The Amstrad CPC (short for Colour Personal Computer) is a series of 8-bit home computers produced by Amstrad between 1984 and 1990. It was designed to compete in the mid-1980s home computer market dominated by the Commodore 64 and the Sinclair ZX Spectrum, where it successfully established itself primarily in the United Kingdom, France, Spain, and the German-speaking parts of Europe.
The series spawned a total of six distinct models: The CPC464, CPC664, and CPC6128 were highly successful competitors in the European home computer market. The later plus models, 464plus and 6128plus, efforts to prolong the system's lifecycle with hardware updates, were considerably less successful, as was the attempt to repackage the plus hardware into a game console as the GX4000.
I tried two emulators of CPC: Arnold, ported by Richard Bannister and MacCPC by Flynn. Arnold is working very well on my OS X Yosemite but MacCPC launches with black screen only. It's working OK on Snow Leopard.
There is also an emulator written in Java, JavaCPC. I haven't tried it but You can download it from CPC-Live site.