Known Issues¶

Snapshot: 2026-11-01. This list covers the supported local corpus and the current prototype state. It is not a compatibility guarantee.

Release scope: v1.0.0 ships with these known issues documented; full-race completion, extra title scripts, M13.5/M13.6 visual/high-resolution review, M14 research, Pi/arm64 validation, installers, and the optional JIT are post-1.0. See ReleaseChecklist.md. As of 2026-11-02 v1.0.0 is published on GitHub: the source is tagged v1.0.0, the unified Windows/Linux/macOS x64 bundles and checksums are attached, and legal/attribution sign-off is recorded.

Compatibility sweep status¶

• The 12 titles in the matrix below are validated. The first full loadability sweep (J:\Panasonic 3DO, 589 CHDs, plus G:\MAME\MAME Software List CHDs\3do, 5 CHDs) completed on 2026-10-30 and was extended on 2026-11-01: 593 rendered, 1 known boot failure, 0 not loadable out of 594. The procedure is in CompatibilitySweep.md; the per-disc table is GameCompatibilityResults.md.
• The 2026-11-01 extended-boot retry reran all 18 non-rendered rows. The five former not-loadable rows and 12 black/blank titles now render; only Crash 'n Burn (Japan) remains. WorldCup Super Stadium renders with the FZ-10J BIOS plus its Kanji font ROM, which is now classified as BIOS2. The old triage notes are kept below.
• The five not-loadable rows were triaged on 2026-10-30:
• Mirai Shounen Conan - Digital Library reported a CHD sector-read error at LBA 1 once during the sweep. Repeated 3,000-frame runs now complete with a stable menu frame (PC 0x000284EC, hash 0xBE2A023B); treat the sweep failure as a transient disc/read error, not a reproducible emulator defect.
• The four Arcade CD-ROM titles (Crime Patrol, Mad Dog II, Orbatak, Shootout at Old Tucson RE3) stall at a starfield or the storage-manager shell with panafz1.bin, but complete 3,000 frames and render game content with panafz10-patched.bin plus the default pad. The 4DO notes about a patched BIOS match this result.
• The 12,000-frame rerun of the 13 black/blank titles shows that Ishida Yoshio Kudan no Igo Seiha, both Konpeki no Kantai discs, and all three Myst discs render by 6,000-9,000 frames. The remaining titles are BIOS-sensitive or still under investigation:
• Crash 'n Burn (Japan) renders a purple boot screen only with the Anvil BIOS and is still stuck there at 60,000 frames; panafz1, panafz10, GoldStar, and Sanyo all end in an invalid PC, and the Japanese Anvil BIOS gives a green screen. The USA/Korea and USA Not-for-Resale revisions render with panafz1, so this is a Japan-revision issue, not a general Crash 'n Burn failure.
• Powers Kingdom (Europe) renders its animated intro with the Anvil BIOS by 30,000 frames, matching the 4DO note "Use Anvil-bios to load EU version of game".
• Battle Chess (Europe) is PAL-only and refuses NTSC system software with "This is not a PAL TV system!" at PC 0x00088EDC. The European Anvil BIOS (panafz10e-anvil.bin) reaches the title screen at 6,000 frames and the board at 30,000; the USA and Japan discs boot with panafz10.
• Slayer is region-sensitive: the Europe disc renders its credits with panafz1 at 12,000 frames, while the USA disc stays black with panafz1 and needs panafz10 (also GoldStar/Sanyo) to reach its title menu at 60,000 frames.
• WorldCup Super Stadium changes from a solid blue screen to the same Anvil boot screen as Crash 'n Burn (Japan); both are still stuck at 60,000 frames, so the Anvil BIOS is not a fix for these two.
• Olympic Summer Games now proceeds past the "Insert a controller into controller port!" screen because headless run/trace attach a default player-1 pad. A/P input reaches the credits screen. This is a CLI input fix, not a disc-specific patch.
• The baseline sweep used panafz1.bin only, so its Loadable/No video and Not Loadable labels must not be treated as final. A BIOS-aware sweep with panafz10-patched and the Anvil BIOS is required before the 5DO status columns are filled.
• The 4DO wiki list is a reference, not a guarantee. Filename matching does not prove the local image is the same revision, and a 4DO score of 100 does not mean 5DO has the same behavior.
• --high-res is FreeDO-style line doubling, not true internal 640x480 rendering. The vertical detail remains 240 lines. See HighResolutionCelResearch.md. M14 is post-1.0.
• Linux x64 validation (2026-11-02): the full test suite (1,473/1,473), CLI selftest, bench, info, bios info, a 3,000-frame Wolfenstein boot, non-silent audio, and the frontend --smoke-test pass on Linux Mint 22.3 (Mesa llvmpipe). The GL probe timed out in the VM's SSH/llvmpipe session, so GPU presentation on Linux is unvalidated; the CLI/frontend ship as a preview/best-effort build. macOS validation is post-1.0. The local Linux target is the Hyper-V LinuxMint VM (D:\Hyper-V\VMs\LinuxMint).
• The project is donationware (non-commercial, source-available). Legal/attribution sign-off is recorded (2026-11-02); donations do not change the upstream non-commercial restriction.

