year 1986

The Macintosh Plus computer was the third model in the Macintosh line, introduced two years after the original Macintosh, January 16, 1986. The Mac Plus was the first of many Macintoshes to use SIMMs (single in-line
memory modules) for its memory. It came standard with 1 MB of RAM (four 256 kB SIMMs) and could be upgraded to 4 MB of RAM. It had 128 kB of ROM on the motherboard, which was double the amount of ROM that was in
previous Macs; the new System software and ROMs included routines to support SCSI. Unlike earlier Macs, the Mac Plus’s keyboard included a numeric keypad, and, as with previous Macs, it had a one-button mouse and no fan, making it extremely quiet in operation.