System 1

First major release of classic Apple Macintosh operating system (1984)

The Macintosh "System 1" is the first major release of the classic Mac OS operating system. It was developed for the Motorola 68000 microprocessor. System 1 was released on January 24, 1984, along with the Macintosh 128K, the first in the Macintosh family of personal computers. It received one update, "System 1.1" on December 29, 1984, before being succeeded by System 2.

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