SkyRoads executable reconstruction

This is an unofficial native Windows reconstruction. SkyRoads and its original assets remain the work of BlueMoon Software/Bluemoon Interactive. See the original credits.

The active porting path is a reviewed C reconstruction of skyroads.exe, not a gameplay approximation. The DOS executable and shipped data files are the authority. Generated decompiler output is evidence; only manually checked code is admitted to the reconstructed library.

The Win32 target under src/ now directly links and runs that reconstruction. Its responsibilities are limited to presenting the recovered 320x200 indexed framebuffer, supplying devices/timing, and playing recovered sample events; the old approximate gameplay and perspective renderer are no longer on the active path. The host also streams the recovered OPL register schedule through a native OPL2 synthesizer.

SkyRoads Native 1.0.2

The first stable release combines the executable-authoritative DOS simulation with optional native enhancements: both 30-road campaigns in one selector, smooth high-definition presentation, recovered OPL2 audio, a visual road editor, spatial editor views, and optional in-level shortcuts. See the complete 1.0.2 release notes and editor manual. Version 1.0.2 includes the self-contained runtime fix introduced in 1.0.1 and adds true recovered-geometry Hi-Def polygons, a polygon player craft, fullscreen support, visible completion counts, and editor/import corrections.

Original game requirement

This repository does not include the copyrighted DOS executable, artwork, levels, music, or sound data. Release builds embed the compressed game archives but deliberately omit the DOS executable. To run the port, place skyroads_native.exe beside a legally obtained original copy of either:

• SKYROADS.EXE, or
• SKYXMAS.EXE.

BlueMoon still hosts the original releases on its official history page:

• Official SkyRoads history and download page
• Download the full original SkyRoads
• Download the full SkyRoads Xmas Special

The site is a preserved period website served over HTTP. Download and extract either official archive, then put skyroads_native.exe beside its DOS executable. Do not rename the original executable.

The Windows host deliberately checks only the folder containing the running native executable. It does not search parent directories or silently use a different installation. No loose .LZS, .DAT, .SND, or .REC files are required at runtime, and the compiler, C++, threading, and synthesis runtimes are linked into the release executable. Users do not need to install Visual C++, MinGW, or any other support library. Startup stops with an explanatory message when neither original executable is present.

Building from source still requires legally obtained SkyRoads archives so CMake can generate the embedded-data translation unit. Point the cache variables at the two original installations when they are not in the default locations:

cmake -S . -B build -G Ninja `
    -DSKYROADS_DATA_DIR="C:\Games\SkyRoads" `
    -DSKYROADS_XMAS_DATA_DIR="C:\Games\SkyRoads Xmas"
cmake --build build

Then copy build\skyroads_native.exe beside either original DOS executable and run it there.

Current recovered source

reverse/reconstructed/ contains reviewed C for:

• MZ startup order, allocation scopes, configuration checksum, and hardware probes
• the exact LZS decoder and streamed CMAP, PICT, ANIM, road, TREKDAT, car, and dashboard-DAT resource layouts
• all four input paths, including byte-exact demo.rec playback
• fixed-point road lookup, physics, ship profiles, collision subdivision, landing prediction/recovery, fuel, oxygen, and level outcomes
• gameplay frame-parameter selection and the VGA TREKDAT road/car draw traversal
• the self-modifying DOS picture-blitter semantics and asset-driven VGA world/dashboard, gauges, warnings, progress, gravity, and jumpmaster rendering
• exact main/settings/help/30-level selection dispatch and menu-cell geometry, plus a native four-column extension for the 30 SkyRoads Xmas levels
• exact intro/demo/main-menu/run-level control flow, including every original timed hold and 36 Hz palette-transition phase
• all five PC-speaker/PCM effects plus the complete 14-track muzax.lzs OPL instrument/event scheduler and original register programming order

reverse/symbols.json is the reviewed address/name map. reverse/generated/ is reproducible output and is ignored by source control.

Build and verify the reconstruction

cmake -S reverse\reconstructed -B reverse\generated\reconstructed-build -G Ninja
cmake --build reverse\generated\reconstructed-build
ctest --test-dir reverse\generated\reconstructed-build --output-on-failure

The standalone suite currently has 29 deterministic regressions for original archives, palette arithmetic, control-flow timing, the full demo-driven gameplay trace, renderer parameters, and asset-driven VGA scenes. One regression compares all 1,702 serialized gameplay states and 51 Sound Blaster-filtered effect events against a trace captured directly from the DOS executable. A second executable oracle compares 1,241 effective OPL2 register changes across 8,510 original 180 Hz scheduler ticks. The root build also has native integration and OPL PCM tests. The DOS framebuffer probe captures all 1,702 complete 320x200 indexed VGA gameplay frames in the original demo. The native reconstruction matches all 108,928,000 captured pixel bytes, including persistent road-buffer transfers, TREKDAT mutations, ship clipping, shadows, and dashboard updates. Additional executable probes cover all 2,048 keyboard masks, 648 joystick threshold and 16-bit-overflow cases, 512 ordered mouse vectors, and 635 distinct VGA DAC states observed from the intro through the demo.

