Well here's a quick question, will this system see your HD20 (since we know it reads HFS files) and if so, does it also see your 800K drive daisy-chained through the HD20? Reading it should cause no problems, but I sure wouldn't write anything to it! If so, that answers part of my question without trying to reformat your drive. If not, then it likely won't be able to reformat it either. It's more of an experiment than practical application. Though if you use the HD20 mainly for applications and disk images, a flat file system wouldn't be so bad.