Your drive is almost dead and needs replacing. To restore, boot the 10.5 installer disc with the Option key, and use the Time Machine restore option under Utilities after replacing the hrad drive.
http://www.macsales.com/ has 2.5" Parallel ATA IDE hard drives you can replace the one in your Powerbook.
Haven't found the Leopard disk yet - I moved - and the Tiger boot disk offers no such option. I'd rather not replace the disk unless I have to, since I'll be getting a new machine soon, and I'm not sure the disk is really failing. The disk is old, it could be failing, but I have a couple of reasons to try to fix it.
1. There were some power outages and it's possible something got corrupted.
2. I'm not sure restoring from Time Machine will work. I can get TM to restore individual files, but there seems no way to do an erase/format/restore on the current disk even though the TM backup is on another drive.
3. I just miss working with Unix and would like to learn to fix this myself.
I have got a FireWire OWC drive, maybe I can format and install to it and use it as a boot disk?
It is NetBSD based with some components of AT&T Unix. That said, the permissions are a tangle compared to some Unix systems, and you can royally mess yourself up trying to untangle them for anything but folders you create yourself.
You could as you say format the Firewire drive. I would make a second partition for when you do find the 10.5 installer, so you can recover the entire backup with Time Machine. Don't forget, many things that may have been upgraded to 10.5 won't work with 10.4. So you are in a bit of a bind until you find that 10.5 disc.
The Apple Store could put your machine in Target mode and recover everything with their copy of Time Machine, if you want to work with them on that. Also a nearby http://www.apple.com/usergroups/ usergroup might have someone who has the discs or at least the ability to do what the Apple Store can.
Found the disk. Last night I used it to Repair the backup drives, as the boot drive was still unfixable. I have a couple of options - there's a Firewire disk with some year-old Time Machine backups, and a newer USB drive which has current TM backups on one of its partitions, plus an image backup from last year.
I might as well format and reinstall on the internal drive, as that preserves all the backups, and see if the hard drive is truly failing. That laptop has just been a stellar piece of hardware - it's been my daily workhorse since January 2005! I've never had any other computer give me eight years of reliable service.
I confess I'm puzzled about Time Machine. It has a restore button, and when I selected a date from a month ago (thinking that recent backups might hold a corrupted file due to the hard drive problem) it prompted me to select a destination. I didn't see any option for a full restore. Is that because TM is smart enough to know that only one file had changed?
It might be better to not put all the junk back on - to do the fresh install, then just reinstall the programs I use regularly. I'd like to get all my mail back. Can I use Time Machine to selectively restore specific programs, or say, just the user data files? Isn't there a decent online reference for Time Machine where I can read up instead of asking for help?
It seems like Apples's got to be refreshing or coming out with new versions of the Mini, which is the replacement machine I want, so I hate to spend a lot on the old machine.
Thanks for all your advice - I appreciate the help.