"Invalid memory access"

That appeared in black text on a white background while booting up.

Has my RAM gone bad, or is that something completely different?

 

sounds like bad RAM. If you have more than one chip in your system, try removing one, then the other.

 

K. A guy on MacAddict said that it could be any hardware that it is having trouble interfacing with; since I've been having trouble with my harddisk, could that be it?

 

maybe. it could be anything. RAM is easy to check. If that doesn't work, then eliminate the software variable by booting to a boot CD... if that works, then eliminate each piece of hardware.

 

Already tried booting from the restore CD, that worked fine. However, when I tried to access the harddisk, it crashed out to the CLI.

Now I'm trying Target Disk Mode, but it seems to have locked up the finder on my G4.

Not good :-\

 

Yay! Got it to mount!
Now I gotta back up everything I can before I try to reformat :-\

 

Doesn't mount right now. The firewire icon is moving around the screen as though it should be working, but other than that, it isn't doing anything. Crap.

 

then it's either a bad hard drive or corrupted software on the drive. Backup if you can, then wipe it.

 

Won't boot from the CD anymore. Even when it did, Disk Utility crashed everytime it tried to scan the harddisk. Same with Installer.

Taking it in for repairs tonight.

 

Good idea. It sounds like some hardware swapping and testing is in order.