Apple has released Mac OS 9.1, the latest version of it’s shipping operating systems for Macintosh computers. Mac OS 9.1 improves support for Multiple Users and iTools, but also offers a number of under the hood enhancements including AppleScript 1.5.5, AppleShare Client 3.8.8, OpenGL 1.2, revised FireWire software, a new process manager (enabling faster task switching and better performance of some background applications), and a substantially revised nanokernel. Mac OS 9.1 also improves the Finder’s Get Info functionality, adds a Window menu to the Finder, and simplifies the top-level folder structure of a newly set up drive to more closely match that of Mac OS X – installing only System, Documents, Apple Extras, and Applications (where things like Utilities and Assistants have been moved).
Mac OS 9.1’s system requirements are unchanged from Mac OS 9: an Apple original PowerPC-based system with at least 32 MB of RAM (64 MB of RAM or more recommended). Apple does not support third party PowerPC upgrades; although Mac OS 9.1 may work with them, you may wish to let more-ambitious users test the waters first before trying it yourself. Also, Mac OS 9.1 and the Mac OS X Public Beta are not compatible; Mac OS 9.1 breaks Mac OS X Public Beta’s Classic environment.
The Mac OS 9.1 Update for U.S. English systems is available online for free, but it’s a substantial download: nearly 70 MB for 15 segments or a single file (available shortly). A better option for many users may be to order a CD; Mac OS 9 owners in the United States can order a full Mac OS 9.1 installation CD for $19.95 from Apple if they can provide one of Apple’s proof of purchase coupons or a copy of a dated sales receipt. Please note that owners of early NuBus Power Macs and Workgroup Servers must use a complete install CD to upgrade to Mac OS 9.1. Apple plans to release localized versions of the Mac OS 9.1 Update shortly. Similarly, if you use a Language kit with Mac OS 9, you must have the full Mac OS 9.1 CD to update your language kit. As with any system software update, be sure to perform a complete backup before installation: it’s just common sense.