The Macintosh Plus computer was the third model in the Macintosh line. It was introduced on 16th January 1986, two years after the original Macintosh and a little more than a year after the Macintosh 512K. It originally sold for $2599 USD. It was discontinued in October 1990.

As an evolutionary improvement over the 512K, it introduced RAM expansion from 1 MB to 4 MB, and the SCSI peripheral bus, among smaller improvements. It originally had the same generally beige-coloured case as the original Macintosh ("Pantone 453"), but in 1987, the case colour was changed to the long-lived, warm gray "Platinum" colour.

Operating system 1.1–2.1, 3.0–6.0.8, 7.0-7.5.5
CPU Motorola 68000 @ 7.8 MHz
Graphic Mode   512 x 342 dots
Monochrome
Tone Generator & Digital-Analog converter (22KHz sampling rate)
Size/Weight  34.5(H) x 24.5 (W) x 27.5 (D) cm / 7.48 kg
I/O Ports   RS 232/422 x 2 for printer and modem, SCSI, external F.D. unit, ext. loudspeaker
One 3.5'' 800 KB disk-drive
OS:   Macintosh System (from 3.2 to 7.5)

Our Mac Plus together with the original keyboard and mouse was kindly donated by Bob Sheppard.

Manufacturer: Apple
Date: 10th January 1986

This exhibit has a reference ID of CH497. Please quote this reference ID in any communication with the Centre for Computing History.