Mirage Imager
From CPCWiki - THE Amstrad CPC encyclopedia!
A addon that enables you to freeze any program and store it to disc. The tool can store backup RAM contents (including CPU registers pushed in RAM), but, unlike Multiface II it cannot backup read-only I/O ports like CRTC (vram address/site) and Gate Array (screen colors) - the include software allows to manipulate that values manually.
Pictures
Manual
Mirage Imager Manual (pdf)