Mac OS (Classic)
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This article is about the Mac OS prior to Mac OS X. You may be looking for information about the Classic Environment, the Mac OS 9 emulator in Mac OS X.
Mac OS (Classic) is a colloquial name for versions of Mac OS prior to 10 (Mac OS X).
Earlier versions of the System Software from 1984 to early 1987 were not titled as 'System Software'; the unified version names started with System Software 5 (System 4.2). However, despite the unified name, the Finder and the System versions are rarely in sync with each other.
The first version of Mac OS was bundled with Macs in early 1984. In May of that year, it was replaced by System 1.1 which featured improvements such as a speed increase while copying disks and bug fixes in graphical demos.
System 2 was introduced in April 1985, and featured a much improved Finder (which jumped from version 1.1g to 4.1).
Introduced with the Mac Plus in January 1986, System 3 introduced, among other things, the HFS (Hierarchical File System) which replaced the MFS (Macintosh File System). The new file system featured support for folders extending beyond the root level of a disk. With the Macintosh File System, there were two 'levels'-- the root level of the disk and folders inside that. Any folders beyond that were virtual folders, and stored in a data file that the computer read. HFS allowed for true nesting of folders. System 3 had several updates, Systems 3.1, 3.2 and 3.3.
System 4 was introduced in March 1987. It had no significant new features, but fixed a number of bugs in Systems 3.2 and 3.3.
In October 1987, System Software 5 was introduced, featuring MultiFinder and Color QuickDraw. It was the first version of Mac OS to have a unified System Software version (5.0) rather than separate versions for the System and Finder (System Software 5.0 included System 4.2 and Finder 6.1).
System 6 through 6.0.8
System 6 featured true 32 bit memory addressing. Additional versions, up to 6.0.8, were released over the next few years to support newer Macintosh models.
System 7 through 7.1.1
Released in May, 1991. New features included:
- 32-bit operating system
- Co-operative multitasking
- Virtual memory support added
- Quicktime introduced
- AppleScript introduced
System 7.5 through 7.5.5
System 7.5 saw a confusing bombardment of updates to fix bugs and fix the bugs those bug fixes created!
- System 7.5.1 was a minor update with some fixes.
- System 7.5.2 included support for newer, PCI-based, PowerMacs and certain PowerBook models. Also included bug fixes present in 7.5.1.
- System 7.5.3 was an update which could be applied to any previous version of System 7.5. It included some big changes to the OS as whole and introduced a few bugs on the way. Came pre-installed on several mac models.
- System 7.5.5 released to fix the bugs introduced in 7.5.3. Not all machines supported this update, so users of some models had to stay with a buggy 7.5.3 or wait until the release of 7.6.
- Can be found on Apple's old software page for free download
Mac OS 7.6 through 7.6.1
- More PowerPC code in this release, indeed, before OS 8, this was the primary System Software to run on PowerPC based Macs.
- Is not offered as a free download from Apple due to copyrights that Apple included within the System.
- Is the first time Apple used the name "Mac OS", replacing the traditional "System" moniker.
Mac OS 8
- Finder gained 'multithreading'. It was now possible to copy multiple files and open documents simultaneously.
- The general appearance changed from black and white to 'Platinum' using various shades of grey to give a 3D/metallic view.
- Spring loaded folders
- This was the last system to support reading from the MFS. Creating MFS disks had been dropped in System 3, when MFS was replaced with HFS.
Mac OS 8.1
- The last system to be compatible with the 68040 processor.
- Introduced HFS+ as a new file system format that allowed for smaller file sizes and more files per drive. Today, we use a slightly modified version of HFS+ (HFS+ with Journaling) however the disks will still read in a OS 8.1 computer.
Mac OS 8.5 through 8.6
- Sherlock application. Used for searching various internet services as well as local disks.
- OS 8.6 brought numerous performance and stability benefits.
Mac OS 9 through 9.2.2
- Support for 'iTools' (later renamed .Mac)
- Automated Software Update function to keep your mac up to date.
- Multiple user accounts
- 9.1 or 9.22 (preferred) for use as classic support under Mac OS X
- The last Classic OS.
Eric Rasmussen's .Mac homepage An excellent history of the mac system software before System 7.
Wikipedia's System 6 page.
Wikipedia's System 7 page.