Mac OS 9.2.1

Mac OS 9.21 was released on August 21, 2001.

The update improves Classic application compatibility in Mac OS X and delivers updated support for Macintosh systems that are based on the PowerPC G3 or G4 processor.

Potential problems

 * Apple's language kits are now included with the Mac OS. Versions of Apple language kits prior to Mac OS 9.1 (Language Kits 1.1) are incompatible with Mac OS 9.21. Additionally, users using language kits must upgrade both the Mac OS and the language kits simultaneously.


 * ATM Deluxe 4.6 must be used instead of version 4.5 if the Arabic, Hebrew, Devanagari, Gurmukhi, or Gujarati language kits are to be used.


 * GX desktop printers set up on the hard drives must be dragged to the Trash before Mac OS 9.21 can be installed.

System requirements
Mac OS 9.21 can (officially) only be run on Macs that are compatible with Mac OS X.