Release 1.4.0

5DO 1.4.0

Released: 2026-11-07

5DO 1.4.0 is a feature and accuracy update on the 1.3.0 field-handling release. It adds online cover art, latency controls, unsigned-disc support, and the exact 59.94 Hz NTSC clock used by the reference core.

Highlights

• Online cover art. An optional content-addressed WebP catalog at https://assets.purelogiccode.com/5do/v1 provides 473 unique covers and maps 645 of 653 4DO game IDs. 5DO downloads only the covers it needs, verifies every image by SHA-256, and supports an optional ~27 MB bulk pack for offline use. Settings > Covers and covers update/download/match/verify/cache expose the feature.
• Latency controls. Settings > Video adds 0-2 frame run-ahead, a 0-8 frame presentation delay, and VRR/adaptive-sync presentation. Settings > Audio and --audio-sync -250..250 add a host A/V offset. Run-ahead uses a reusable uncompressed machine snapshot and auto-disables after repeated frame-budget overruns.
• Unsigned discs. Settings > Paths and --allow-unsigned-discs disable the BIOS media RSA check in memory. A known No-RSA BIOS is preferred; otherwise a compatible retail 1 MB image is patched with the documented two-site bypass. The BIOS file is never modified.
• Exact NTSC clock. NTSC now runs at 60000/1001 (59.94 Hz, 208,541 cycles per field at 12.5 MHz) instead of 60.00 Hz. The rational VDL accumulator removes the per-batch 8.24 rounding that ran the scanline clock about 0.09% fast.
• Fixes. Disabled bitmap DMA now renders a black VDLP line, the background word uses the correct 8-bit-to-5-bit RGB conversion, live OpenAL device switching keeps each output's context, and the Settings test tone no longer crackles from sleep-granularity gaps.

Validation

• Full suite 1,905/1,905 passes in Debug.
• Build: 0 warnings, 0 errors. dotnet format --verify-no-changes and jb inspectcode --severity=WARNING are clean.
• 50-title differential panel: 50/50 captured, 32/50 match every frame hash at 60/120/300, every sample delta within 9. Space Ace, Wolfenstein 3D, Alone in the Dark, and Lemmings match Opera at 3,000 frames; Road Rash still diverges.
• Windows x64 is the validated target. Linux x64 full-suite and CLI/frontend smoke pass; GPU presentation remains preview/best-effort under llvmpipe/SSH. macOS and arm64 bundles are cross-published and architecture-validated.

Download

System	Bundle
Windows x64	5do-1.4.0-win-x64.zip
Windows arm64	5do-1.4.0-win-arm64.zip
Linux x64	5do-1.4.0-linux-x64.tar.gz
Linux arm64	5do-1.4.0-linux-arm64.tar.gz
macOS x64	5do-1.4.0-osx-x64.tar.gz
macOS arm64	5do-1.4.0-osx-arm64.tar.gz

Each bundle contains the framework-dependent single-file CLI and desktop app, the README/license/notices, whatsnew.md, and the release/legal docs. Install the .NET 10 Runtime first; the bundles do not include the runtime.

See the full release notes and release page for SHA256SUMS.txt.

Known limits

• Run-ahead is CPU-bound and incompatible with rewind history and deterministic movie recording/playback; the frontend disables those features while it is active.
• VRR depends on the GPU, driver, monitor, and desktop; 5DO only avoids the blocking swap interval.
• The online cover catalog is optional and is not included in any release bundle.
• The differential panel still has unresolved PC/CPSR phase and CD-cadence differences; frame-hash matches are evidence, not a full accuracy claim.