Web site: (not active)
Origin: USA
Category: Desktop
Desktop environment: GUI
Architecture: Motorola 68020
Based on: System 3
Wikipedia: System 4
Media: Install
The last version | Released: 4.3 | November 1987
System 4 – a version of the Mac OS operating system, released in March 1987 by Apple Computer. The System 4 successor is System 5.
System 4.0 was released with the Macintosh SE and System 4.1 first shipped with the Macintosh II—these new machines required additional support for the first expansion slots, the Apple Desktop Bus (ADB), internal hard drives and, on the Macintosh II, external color displays and the first Motorola 68020 processor.
This version shipped with the Macintosh SE and contains the first mention of Macintosh System Software in the included documentation. It includes the update to LaserWriter 3.3 and has the same version of the Finder as the previous version. Because it requires at least 1 MB of RAM, System 4.0 is no longer compatible with the original Macintosh.
System 4.0 was the first release to support color graphics; previous releases did not support color.
