System 2

System 2 (System Software 0.3 and 0.5) introduced the second major upgrade to the Macintosh system software. Version 2.0 was released in April 1985 and includes the System 2.0 update, followed shortly after by System 2.1 which provided HD20 HFS support.

Versions of System 2

 * System 2.0
 * System 2.1