Real-game status¶

Renderer¶

• HQx 2x/3x/4x are implemented as opt-in CPU expansions followed by sharp-bilinear finishing; GPU xBR and FSR are available in the optional Vulkan backend, while HQx remains CPU-bound. HQx 4x costs about 7.5 ms/frame on synthetic checkerboard content and about 15 ms/frame on random noise at 320x240, so it is not recommended with --high-res on slow CPUs.
• CRT bloom is implemented as a 3x3 native-resolution glow in the CRT filter.
• FSR 1.0 is opt-in (EASU + RCAS, two GPU passes). It has a sharpness setting and MIT attribution. The 4K WGL probe measures present 0.132 ms mean / 1.191 ms p99 and GPU 0.441/0.483 ms; the optional Vulkan backend measures 0.604/1.303 ms present and 0.404/0.415 ms GPU. The Vulkan figures exclude the optional per-frame readback; the desktop --gl-backend vulkan path still renders offscreen and copies the frame back.
• The xBR path now samples the GPU-expanded palette texture directly; it no longer uploads a CPU FrameAssembler copy. WGL and ANGLE 4K xBR probes pass, and the 320x240 xBR capture is within one mean channel level of the accurate frame.
• Tier A 4K presentation is measured with --gl-probe (RTX 4070: sharp-bilinear GPU p99 0.089 ms, present p99 0.208 ms, zero renderer/mailbox allocations per frame). Windows ANGLE/GLES 3.0 is validated (4K present p99 0.47 ms, pixel parity with the CPU oracle); GLES 3.1, Tier B desktop timing, and 100/150/200% DPI validation are not complete.
• The platform swap interval is wired (WGL/GLX/EGL) and reports whether the extension accepted the request. The Avalonia compositor paces the window independently, so a requested vsync may not cap presentation at 60 Hz; the probe reports the renderer cost separately.
• Display refresh above 60 Hz is re-presentation, not interpolation. The 3DO outputs 60 fields per second (50 for PAL), so DisplayRefreshRate (Settings > Video) re-presents the latest frame more often and lowers presentation latency, but motion stays at the console rate. The achieved rate is also bounded by the platform compositor (Avalonia 12 raises its render timer to the monitor frequency on Windows; other platforms may stay at 60). Frame interpolation is not implemented.
• The GPU probe's residual ~2.3 KB/frame allocation is outside OpenGlRenderer.Present and comes from the Avalonia UI/compositor loop; the renderer/mailbox path itself is zero-allocation after warm-up.
• Linux/macOS OpenGL launch validation is not complete.
• The optional Vulkan backend (--gl-backend vulkan / --vk-probe) hosts a native Win32 child window inside the Avalonia window on Windows, so the desktop path has no CPU readback. The child window is outside Avalonia's compositor, so Avalonia-drawn overlays over the video rectangle are obscured; X11/Wayland/Metal surfaces and non-Windows Vulkan device validation are pending. The offscreen/readback path remains for probes, screenshots, and non-Windows fallback. xBR-lv2 and FSR 1.0 (EASU + RCAS) are GPU passes; HQx 2x/3x/4x use the shared CPU expansion and are CPU-bound. See Vulkan.md.

