Donor: Anonymous
The Macintosh Plus computer being the third model in the Macintosh line was introduced on January 16, 1986. It introduced RAM expansion from 1 MB to 4 MB, and the SCSI (Small Computer System Interface) peripheral bus, among smaller improvements.
The Macintosh Plus was the last classic Mac to have a phone cord-like port on the front of the unit for the keyboard, as well as the DE-9 connector for the mouse; models released after the Macintosh Plus used ADB (Apple Desktop Bus) ports instead.
The Macintosh Plus also had a new 3.5-inch double-sided 800 KB floppy drive, offering double the capacity of previous Macs along with backward compatibility. Unlike earlier Macs, the Mac Plus's keyboard included a numeric keypad and directional arrow keys, and, as with previous Macs, it had a one-button mouse and no fan, making it extremely quiet in operation. The Apple Macintosh Plus was discontinued on October 15, 1990
Reference: http://en.wikipedia.org/wiki/Macintosh_Plus
