The Macintosh Plus computer is the third model in the Macintosh line, introduced on January 16, 1986, two years after the original Macintosh and a little more than a year after the Macintosh 512K, with a price tag of US$2599.[1] As an evolutionary improvement over the 512K, it shipped with 1 MB of RAM standard, expandable to 4 MB, and an external SCSI peripheral bus, among smaller improvements. It originally had the same generally beige-colored case as the original Macintosh ("Pantone 453"[2]), but in 1987, the case color was changed to the long-lived, warm gray "Platinum" color.[3] It is the earliest Macintosh model able to run System 7 OS. The Macintosh plus comes with the external harddrive and the original box. (Serial number is not matching, and the box has been damaged,)