CLK
CLK, or Clock Signal, is an emulator written and maintained by Thomas Harte. It first acquired support for CPC emulation in late 2017. It was originally available only for macOS but now also has a command-line based Linux/SDL port.
It emulates the old generation hardware only but seeks to be cycle perfect in its attempts to do so, right down to producing a 1Mhz audio feed and simulating a spinning platter and a fixed head for disk access. Since it has some known incompatibilities, it does not yet fully succeed.
Unlike many emulators, it is not frame-centric, emulating a CRT surface and reproducing its current state in time with the host machine.
Therefore if you have a 144Hz monitor and 192kHz S/PDIF audio output, this emulator will produce 144 different frames each second from the emulated CPC and provide PSG output at 192kHz.
In addition to the CPC, it also emulates the Acorn Electron, Atari 2600, ColecoVision, Commodore Vic-20, MSX 1, Oric 1/Atmos and the Sinclair ZX80/81, and seeks to offer all as complete turnkey systems: just open a media image and it'll figure out the target machine, that machine's proper configuration and any commands necessary to launch the media, then it will launch the software contained on the media. The emulator's job is to be as inconspicuous as possible, allowing the user simply to enjoy the work of classic-era authors with no prior knowledge of the emulated machine in use.
It therefore seeks to be the antithesis of the heavily-chromed ostentatious emulators: to be an invisible link in the user's enjoyment of a piece of software.
