Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uunet!comp.vuw.ac.nz!canterbury!cctr132 From: cctr132@csc.canterbury.ac.nz (Nick FitzGerald, CSC, Uni. of Canterbury, NZ) Newsgroups: comp.sys.ibm.pc.misc Subject: Re: DS/DD --> DS/HD 3.5" Disk Notchers Message-ID: <1991Mar16.170405.245@csc.canterbury.ac.nz> Date: 16 Mar 91 04:22:53 GMT References: <1991Mar11.182336.3274@vax5.cit.cornell.edu> <19536@brahms.udel.edu> Distribution: comp Organization: University of Canterbury, Christchurch, New Zealand Lines: 48 In article , marc@isy.liu.se (Marc Ahlse) writes: > sguerke@brahms.udel.edu (Stephen Guerke) writes: >>In article <1991Mar11.182336.3274@vax5.cit.cornell.edu> u9hx@vax5.cit.cornell.edu writes: >>>Does anyone own one of those disk notchers that punches a hole so that you can >>>format a 720k disk into a high density disk? If so, does it really work? How >>>reliable is such device? >>>I have heard stories on both sides, and am trying to decide if I should invest >>>in one myself. Thanks > >>IMHO you're taking a chance. The media on a HD diskette is much >>much more dense than that on a 720K diskette. It is my understanding >>that at the factory(s) the diskettes are tested for density and those >>that pass are marked HD and those that don't are marked DD. I >>wouldn't trust MY data to such a diskette. One of the faculty members > > I've been looking for just such a notcher, any pointers WILL be > appreciated. I know a big company around here that actually uses > one, and they tried to convince me that it worked. So I took a few > samples and tested them. No problem. I guess it's cheaper to produce > one type of media and sell it to two different markets than to have > two different products. [stuff about crippled sewing machines deleted] Here we go again. Basically it comes down to this: Most HD disks have a different media on them than DD disks, but maybe some manufacturers do what Marc is suggesting. Problem is, that there is no easy way to tell which are which, and unfortunately after conducting his large-sample, long-term, statistically significant comparison (this is sarcasm, for those who haven't realised) Marc doesn't tell us which brands are which ( 8-) ). Punching the false "HD hole" in a DD disk (depending on your machine and floppy drive this step is unnecessary), then formatting it HD, reading and writing it for a few weeks will work fine for most DD disks. Problem is, what is reliability like after 3 months, 6 months, a year and beyond. The answer is, that for most DD's you do this to, they become less and less reliable, eventually being completely unusable, without re-formatting. If you are prepared to take this risk (and loss) then fine, it's your life. Given how cheap magnetic media is nowadays, it is false economy. For half the price you can have many times the risk - no thanks. When I copy something off my hard disk to floppy, because I may want it in the future, but can't justify the hard disk real-estate now, I want to be very confident of getting it back, should the need arise. The number of problems I've seen and heard of with failed restores from backups to such disks is enough to put me off anyway. --------------------------------------------------------------------------- Nick FitzGerald, PC Applications Consultant, CSC, Uni of Canterbury, N.Z. Internet: n.fitzgerald@csc.canterbury.ac.nz Phone: (64)(3) 642-337