The Macintosh Plus was the first real improvement on the Macintosh 128 (The Macintosh 512 was only a Mac 128 with 512 KB RAM).
It had a lot of new features: the extended ROM held the new version of Mac OS, enhanced graphics libraries, drivers for hard-disk and external floppy-disk units, a SCSI bus, AppleTalk networking and the new file manager: HFS (Hierarchical File System).
The new floppy-disk unit could use double-sided 800 KB disks (only one-sided 400 KB for the 128). It had an enhanced keyboard with a numeric keypad and last, but not least, it had a SCSI 1 (1.5 MB/s) interface.
This computer would be succeeded in 1988 by the new Macintosh series: the Macintosh SE and the Macintosh II. However, it stayed in Apple's product line longer than any other Macintosh machine, almost five years, and was on sale until 1990.
END OF PRODUCTION
BUILT IN LANGUAGE
Full-stroke 78 keys with numeric keypad
Motorola MC 68000
1 MB (up to 4 MB) IBM RAM SIMM's as well as any other 1MB SIMM could be added
512 x 342 dots
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
RS 232/422 x 2 for printer and modem, SCSI, external F.D. unit, ext. loudspeaker