Tooling and UI¶

• fs list/fs extract now parse the Opera file system directly from ISO, BIN, CUE+BIN, and CHD images. The parser handles multi-block directories and burst/gap file layouts; malformed or non-3DO images fail with a clear parse error. disc tracks reports ISO, BIN, and CUE images as a single 2048-byte user-data track.
• CLI JSON casing is split: state inspect/state slots are PascalCase for historical compatibility; other commands are camelCase.
• Save-state format version 2 compresses large sections with Brotli, so a state is typically 0.6-2.0 MB instead of the ~28 MB uncompressed size. Version-1 states still load and remain ~25 MB. The state still contains the 22 MB maximum RAM backing and the VDL frame before compression; ten compressed slots use a few MB. Older builds that only understand version 1 reject new states with Unsupported save-state version 2.
• The save-state header records the disc hash. Loading with a different disc now adds a warning to StateWarnings (surfaced by the CLI and the desktop status line) but still loads; only BIOS/emulator-version mismatches are otherwise warned about. Verify slot metadata before continuing a run.
• Some code comments are stale (for example EmulatorTuning.HighResolution says the mode is reserved even though it is implemented). Treat behavior/tests as authoritative.

Packaging and platforms¶

• CI builds three x64 bundles: Windows, Linux, and macOS. Windows and Linux run the CLI and frontend smoke tests; the macOS x64 bundle is cross-published on Linux and validated as Mach-O x86_64, but it is not executed, so macOS runtime validation is post-1.0.
• arm64 (Windows/Linux/macOS) is not hardware-validated.
• Release bundles are framework-dependent and not trimmed. The CLI and desktop app publish as single-file apphosts (PublishTrimmed=false); the .NET 10 runtime must be installed on the host and is not bundled. PDB and XML documentation files are removed from the bundles. Trimming remains available for developer and NativeAOT experiments. See packaging/README.md.
• NativeAOT, installers, signing, and notarization are not complete. The opt-in win-x64 CLI AOT build is validated, including live OpenAL; the frontend AOT build starts/renders and its bundled OpenAL path was validated with OpenAL's null device (ALSOFT_DRIVERS=null) on 2026-10-29.
• The macOS gamepad backend is not implemented.
• The bundled OpenAL Soft 1.23.1 runtime adds an LGPL-2.0-or-later binary distribution obligation to the release. The notice, complete license text, three-year written source offer, and relinking instructions ship in OpenALSoft.md and OpenAL-Soft-COPYING.txt; the project-owner legal sign-off is recorded in ReleaseLegalReview.md (2026-11-02).

Audio¶

• The DSP sample clock was corrected on 2026-10-27 to exactly 44,100 samples per emulated second. The old FreeDO 8.24 clock ran ~0.7% fast; audio content is the same, but the 3,000-frame boot keys and some FMV-timed frames changed. See TestCorpus.md 1.1/1.5a2.
• Live OpenAL output requires a playback device. If none is present the app logs a warning and runs silently; the DSP still executes. The CI/automated audio smoke test uses OpenAL's null backend (ALSOFT_DRIVERS=null).
• Road Rash's loud race mix reaches full scale (2,036 clipped frames in a 10 s 92k-state capture). WAV captures keep the raw DSP output; live OpenAL playback applies a soft peak limiter (0.8 threshold / 0.9 ceiling) so the resampler does not hard-clip. The 2026-10-28 pass fixed the remaining live-output crackle (buffer ownership), and FIVEDO_AUDIO_TAP=<prefix> records the exact queued PCM plus a per-buffer timing log for future diagnosis.
• The 90 s Road Rash capture matches Opera's spectrum and RMS envelope (spectral cosine 0.9994, 441.4 Hz tone identical). The only remaining audio check is a manual DSP mode-change listen, and no current title was observed stopping the DSP mid-run.
• Frontend NativeAOT audio is not validated; the trimmed IL and CLI AOT paths are.

