Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ucbvax!hplabs!hpda!hpcuhb!hpindda!mintz From: mintz@hpindda.HP.COM (Ken Mintz) Newsgroups: comp.sys.ibm.pc Subject: Re: How to write 360K disks in a 1.2MB drive Message-ID: <4330094@hpindda.HP.COM> Date: 6 Jul 88 20:06:21 GMT References: <462@calvin.EE.CORNELL.EDU> Organization: HP Technical Networks, Cupertino, Calif. Lines: 24 > If you buy a copy of the COPYiiPC program, it includes a utility called > BULKERAS. This is a program that will completely blank out a disk. It > works with 1.2M drives as well...it's good insurance before you format your > 360K disks. This leaves me thoroughly confused (again). I understood that the 360K- disk-on-1.2M-drive problem was a physical limitation, namely that the 1.2M heads were narrower than the 360K drives and, thus, failed to overwrite all the magnetic fields. (I suspect subsequent read success on a 360K drive would depend on the sensitivity of the read head.) Degaussing (bulk erasing) works only because it affects the entire magnetic surface, not just the track under the head. But COPYiiPC would have to use the write heads of the drive to "erase" the disk. Thus, I don't see how this could be 100% reliable. Is there something wrong with my understanding? BTW, since you mentioned COPYiiPC: can it "copy" a 1.2M disk if all you have is one floppy drive and a hard drive -- that is, without asking you to constantly switch floppies? The ideal implementation would build a disk image in memory (if there's enough) or on the hard disk, then ask you to switch floppies. Does it work that way? Ken Mintz