Release 1.5.0

5DO 1.5.0

Released: 2026-11-08

5DO 1.5.0 is an accuracy and presentation update on the 1.4.0 feature release. It moves HQx 2x/3x/4x to GPU rule-table passes, fixes the last panel-wide video divergence, tightens CD interrupt and transfer behavior against Opera, and makes the differential harness report instruction phase and CD cadence directly.

Highlights

• GPU HQx 2x/3x/4x. HQx now runs as a shared rule-table GPU pass in OpenGL/GLES, Direct3D 11, and Vulkan. The CPU implementation remains the reference oracle. 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 is kept as 24-bit RGB through the CPU assembler and all GPU palette shaders, and a zero VDL display-list word is 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. RunFrame ends on the 263/312-line VDL field boundary instead of a rounded ARM-cycle budget, and the harness captures Opera's ARM/CD state in the checkpoint's own video callback. The same-frame instruction delta is 11-20 at frame 60 and 23-2,223 at frame 120.
• CD parity. The Opera poll reset keeps the interrupt enables and POLRE latch, the XBUS CD FIQ is level-held, and READ_DATA validates addresses, aborts stale read-ahead, publishes status with the first sector, and accumulates sector deadlines like the reference. The command-50 boot handoff fell from +207,707 cycles / +86,511 instructions to -818 / -376.
• Diagnostics. New --cd-register-trace and --clio-read-trace CLI traces, harness --timer-trace, instruction-phase and CD-cadence reports, atomic ISO staging, and per-title capture errors instead of panel aborts.
• Launch alias. The desktop shell accepts -fullscreen in addition to -f and --fullscreen; the smoke marker records windowState=FullScreen.

Validation

• Full suite 1,939/1,939 passes in Debug.
• Build: 0 warnings, 0 errors. dotnet format --verify-no-changes and jb inspectcode --severity=WARNING are clean.
• Opt-in Direct3D 11 and Vulkan HQx 2x/3x/4x parity tests pass, as does the WGL/ANGLE HQx probe path.
• 50-title differential panel: 50/50 frame hashes, 0 errors. The 5-title panel matches 5/5 at 300 frames; the 3,000-frame showcase keeps 4/5 (Road Rash remains divergent).
• Windows x64 is 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.

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, 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

• 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.