PowerBook 1400 Update -- TidBITS has received notes from a few readers who have tried to use Disk First Aid and other disk utilities on PowerBook 1400s, but receive a message indicating the PowerBook hard disk is not an HFS disk. (HFS stands for Hierarchical File System, which is used by virtually all Macintosh disks.) This message does not indicate a fundamental problem with your PowerBook 1400; according to Apple, some 1400 systems shipped without a "reference file" these disk utilities use. (I'm puzzled what that file could be, and not having a 1400 I can't easily find out.) Apple has released a simple fix ; if you've seen this problem, apply this update to make disk repair utilities run normally. [GD]