jjboritz@violet.waterloo.edu (Jim Boritz) (12/05/88)
A long time ago there was much debate over whether both sides of a single
sided diskette were usable, and whether one could use a single density
diskette in a double density drive. Well, now the question surfaces in
another form.
In the new world of 3.5" floppies the high density diskettes have an
additional hole on the side opposite the protect hole. My 3.5" drive will
not even think about formatting at 1.44Meg unless this hole is present. My
question is, "Can I punch holes in my 720K diskettes and use them at
1.44Meg?"
I am more interested in whether the hardware can withstand this use as
opposed to how the media will stand up to the punishment.
--
Jim Boritz {uunet,utai,clyde}!watmath!violet!jjboritz
University of Waterloo jjboritz@violet.waterloo.eduhutto@killer.DALLAS.TX.US (Jon Hutto) (12/06/88)
>additional hole on the side opposite the protect hole. My 3.5" drive will >not even think about formatting at 1.44Meg unless this hole is present. My >question is, "Can I punch holes in my 720K diskettes and use them at >1.44Meg?" You might, but expect about 500k-720k of errors, or more. You don't know what's under there, first of all, and you don't know how the drive will act when it finds no track there. Will it slip to a different track, and only format 720k, while telling you it did 1.44? Also, the whole may be for MAC single sided drives, so you can use both sides of the disk. I think some places still make disks that way.
rogerson@PEDEV.Columbia.NCR.COM (rogerson) (12/06/88)
I saw a big ad in Computer Shopper about a tool which would punch holes in the low density 3 1/2 inch disks so that they could be used in the 1.44 meg drives. They claimed to have had no reliabilty problems with this at all. They wanted $29.95 (of course) for this wonderful gem of a tool. The tool is probably usefule, but the ad read like a bad Ronco commercial. I will look again and post the address later. Bitte -----Dale Rogerson-----
johnl@ima.ima.isc.com (John R. Levine) (12/07/88)
In article <10208@watdragon.waterloo.edu> jjboritz@violet.waterloo.edu (Jim Boritz) writes: >In the new world of 3.5" floppies the high density diskettes have an >additional hole on the side opposite the protect hole. My 3.5" drive will >not even think about formatting at 1.44Meg unless this hole is present. My >question is, "Can I punch holes in my 720K diskettes and use them at >1.44Meg?" My PS/2 has a 1.44MB drive that doesn't care whether or not a disk has the extra hole. Although the oxide for the DD and HD disks is different, I find that more often than not I can format and use a 720K disk at 1.44MB. Doing so runs the disk/drive combination way out of spec, so I'd use it only for stuff that you wouldn't be heartbroken to lose. (I use mine for my usenet archives.) -- John R. Levine, Segue Software, POB 349, Cambridge MA 02238, +1 617 492 3869 { bbn | spdcc | decvax | harvard | yale }!ima!johnl, Levine@YALE.something Kids spend more time with their parents than parents spend with their kids.
williamo@hpcupt1.HP.COM (William O'Shaughnessy) (12/07/88)
I've had no problem using 720kb 3.5" discs as 1.44 meg discs. I used a soldering iron to make the hole and a one sided razor blade to trim up the excess plastic. If you use a soldering iron to make the hole be sure to do it in a very well ventilated area, since plastic fumes are given off. I've had no detected errors using the 720kb's as 1.44m. I've been using them for 7 or 8 months. Good Luck, Bill O'Shaughnessy No warranties or guarantees are implied or given for any of the above. The above opinions are my personal opinions and may not be those of my employer.
thaler@speedy.cs.wisc.edu (Maurice Thaler) (12/07/88)
My experience with the 3.5" 720K's has been good. I used the solder gun
technique. It is kind of stinky though. Some rather uptight guys on a
local BBS here got into a debate with me about this and somebody pointed
out that they saw an add in Computer Shopper for a device to create the
holes cleanly. I ordered one yesterday. You get the device and 10
un-notched 730K floppies for $29.95. Not a bad deal even if it is
slightly bogus. If you don't like it, they say you can keep the floppies
and return the device for a refund! If anyone is interested, I will post
the ad's 800 number later (I don't have it with me now).
So far, my tests with the solder gun has been NO BAD sectors on 12
pkxarc /t *.arc to test them. So far , after 2 months , no errors.
