control register was read inverted, so a raster split got a counter about 114 times too fast.
• VRC2 mirroring has two settings, not four, and mappers 23 and 25 with NES 2.0 submapper 3 are built as the VRC2.
• Fire Hawk gets its single-screen mirroring from an iNES 1.0 header (mapper 71, submapper 0, at the first $9000 write).
• Mapper 290 (Asder 20-in-1) boots, and a 24C02 EEPROM keeps its word address across a START (mappers 16 and 157).
• FDS disk games keep their saves on Android and iOS, and the Android screen stays on during play.

Added

• Mapper 157, the Bandai Datach Joint ROM System, with a barcode reader for the games that read cards.
• 16 more families: the MMC3-derived 114, 116, 165, 182, 197 and 215; FFE 6, 8 and 17; Tengen 158; TXC 172 and 173; Taito 207; the 235 multicarts and Waixing 252 (all Curated), and the 230 multicart (BestEffort). Mappers 47, 121, 154, 191 and 243 move to Curated. The split is now 51 Core, 130 Curated and 27 BestEffort: 181 of 208 families are accuracy-gated.
• Famicom-only carts boot as a Famicom in the coverage sweep, so ten dumps listed as blank now draw.

Changed

• Libretro save states are about 16 KB instead of 260 KB: the framebuffer is no longer stored, and a full-size state still loads.
• New save files are owner-only on Linux and macOS (0o600).
• rustls 0.23.46, for four TLS advisories published during the release (RUSTSEC-2026-0346 to 0349), in the netplay WebSocket and HTTP clients.
• The APU mixes 2-6% faster with expansion audio and 2-3% faster without, byte-identical, in two independent A/B runs.
• An MMC3 cartridge read is about 9% faster, and run-ahead on an MMC3 game about 5%, from cached bank offsets; byte-identical, two independent runs. Whole-frame time and the PPU do not change measurably. MMC5 and Sunsoft FME-7 reads measure 4.7% and 6% slower although neither read function changed; the cause is not established (docs/performance.md, "v3.2.0 import").

The AI remediation branch, audited

An unpushed agent branch arrived with 61 audit findings already applied. Nothing was merged as is. Every change was read against the code it replaced, and each defect found has a test that fails without the fix. Kept: 20 as written, 14 corrected. Reverted: 4, the audio ring write behind the 47% slowdown, an MMC5 IRQ change under which the IRQ stopped firing in real play, and two unmeasured libretro rewrites; an FDS audio formula change inside a kept finding was reverted too, because it moved every FDS game's audio. Rejected: 10, including six of its seven FPGA findings, which did not hold when re-derived in simulation and synthesis. The ledger is docs/audits/v3.2.0-round2-audit-disposition.md; the report's "certified" and "100% bit-accurate" claims are recorded as unverified, and two of them were tested and are false.

The MiSTer core

• Release candidate, not hardware-verified. No hardware has run either bitstream.
• Sixteen more boards: UN1ROM, Nichibutsu UNROM, CPROM, J87, CNROM 185, GxROM, Jaleco JF-11/14, Color Dreams, NINA-03/06, Camerica 71 (including Fire Hawk) and 232, mapper 34, Namco 108, TxSROM, TQROM and MMC1 SUROM (off-die). Each is gated against the emulator, and thirteen against a commercial game's frame (SUROM's off-die only).
• The Four Score, the Arkanoid controller and Game Genie cheats, gated against goldens exported with the same device.
• More than eight sprites per line (on-die build) and custom .pal palettes with the emulator's emphasis model.
• The oracle pin moves to v3.2.0 (the merge, 40d4bf1c): all 848 golden artifacts from 189 stems reproduce byte for byte.
• The co-simulation ladder: 259 passed, 0 failed, 3 expected failures on-die and 260 / 0 / 5 off-die (v3.1.0: 212 / 0 / 1 and 213 / 0 / 1), each one run of a frozen tree, nothing skipped. The new expected failures are named and graded both ways: two commercial frames still differ from the emulator's, by one pixel (a sprite at X=255 on its last row) and by three scanlines of a mid-frame raster change, neither yet attributed; off-die, two more are a CHR-RAM read-back defect that predates this release (T-MISTER-OFFDIE-CHRRAM).
• New bitstreams at fitter seed 4, chosen from eight seeds swept on build date 261014 by the rule both builds share: the on-die build's binding margin chooses, and the off-die build must close at the chosen seed. Seeds 5 and 6 lead on-die but do not close off-die; seeds 1 (v3.1.0's) and 4 tie next, and only 4 closes off-die. Each was compiled twice to the same bytes:
  • on-die RustyNES_MiSTer-v3.2.0.rbf, md5 e24820de2e302d3f6912524b3c97a2be (+0.213 ns setup, +0.079 ns hold);
  • off-die RustyNES_MiSTer-v3.2.0-offdie.rbf, md5 c33ae2b14e5b8e07a68b4335c728ca03 (+0.038 / +0.080 ns). The +0.038 ns path is inside the FPGA (the SDRAM controller's read data into the CPU), so board delay does not consume it; the SDRAM read capture itself has +0.453 ns setup and +1.180 ns hold over all four timing corners, assuming zero board delay.

Verification

• --features test-roms,commercial-roms: 3,669 passed, 0 failed, 16 ignored, across 176 test binaries.
• The local commercial suites: external_real_games 60/0, external_extended 169/0, external_coverage 6/0 over every staged dump, 25 of them baselined new in this release.
• Every clippy, rustdoc, no_std and wasm invocation CI runs (23), clean.
• AccuracyCoin 146/146, nestest 0-diff, the epoch fingerprint at epoch 4, now recorded as the released epoch.

Install

• Download the pre-built binaries for Linux, macOS, and Windows below.
• The MiSTer core bitstreams are attached below, as a release candidate, not hardware-verified. The on-die build is RustyNES_MiSTer-v3.2.0.rbf, also attached under its datecoded name, and the off-die build is RustyNES_MiSTer-v3.2.0-offdie.rbf.
• The WebAssembly build is live at doublegate.github.io/RustyNES.
• The RetroArch core is in RetroArch's Online Updater on the platforms the libretro buildbot publishes to.
• Licensed under GPL-3.0-or-later.