Recovering Contents of Powerbook 140

[yingpar]

I recently dug up my laptop from 20 years ago, and after a lot of fiddling around I got it to boot up. The screen is flickery, it crashes every third or fourth boot, and the trackball only registers left and right, but to be fair I'm pretty sure it did all these things when I first had it, too.  :O

One thing it does not do, however, is actually get into the Finder. I'm pretty sure there's stuff on this hard drive that would be fun to look at, so I don't want to wipe it completely, but at the moment I can't even do that. What would be the best way to proceed?

 

[beachycove]

The trackball rollers just need cleaning. As for the Finder, do you mean that it will not boot? Do you get a flashing question mark or just a blank screen?

 

[yingpar]

Disk with flashing question mark. I found a floppy disk with "Disk Tools" written on it and tried to boot from that. I get a smiley Mac and it thinks for a while but I end up with an error message that tells me the System file is corrupt and nothing else happens.

 

[Paralel]

The disk you have is most likely not compatible. I have seen that error message before when trying to use an incompatible version of system software with a Mac.

 

[Sherry Haibara]

I second that. You should try using, if possible, another version of the Macintosh System Tools specifically tailored for that machine - anything from System 7.0.1 to System 7.6.1 should be ok. 
If you have any other working machine to make a floppy, you can find 800k and 1.4MB images here.
The question would be if the drive is still working at all - shouldn't there be an existing version of the System installed on the internal hard drive? If that isn't booting, it's entirely possible that the drive is toasted.