System 4.0 in action
System 4 is the fourth major upgrade of the Macintosh system software. System 4 was first released in January 1987.
Features
System 4.0:
- Was a minor update from System 3, but did have some changes and new features.
- Introduced AppleShare, a file server, as part of the OS.
- Updated the LaserWriter Driver to 3.3.
System 4.1:
- Made for the release of the Macintosh II and SE.
- Updated the LaserWriter Driver to 4.0.
System 4.2:
- Improved the "About the Macintosh" dialog box; now contained RAM usage as seen through Mac OS 9.
- The Color menu was displayed on color capable Macs.
- Backgrounder, DA Handler, Early Access, and Print Moniter were added.
- Cooperative multitasking via MultiFinder was added.
- Updated the LaserWriter Driver to 5.0.
System 4.3:
- Updated the Apple HD SC Setup partitioning software.
- Updated the LaserWriter Driver to 5.1.
