5DO 1.5.0

5DO 1.5.0

Release date: 2026-11-08
Status: Accuracy and presentation update on the 1.4.0 feature release.

Highlights

• GPU HQx 2x/3x/4x. HQx is now a rule-table GPU pass in OpenGL/GLES, Direct3D 11,
  and Vulkan instead of a CPU switch expansion. The CPU HqxFilter remains the
  reference oracle and parity tests cover the shared rule table. On the RTX 4070,
  4K HQx presentation measures 0.14-0.34 ms per frame and the GPU pass
  0.09-0.17 ms, down from 6.82/10.93 ms CPU-bound.
• Video-clean differential panel. The 3DO background register is now kept as
  24-bit RGB through the CPU assembler and every GPU palette shader, and a zero VDL
  display-list word is treated as a stop that retains the previous bitmap. The
  50-title panel now matches 50/50 frame hashes at frames 60/120/300 (up from
  32/50).
• Reference field boundary and checkpoint sampling. RunFrame ends on the
  263/312-line VDL field boundary instead of a rounded ARM-cycle budget, and the
  differential harness captures Opera's ARM/CD checkpoint state in that
  checkpoint's own video callback. The residual same-frame instruction delta is
  11-20 at frame 60 and 23-2,223 at frame 120.
• CD interrupt and transfer parity. The Opera CD poll reset keeps the three
  interrupt enables and the POLRE media latch, and the XBUS CD FIQ is level-held
  each clock batch. READ_DATA now rejects invalid MSF and past-end transfers,
  aborts stale read-ahead, publishes status with the first queued sector, and
  accumulates sector deadlines like the reference. The command-50 boot handoff fell
  from +207,707 cycles / +86,511 instructions to -818 / -376.
• Better differential triage. Reports classify instruction-phase PC/CPSR
  divergences, CD command cadence, and per-command PC/instruction evidence.
  ISO staging is atomic with one transient-CHD retry, and a per-title capture
  failure is reported as an error instead of aborting a panel.
• Launch alias. The desktop shell accepts -fullscreen in addition to
  -f/--fullscreen, and the smoke-test marker records windowState=FullScreen
  when the launch mode was applied.

Changed

• VDLP save-state section is version 4 and Machine section is version 3. Both store
  the 24-bit background and convert packed 5-bit backgrounds from older states.
• --cd-commands now writes opcode cycle pc instructions; the differential
  harness understands the extended form.
• New diagnostics: --cd-register-trace and --clio-read-trace, plus the
  harness --timer-trace option.
• HQx shaders and rule tables are shared by the three GPU backends. The generated
  CPU switch files were removed; the compact rule table is checked in and
  regenerated by tools/generate_hqx_rules.py.

Validation

• Full suite 1,939/1,939 passes in Debug.
• dotnet build reports 0 warnings and 0 errors; dotnet format --verify-no-changes and jb inspectcode --severity=WARNING are clean.
• Opt-in GPU renderer tests pass for Direct3D 11 and Vulkan HQx 2x/3x/4x parity,
  and the opt-in WGL/ANGLE GL probe passes the HQx rule-texture path.
• 50-title differential panel: 50/50 frame hashes at frames 60/120/300,
  0 errors, and all first PC/CPSR divergences instruction-aligned to the
  neighboring reference field. The 5-title panel matches 5/5 frame hashes at
  300 frames; the 3,000-frame showcase keeps 4/5 (Road Rash remains divergent).
• Windows x64 remains the validated target. Linux x64 full-suite and CLI/frontend
  smoke validation pass; GPU presentation under llvmpipe/SSH remains
  preview/best-effort. macOS and arm64 bundles are cross-published and
  architecture-validated.

Requirements

• The .NET 10 Runtime installed on the host. The bundles are framework-dependent
  and do not include the runtime. Choose the x64 or arm64 bundle that matches
  your OS.
• A legally obtained 1 MB 3DO BIOS ROM (for example panafz1.bin).
• Legally obtained 3DO disc images in ISO, BIN, CUE+BIN, or CHD format.
• Optional: network access for the online cover catalog. Local covers and the core
  emulator work offline.

Download

System	Bundle
Windows x64	5do-1.5.0-win-x64.zip
Windows arm64	5do-1.5.0-win-arm64.zip
Linux x64	5do-1.5.0-linux-x64.tar.gz
Linux arm64	5do-1.5.0-linux-arm64.tar.gz
macOS x64	5do-1.5.0-osx-x64.tar.gz
macOS arm64	5do-1.5.0-osx-arm64.tar.gz

Each bundle contains the framework-dependent single-file CLI and desktop app,
README.md, LICENSE, THIRD-PARTY-NOTICES.md, whatsnew.md, and the
release/legal docs. See the release page
for SHA256SUMS.txt.

Known limits

• CD command cadence is the remaining behavioral differential on the 50-title panel;
  the 3,000-frame showcase still diverges on Road Rash.
• HQx GPU parity is pixel-identical on the tested synthetic probes; unusual drivers
  may still report shader or texture-format limitations and fall back to the
  unfiltered scale path.
• VRR depends on the GPU, driver, monitor, and desktop; 5DO only avoids the blocking
  swap interval.
• The differential panel's frame-hash matches are strong evidence, not a full
  compatibility claim for every title.