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gase 0.1.0

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@github-actions github-actions released this 10 Oct 17:14
v0.1.0
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Learn about vigilant mode.

The first release: a complete, tested Mega Drive / Genesis emulator.

Emulation

  • Motorola 68000 (gase-m68k): full instruction set with exact cycle
    timing, 2-word prefetch queue, microcode-accurate address-error frames,
    interrupts, trace, STOP/RESET/TAS, pre-decoded dispatch table and a
    Motorola-syntax disassembler. Validated against the MAME-derived
    SingleStepTests suite (310,000 vectors) and Tom Harte's suite.
  • Zilog Z80 (gase-z80): full documented and undocumented behaviour
    (WZ/MEMPTR, Q, X/Y flags), interrupt modes 0/1/2, disassembler. Passes all
    1,604,000 SingleStepTests vectors, ZEXDOC and ZEXALL.
  • VDP (gase-vdp): planes, window, sprites (limits, masking,
    collision), shadow/highlight, interlace mode 2, HV counter, interrupts,
    4-entry write FIFO, per-line access slots and time-accurate DMA.
  • Sound (gase-sound): YM2612 (log-sin/exp tables, envelope
    generator, all algorithms, SSG-EG, LFO, CSM, DAC, ladder effect), SN76489
    PSG, polyphase sinc resampler, model-1 low-pass filter, DC blocker.
  • System (gase-core): memory maps for both CPUs, master-clock
    scheduler, cartridges (header, .smd, battery SRAM, serial EEPROM for
    Sega/Acclaim/EA/Codemasters boards, SSF2 mapper), 3- and 6-button pads,
    NTSC/PAL regions, save states, rewind.
  • Optional lenient mode for 68000 address errors (--no-address-errors)
    for buggy homebrew.

Frontend

  • SDL2 window: aspect-correct scaling, fullscreen, gamepads, save-state
    slots, rewind, fast-forward, pause/frame advance, screenshots, battery-save
    autosave, audio-driven pacing with dynamic rate control.
  • Built-in learner debugger: CPU registers and disassembly, decoded VDP
    registers, palettes, tile/plane viewers, sprite list, breakpoints,
    stepping, per-channel audio mutes.
  • Headless runner without any external dependency: benchmarks, PNG
    screenshots, WAV recording, instruction traces, VRAM/CRAM dumps,
    breakpoints.

Performance

  • 1.5–1.9× faster than the first working version with bit-identical
    output; about 25× real time on one core. Every fast path keeps a readable
    reference implementation and a test proving they match. Measurements and
    scripts live in benchmarks/.

Quality

  • Zero external dependencies outside the optional SDL2 frontend,
    forbid(unsafe_code), clippy-clean, documented crates
    (docs/ARCHITECTURE.md).
  • CI on every pull request (fmt, clippy, tests, docs, dependency-free
    build) and weekly runs of the CPU test vectors and the test-ROM frame-hash
    regression suite.

Downloads

File For
*-linux-x86_64.tar.gz Linux (x86-64, glibc 2.35+). Run ./gase; SDL2 is built in.
*-windows-x86_64.zip Windows 10/11 (x86-64). Run gase.exe.
*-macos-universal.tar.gz macOS 11+ on Apple silicon and Intel. Not notarised: run xattr -d com.apple.quarantine gase once.
SHA256SUMS.txt Checksums of the files above.

The source code is attached by GitHub below. Desktop builds include SDL2 (zlib licence).

Assets 6
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