Emulation¶

• CD command/status timing is approximate. The README/plan describe the remaining libopera differential work; do not port opera_cdrom.c wholesale.
• The former static READ_ID-only wait states are now addressed by a CD media-access pulse: two consecutive READ_ID polls with at least 50 frames between them set poll bit 0x40, which Portfolio uses to finish a post-race/post-load transition. This advances Road Rash's ~42k/~92k/100k screens to BUSTED, race select, and a new race. Alone's intro and Wolfenstein's fresh-game load share the old signature and should be re-checked with this fix. The current 3,000-frame audio-clock keys are in TestCorpus.md 1.1.
• High-resolution mode is opt-in and validated mainly with Lemmings. It line-doubles 240 lines to 480; it is not true vertical high-resolution rendering. A true 640x240 non-interlaced mode has not been identified. Research options are in HighResolutionCelResearch.md.
• PAL video, guest ODE prompts, CD-DA read-ahead/subcode, netplay, and additional peripherals are out of scope for v1. Multi-track TOC, raw CD-DA sectors with volume/mute, and M3U multi-disc playlists are implemented; known-title disc audio evidence remains pending.
• Portfolio OS SWI HLE (--swi-hle) is an opt-in performance mode, not a timing model. The host math matches opera_fixedpoint_math.c, but HLE skips the guest handler's cycles and register clobbers. AutoBahn Tokio and Ballz boot and run with HLE but produce different frame hashes; leave it off for compatibility or use a per-game profile. --swi-comments shows which SWIs a title calls.

Logging and bug reports¶

• Serilog writes rolling daily files under the per-user log directory and keeps seven days. The desktop Logs dock/viewer is fed by the same pipeline.
• Warning-or-higher events are submitted asynchronously to the configured bug-report API with the required environment, error, and exception details. Submission is deduplicated for five minutes, capped at ten per minute, and disabled when FIVEDO_BUG_REPORTS=0 or in CI/test runs. Expected environmental conditions such as a missing audio device are logged as warnings for the user but marked with WithoutBugReport() so they are not filed as bugs. Automated smoke and GPU-probe runs disable bug reporting entirely. If the endpoint is unreachable, the local file remains the source of truth and the submission is dropped after the HTTP timeout.
• The submit API key is embedded per the service's client instructions; override it with FIVEDO_BUGREPORT_API_KEY for a different deployment.
• Launch statistics send only the application id (5do) and version to the ApplicationStats service. No user or game data is included; set FIVEDO_STATS=0 to opt out.

Legal¶

• The project is licensed under the FreeDO modified GNU LGPL (see the root LICENSE). That license includes a prohibition on commercial use without the owners' approval. A distribution/attribution review is still pending before any public build.
• The repository does not include BIOS ROMs, game images, or extracted assets.

Memory capacity and CPU clock options¶

• Expanded DRAM/VRAM layouts (41, 42, 81, 82, E2, F1) are implemented and validated by unit tests plus a homebrew probe ROM, but retail titles are not expected to boot with them. Opera documents the memory-capacity option as homebrew-only, and the local Lemmings (USA) test stops on the boot screen with more than 2 MB of DRAM. The stock 21 layout remains the default and its golden hashes are unchanged.
• A 2 MB VRAM layout (22) keeps the stock DRAM amount and still runs, but changes the VRAM base the guest sees and therefore the rendered frame; do not use it for compatibility captures.
• The CPU clock option supports 0.5x-4x. It is a timing override, not a performance switch with a compatibility guarantee. The stock 12.5 MHz clock is unchanged and is the only validated setting for the compatibility matrix. Save states record the clock and warn on a mismatch.