Mac OS 8.1: http://www.info.apple.com/usen/macos8.1/
Mac OS 8.5: http://www.info.apple.com/usen/macos8.5/
Mac OS 8.6: http://www.info.apple.com/usen/macos8.6/
Mac OS 9.0/9.1 : http://www.info.apple.com/usen/macos9/
Please be aware that issues and solutions for Older System Software found in the Knowledge Base have often been solved in more recent releases of System Software. Therefore, it is recommended that you run the most recent system software on your Macintosh.Technical Information can be found in the Knowledge Base: To find articles that relate to your Operating System you can search the Knowledge Base or Knowledge Archive. For assistance in using the Search option to the best advantage please use the Knowledge Base Help option. The Knowledge Base http://kbase.info.apple contains recent updated documents from approximately January 1998 to today.
The Knowledge Archive contains articles covering older Apple products (select the "Archive" option at the search screen). Archived documents are not updated.
The Knowledge Archive articles featured below relate to System 7 and later versions of the Macintosh Operating System.
Document Number 30152: Mac OS: Upgrading from Older OS Versions
This article lists different options for obtaining various version of System Software, System Upgrades and Mac OS Software.
Document Number 15582: Macintosh: System Software Version History
This article contains a history of older versions of Macintosh System SoftwareDocument Number 21176: System 7: 7.5.3 and Later Enabler Matrix
Document Number 20249: System 7.5: Updates, Versions, & What's Installed
This article lists all Macintosh cpus and the versions of System 7.5.3 and later that they support. It also lists current versions of required enablers.
If you are confused about System 7.5 and its updates please read this article archive article 20081: What Updates Do I Need for System 7.5.5?
Questions and answers for customers who had System 7.5.3 pre-installed on their hard drive.
Download System 7.5 version 7.5.3 full install from http://www.info.apple.com/support/oldersoftwarelist.html
Document Number 20408: System 7.5.5 Update: Frequently Asked Questions (1 of 2) contains the answers to frequently asked questions (FAQ) about System 7.5.5 Update. Download System 7.5.5 from Older Software downloads.
Many Customers with older Macintosh computers ask Apple where they can find Mac OS 7.6. Document Number 26170: Where to get Mac OS 7.6 and 7.6.1
Software Updates can be found in the Software Updates Library:
Software updates for earlier versions of Mac OS and Apple hardware are available by browsing the Downloads Web site. You can look at the Older Software Downloads page for a list of all software released prior to January 1998.
Document Number 14724: Where to Find Apple Software Update explains where to find Apple Software Updates that are available for downloading.
Browse the Apple II and Apple IIGS Directory
Browse Older System Software Directory
Apple Discussions Forum
Use this link to go to the Mac OS Discussion Forum.
If you're new to Discussions, use the Help link under Options.
User Groups:
User groups offer the greatest support bargain for most computer users. Within a user group you'll find some of the most helpful and knowledgeable computer experts, and they're willing to share their experience and advice. In addition, many user groups schedule speakers and events that give you a chance to keep up-to-date and learn more about the possibilities of your computer. Please visit Apple's User Groups Locator web page.