I tried to upgrade from British OS 8.0 to British 8.1 using the file I had downloaded from the Apple web site. (I have a Performa 5200CD with 24 Mb RAM.) This appeared to be successful but my Mac crashed shortly afterwards. The symptoms were a general slowdown (I could sit and watch the boxes being drawn every time I opened a new folder) until things got so bad the Mac froze completely. I attempted to restart several times (with and without extensions) but kept getting "bus error".
Even after restarting from a locked system floppy (the one which came with OS 8.0) my Mac would still crash if I tried to access files from my hard drive. In the end I had to repair my hard drive three times (once using the version of Disk First Aid from the 8.1 system disk even though the version on my 8.0 disk said that all was OK) and did a clean install of OS 8.0 from my CD. I threw out the previous system folder for good measure.
I was still getting problems (same symptoms) which rebuilding the desktop file and zapping p-RAM (both using TechTool 1.1.7) didn't solve. I have checked for viruses using McAfee and am now at a loss. My system works perfectly (in fact better than ever) as long as I don't activate either the Shared Library Manager or Shared Library Manager PPC extensions at startup - these cause the symptoms I have described and my Mac makes a short, quiet hissing sound just after the "Welcome to Macintosh" screen displays.
The net result is I can't use Open Transport and so can't check e-mail, surf the web, etc. One other strange item of info: the drop-down box in the Modem control panel should offer two options (I think): "Modem Port" or "Printer Port". However, mine offers "Modem Port", "Modem Port" or "Printer Port". This oddity remains after trashing preferences, etc.
Now for the questions:
a) Did I get a bad download of OS 8.1? How can I tell?
b) What should I do to get OS 8.0 working again? Have I overlooked anything? (Please don't suggest reformatting my hard drive!)
c) I updated the drivers during the installation of 8.1 and I'm wondering whether I need to "undo" this step to get 8.0 working again. If so, how do I go about this?
d) Does anyone know of any conflicts with Shared Library Manager? It used to work fine before.
e) Might it be a hardware problem? Could the new memory chip I put in about 6 months ago have gone bad?
f) What good tools are there out there to check for hardware problems?
Most points are on offer for getting Open Transport up and running again, but bonus points are available for satisfying my curiosity.