Clock Signal

What Clock Signal is

Clock Signal, also called CLK, is a free, open-source emulator for Linux and macOS that aims to launch classic software without requiring users to learn an emulator or the original hardware first. It supports systems including the BBC Micro, Apple II, Atari 2600, Commodore Vic-20, early Macintosh, MSX, Sega Master System, and ZX Spectrum. The README describes its Acorn Archimedes, Commodore Amiga, and early PC compatible emulation as less rounded than the other listed systems. CLK can inspect disk, tape, or ROM media to select and configure a machine, issue required commands, and speed up loading where feasible. It does not take ownership of user files and has no import procedure. The emulator processes video signals such as composite video and generates audio at the emulated machine's source rate before filtering it for host output. Its README says audio latency is generally 5–10 ms, while display latency depends on host hardware. CLK attempts cycle-accurate emulation, which its README says succeeds in some cases. A BIOS is required.