I have an old iMac from 1997 or 1998. It's unusable and has been sitting in my attic for about 7 years. I want to recycle the thing, but I want to wipe the hard drive clean before doing so. As near as I can tell, I need to change my startup disk to something other than the hard drive. But I don't have any of the disks/instructions/etc that came with the computer. Is there any other way (without the sledgehammer) to wipe the hard drive? Free software I can download? If not, can someone tell me how to create a startup disk? Thank you!