Maurice Thaler SYSOP Audio Projects BBS (608) 836-9473
SYSOP Power Board BBS (608) 222-8842 jvte@euraiv1.UUCP (Jan van 't Ent) (12/07/88)
jjboritz@violet.waterloo.edu (Jim Boritz) writes: >question is, "Can I punch holes in my 720K diskettes and use them at >1.44Meg?" >I am more interested in whether the hardware can withstand this use as >opposed to how the media will stand up to the punishment. Yes, it *is* possible (if you succeed in punching a not too ragged hole) although there is of course a media difference (double is not high); it is also possible to tape over the hole of a 1.4M disk to use it at 720K (that works for my Olivetti M280 for disks to be used elsewhere). <Jan>
rps@homxc.UUCP (R.SHARPLES) (12/07/88)
In article <6332@killer.DALLAS.TX.US>, hutto@killer.DALLAS.TX.US (Jon Hutto) writes: > >additional hole on the side opposite the protect hole. My 3.5" drive will > >not even think about formatting at 1.44Meg unless this hole is present. My > >question is, "Can I punch holes in my 720K diskettes and use them at > >1.44Meg?" > You might, but expect about 500k-720k of errors, or more. > You don't know what's under there, first of all, and you don't > know how the drive will act when it finds no track there. Will it slip > to a different track, and only format 720k, while telling you it did 1.44? > Also, the whole may be for MAC single sided drives, so you can use both sides > of the disk. I think some places still make disks that way. > I have punched a hole in the top left corner of a Storage Master brand 3.5" disk. It formated out to 1.44 meg with no bad sectors. I copied a bunch of files to it and periodically check them. After several months they are still all there. However, I have had 2 Maxell MF2-HD (1.44mb) 3.5" disk go bad on me. In general, I would not recommend using a product in a manner other than that for which it was designed (e.g. using 720K as 1.44) - unless you know as much or more about it than the manufacturer. But, it has worked so far with my one SM disk. This is not an endorsement of either Storage Master or Maxell, although I would watch out for those Maxell MF2-HD disks if you are using them. Russ Sharples homxc!rps NOTE: The above in NO WAY reflects the opinions of AT&T. These opinions are my own and the results of un-scientific and highly irregular analysis methods.
jcmorris@mitre-bedford.ARPA (Joseph C. Morris) (12/08/88)
In a recent article jjboritz@violet.waterloo.edu (Jim Boritz) writes: > >In the new world of 3.5" floppies the high density diskettes have an >additional hole on the side opposite the protect hole. My 3.5" drive will >not even think about formatting at 1.44Meg unless this hole is present. My >question is, "Can I punch holes in my 720K diskettes and use them at >1.44Meg?" > Punching a hole through the plastic is dangerous: you might crack the plastic shell in the process, but more seriously you will be generating plastic debris where it could contaminate the disk surface and/or the heads on the drive you insert it into. Agreed that the prices for HD diskettes are a ripoff, but there is a simpler way: cripple the circuit in your drive which tests for the extra hole. I've routinely (usually by accident) formatted DD disks to 1.44 mb and have never had any problems with bad sectors. (I make it a point, however, to use HD disks if they will be stored for some time, so I can't speak to the long-term storage characteristics.) I use Verbatim and Sony disks. Neither the PS/2-50's or PS/2-70's I've used made any complaint about formatting the disks to 1.44 mb. The only problem I've had is in getting the disks re-formatted back down to 720K. Hint: some formatters won't change the density once the disk has been formatted at 720K or 1.44 mb. If this happens, it can be fixed by beginning a format run, then suddenly removing the disk from the drive. Brute-force, but it avoids having to get a copy of Norton if one isn't handy.
leonard@bucket.UUCP (Leonard Erickson) (12/08/88)
In article <6332@killer.DALLAS.TX.US> hutto@killer.Dallas.TX.US (Jon Hutto) writes:
<>additional hole on the side opposite the protect hole. My 3.5" drive will
<>not even think about formatting at 1.44Meg unless this hole is present. My
<>question is, "Can I punch holes in my 720K diskettes and use them at
<>1.44Meg?"
<You might, but expect about 500k-720k of errors, or more.
<You don't know what's under there, first of all, and you don't
<know how the drive will act when it finds no track there. Will it slip
<to a different track, and only format 720k, while telling you it did 1.44?
<Also, the whole may be for MAC single sided drives, so you can use both sides
<of the disk. I think some places still make disks that way.
Sorry, but both 720k and 1.44M 3.5" disks have the same number of tracks.
80. The difference is that the 1.44 has twice as many sectors per track.
And while I *still* don't recommend it, I know quite a few people using
DD 3.5" disks in 1.44M drives without any problems. Not all drives check
that hole...
--
Leonard Erickson ...!tektronix!reed!percival!bucket!leonard
CIS: [70465,203]
"I used to be a hacker. Now I'm a 'microcomputer specialist'.
You know... I'd rather be a hacker."land@hpccc.HP.COM (David M. Land) (12/09/88)
I've drilled a couple of discs, originally SINGLE-SIDED (256K) discs for an HP 150, and I'm getting about 90% use from them -- in other words, on a 1.44 M floppy, about 1.3 M of usable space. And that's on a used, single-sided disc. HOWEVER: I only use such discs for files I can afford to lose. ----- What use have I for disclaimers? Nobody listens to me anyway. But if I had one, it would say that I speak only for myself. Mostly TO myself, but what the heck...
is813cs@pyr.gatech.EDU (Cris Simpson) (12/10/88)
In article <5060038@hpccc.HP.COM> land@hpccc.HP.COM (David M. Land) writes: > >I've drilled a couple of discs, originally SINGLE-SIDED (256K) discs for >an HP 150, and I'm getting about 90% use from them -- in other words, on >a 1.44 M floppy, about 1.3 M of usable space. And that's on a used, >single-sided disc. >HOWEVER: I only use such discs for files I can afford to lose. Gosh, it's really shocking to see this from an HP employee, what with all the propaganda they send with storage devices. You know the one with the HP technician saying " If he had used HP disks in this floppy drive, he wouldn't have needed $14,000 worth of service on it." I think I'll call the response center and see if this is supported... :-) cris Disclaimer: I love HP. I've got a lab full of it.