u9hx@vax5.cit.cornell.edu (03/12/91)
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
sguerke@brahms.udel.edu (Stephen Guerke) (03/13/91)
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 that I support, who used DD density diskettes formatted HD for backing up data, had data on one of the diskettes just sorta fade away, he has since invested in HD diskettes and transferred his surviving data.
py@meadow.uucp (Peter Yeung) (03/13/91)
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 A friend of mine actually drill the small hole which indicates a HD diskette, he has one of those cheapo "drill press" which convert your power drill into a mini drill press. He uses a lot of them regularly and never seems to have any problem with the converted HD diskettes. BTW, he is using the diskettets on an Apple IIfx. -- Peter Yeung Amdahl Canada Ltd., Software Development Center 2000 Argentia Road, Plaza 2, Suite 300 Mississauga, Ont. L5N 1V8 Phone: (416) 542-6300 Fax: (416) 858-2233
marc@isy.liu.se (Marc Ahlse) (03/13/91)
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. As you probably know, that's what way they do with modern sewing machines, cripple them and sell them as a 'budget offer'. marc@isy.liu.se
klingler@triton.unm.edu (David Klingler) (03/14/91)
I've been using very generic 720k disks (from MEI at $0.39) at 1.44 for about 9 months now. No problems so far, but it may be to early to tell. Needless to say I have backups on 5.25 1.2m diskettes. BTW, I bypasses the notcher method and installed a switch on the back of my computer that switches pin 2 on the floppy drive High or Low (sort of like bypassing the notch sensing switch).
ntaib@silver.ucs.indiana.edu (Nur Iskandar Taib) (03/16/91)
>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 >that I support, who used DD density diskettes formatted HD for backing >up data, had data on one of the diskettes just sorta fade away, he has >since invested in HD diskettes and transferred his surviving data. I remember an ad for one of these a while ago claiming that the person who invented the disk driller examined the media on DSDD and DSHD diskettes and couldn't find any difference. Sounds fishy to me... I did use to use SSDD diskettes as DSDD, and had few problems, but thats another set of problems altogether (DOS Format will mark bad spots, but it can't do much about fading data!). One use for "pushed" diskettes would be for storing all those GIF files and shareware you download and never use, but _think_ you may use one day.... -- ------------------------------------------------------------------------------- Iskandar Taib | The only thing worse than Peach ala Internet: NTAIB@AQUA.UCS.INDIANA.EDU | Frog is Frog ala Peach Bitnet: NTAIB@IUBACS ! -------------------------------------------------------------------------------
cctr132@csc.canterbury.ac.nz (Nick FitzGerald, CSC, Uni. of Canterbury, NZ) (03/16/91)
In article <marc.668819304@rainier>, 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
mcastle@mcs213e.cs.umr.edu (Mike Castle {Nexus}) (03/17/91)
A friend of mine uses a drill press to notch his disks. He's only had one disk
go bad on him, but more disks that cracked along the seam when he drilled it.
He didn't mention any problems with getting filings on the disk and messing it
up. He's also considered putting a switch in to replace the sensor. He'll be
glad to here others have already done that.
I would suggest trying to use FDFORMAT to squeeze more space out of disks. I'm
not sure if it actually tries to push more data into an area (like HD formatting
does) or if it just rearranges the information on the disk so that it's placed
on there more effeciently. I use it to format 360K 5.25s at 591K, and it works
fairly well. I've got flaky disk drives though, and no one can read these disks
on their machine (with RDREAD or w/o), similarly, I can't read non-standard
disks in mine, though others can read them on other machines. It also refuses
to do ANYTHING with my 3.5" drive (including a standard format). I haven't
tried version 1.60 yet. It's available on simtel-20 et al as FDFRM16A.ZIP
in pd1:<msdos.dskutl>.
As far as whether the media on HD and DD disks are different or not, I say they
are very much different. If you want, get a standard HD and standard DD disk,
open the window on it, and hold it up to a light. You'll noticed a BIG
difference in the way they appear. Definitely looks like different media to
me.
--
Mike Castle (Nexus) S087891@UMRVMA.UMR.EDU (preferred) | XEDIT: Emacs
mcastle@mcs213k.cs.umr.edu (unix mail-YEACH!)| on a REAL
Life is like a clock: You can work constantly, and be right | operating
all the time, or not work at all, and be right twice a day. | system. :->