SkyRoads Xmas campaign

When the Xmas archives are supplied at build time, the native port embeds its 30 roads as levels 31–60. The first two selector columns contain the original SkyRoads campaign and the final two contain SkyRoads Xmas. Gameplay loads each campaign's embedded ROADS.LZS records, VGA palettes, and ten WORLD*.LZS backgrounds through the same recovered renderer. Each world entry also uses the thumbnail cropped from that campaign's original GOMENU.LZS artwork; the images are reduced with nearest-neighbor sampling for the four-column 320x200 layout.

Xmas completion counts are stored separately in SKYXMAS.CFG; the original 30-level SKYROADS.CFG layout is left compatible and unchanged. Every selector road shows its saved completion count as a digit. New roads start at 0, and counts above nine are displayed as 9 in the compact layout. The count is bright yellow so it remains distinct from numeric road names.

Built-in custom road editor

Choose EDITOR below the original three main-menu entries to open the creation browser. It scans custom_levels/*.srlevel, lists every saved creation with paging, and includes the new SKYBRIDGE RUN and NEBULA SLALOM demo roads. The ORIGINAL LEVELS folder contains editable copies of all 30 decoded base-game roads, named 1-1 through 10-3. Missing copies are imported from the embedded ROADS.LZS records at startup; valid edited copies are preserved between runs. Custom files preserve the recovered seven-column, 16-bit road-cell descriptors used directly by the original renderer, collision code, and physics.

In the editor, the arrow keys move through the road grid. Press V (or click the view control) to cycle between the editable top-down grid, left isometric, straight road, and right isometric views. The spatial views render the recovered low, middle, and high shape tiers as solid blocks and show ramps as slopes. The numbered material palette or its clickable color swatches selects a road, gap, slow, slide, refill, boost, or terminal brush; Space paints in every view, and a click also paints in the top-down grid. T cycles the six recovered road-shape silhouettes, and W changes the original world theme. G, F, and O adjust gravity, fuel usage, and oxygen usage. Insert duplicates a row, Delete removes one, S saves, and P saves and immediately play-tests the creation through the recovered game loop. Escape returns to the creation browser.

The full browser, painting, spatial-view, metadata, file-location, restoration, and play-testing instructions are in EDITOR_README.md.

Native display and shortcut extensions

The original Settings screen includes a sixth HI DEF control. When enabled, the recovered TREK renderer reports every individual road, wall, ramp, and tunnel face in its original painter order. The host rerasterizes those faces as smooth high-resolution polygons and presents each completed geometry frame atomically through a double buffer. The player craft is replaced by a palette- matched polygon model clipped by the recovered road-visibility mask, so foreground tunnels occlude it correctly. World artwork and dashboard graphics remain pixel-authentic rather than filtered. The verified 320x200 indexed frame and fixed-point simulation remain unchanged underneath. The option is stored in SKYROADS.NATIVE.CFG beside the game.

Press Alt+Enter to switch between the resizable window and borderless fullscreen on the current monitor. Press Escape on the main menu to quit.

During a level, the following native shortcuts are available:

• Ctrl+F12 toggles mid-air jumping and full left/right air steering.
• Ctrl+F11 immediately refills fuel and oxygen.
• Ctrl+F10 toggles zero gravity.
• Ctrl+F9 toggles a 200% recovered-physics speed ceiling.

Port scope

The native target intentionally follows the original VGA branch. The legacy EGA compatibility renderer is documented in the disassembly and symbol map but is not part of this port.

The OPL2 backend uses the pinned public-domain/MIT Opal core described in THIRD_PARTY_NOTICES.md.

Capture and run the framebuffer diagnostic with:

.\reverse\tools\capture_dos_frame_oracle.ps1
cmake -S . -B build -G Ninja -DSKYROADS_ENABLE_DOS_FRAME_ORACLE=ON
cmake --build build
ctest --test-dir build -R skyroads_dos_vga_frames --output-on-failure

Capture the palette and controlled raw-input diagnostics with:

.\reverse\tools\capture_dos_palette_oracle.ps1
.\reverse\tools\capture_dos_input_oracle.ps1

Re-run the executable analysis with:

.\reverse\tools\run_ghidra.ps1