Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!decwrl!pa.dec.com!shlump.nac.dec.com!yacht.enet.dec.com!gettys From: gettys@yacht.enet.dec.com (Bob Gettys) Newsgroups: comp.sys.ibm.pc.hardware Subject: Re: 360K in 1.2M drives Message-ID: <20713@shlump.nac.dec.com> Date: 4 Mar 91 20:42:21 GMT References: <1991Mar1.155859.16874@cbnewsc.att.com> Sender: newsdaemon@shlump.nac.dec.com Reply-To: gettys@yacht.enet.dec.com (Bob Gettys) Organization: Digital Equipment Corporation Lines: 23 One way to re-use a floppy without getting into this problem is to bulk erase it with a bulk tape eraser. This destroys the 360k info allowing the 1.2meg sized info to be visible without the old 360k info in the "background". Typically (but not always!) you can use a virgin (or a reborn virgin via bulk erase) floppy to take data from a 1.2meg drive to a 360k drive if the disk is formated as a 360k disk with the 1.2meg drive. This lays down the narrow track without the interference of the wide track in the background. When it won't work it is the result of the signal (remember, there is less of it) is tto weak for the particular 360k drive you are trying to read it on. Also remember to NEVER NEVER write on the floppy with a 360k drive as this will lay down a wide data track that the 1.2meg drive won't be able to write over later. (Then it's time to bulk erase it again!) As for the 3.5 inch ones - the head is the same size on both. The tracks are just closer together on the 1.44meg than on the 720k. Thus the 1.44meg can read and write the correct sized track in the right place for a 720k floppy. /s/ Bob Gettys