High Quality Content by WIKIPEDIA articles! The Spectre GCR was a hardware add-on to the Atari ST computers that plugged into the cartridge port. Designed by David Small and sold through his company Gadgets by Small, it essentially turned the Atari ST into an Apple Macintosh computer. It was the final Macintosh emulator for the ST, and replaced the previous products Magic Sac and Spectre 128.