My parents are downsizing and I've been helping clear the house - amongst stuff they've never chucked out are all their old computers (all Macs). The first we had when I was a kid is a Mac Plus, with an external Rodime 20MB (oooooh!) hard drive. After a fair bit of nostalgia playing with it, I'm going to eBay it for them, but my dad wants me to wipe the hard disk first. Fair enough, but doing it securely? My best answer is to delete all the files then copy other mundane things onto the hard disk so the original files are over written. Would this work? It all runs perfectly, though I don't know how well the floppy discs will have held up 25 years on.