The STacy was a portable version of the Atari ST. It was designed to operate on 12 standard C cell alkaline batteries for portability, but when it was discovered that the batteries only gave about 15 minutes of operating time, Atari glued the lid of the battery compartment shut, compelling users to use the external power supply only.The STacy has features similar to the Macintosh Portable, a version of their Macintosh computer which contained a built in keyboard and monitor.