Clock Signal

At a glance

• Editor score
  6.0 / 10
• Pricing
  Open source
• Best for
  Mac and Linux users valuing accurate emulation
• Paid from
  Free
• Facts checked
  20 Sep 2026

• Where it wins

  • Supports classic computers and consoles across several system families
  • Single-click media loading with automatic machine configuration
  • Signal-processed audio and video with low-latency output

• Where it doesn't

  • Available primarily through macOS and Linux builds
  • Some systems require original machine ROMs
  • Requires BIOS files for supported systems

Our verdict on Clock Signal

Clock Signal is an open-source desktop emulator for people who want to run software from classic computers and consoles on macOS or Linux. Its supported systems include the Acorn Electron, Amstrad CPC, Apple II, Atari 2600 and ST, BBC Micro, ColecoVision, Commodore systems, Macintosh, MSX, Oric, Sega Master System, Sinclair systems, Tandy CoCo, and Thomson MO5/6. The project is aimed at users who value emulation accuracy, low latency, and reproduction of period-appropriate audio and video behavior.

Its strongest advantage is the combination of automatic setup and detailed output processing. Single-click loading supports disk, tape, and ROM media, while automatic machine selection and configuration reduce the work required before starting a title. Clock Signal also emphasizes cycle-accurate emulation efforts, signal-processed composite video, signal-processed audio generation, and low-latency display and audio output. The native macOS build uses Metal, while SDL and Qt builds use OpenGL, giving the project a platform-specific option alongside cross-platform graphical builds.

Clock Signal is a good fit for Mac and Linux users who want one open-source application covering multiple classic systems and who care about timing and signal characteristics. It is less suitable for users seeking Android support or a broad general-purpose platform footprint. Some emulated systems require original machine ROMs, and those files are not included, so setup may still involve locating the necessary materials. Buyers should choose Clock Signal when accurate multi-system emulation and processed audiovisual output matter more than broad device coverage or a fully self-contained installation.

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Clock Signal pricing

Clock Signal fact sheet

Alternatives to Clock Signal

• RRetroArchA broad, free emulator hub with one interface for collections, cores, controls, and play.9.4
• FoxolFoxol combines multi-system emulation, cloud saves, and multiplayer across web, desktop, and mobile.9.1
• aresA broad, free desktop emulator with preservation-focused tools and system-specific BIOS requirements.8.8

See all Clock Signal alternatives →

Featured on iTechGuides

Clock Signal is listed in our Multi-System Emulators directory. Add the badge to your site — it links back to this page.

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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

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Last updated 7 Oct 2026 · How we research and update