[comp.sys.mac.misc] Format floppy disks

cyang%peruvian.utah.edu@cs.utah.edu (Cheng Yang) (08/28/90)

The floppy disks formatted by a Macintosh cannot be
reformatted by an IBM PC.  And the floppy disks formatted
by an IBM PC can't be reformatted by a Mac.  Does anyone
here have any idea of solving this problem?

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marc@Apple.COM (Mark Dawson) (08/28/90)

In article <1990Aug27.110119.2908@hellgate.utah.edu> cyang%peruvian.utah.edu@cs.utah.edu (Cheng Yang) writes:
>The floppy disks formatted by a Macintosh cannot be
>reformatted by an IBM PC.  And the floppy disks formatted
>by an IBM PC can't be reformatted by a Mac.  Does anyone
>here have any idea of solving this problem?
>
When I was working with Kennect, making the Rapport product, we ran into this
problem ALL the time (we had to test if we could do IBM formats, etc).  We
ended up just buying a big magnet ($10 or so??).  It tended to scrable the
data/format nicely, and the Mac && IBMs would then format it.

Mark


-- 
---------------------------------
Mark Dawson                Service Diagnostic Engineering
AppleLink: Dawson.M

Apple says what it says; I say what I say.  We're different
---------------------------------

jdic@uhura.cc.rochester.edu (Jonathan Dick) (08/28/90)

In article <1990Aug27.110119.2908@hellgate.utah.edu> cyang%peruvian.utah.edu@cs.utah.edu
  (Cheng Yang) writes:
>The floppy disks formatted by a Macintosh cannot be
>reformatted by an IBM PC.  And the floppy disks formatted
>by an IBM PC can't be reformatted by a Mac.  Does anyone
>here have any idea of solving this problem?
>

I've never had any problem reformatting Mac 3.5" disks as IBM, or IBM 3.5"
disks as Mac disks.  I don't know why you're having difficulty.  Assuming
you're using 3.5" drives on both machines.  :-) What are the densities of
the diskettes and the drives you're using?

Matter o' fact, I have occasionally saved a diskette that failed
initialization on the Mac by first reformatting it on a PC, and then
trying the initialization again on the Mac.  (I don't recommend this for
any disk you need to rely on, but it's good for a scratch disk...)

-Jon

--------|\----o--------------------------------------------------------------
       |  \    o  | Jonathan Dick                 jdic@uhura.cc.rochester.edu
   |\ /    .\ o   | University of Rochester       Standard disclaimers apply.
   | |       (    |----------------------------------------------------------
   |/ \     /     |
       |  /       | Today's cannibals, putting the "feed" back in "feedback."
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dhoyt@vw.acs.umn.edu (08/28/90)

In article <44308@apple.Apple.COM>, marc@Apple.COM (Mark Dawson) writes...
>In article <1990Aug27.110119.2908@hellgate.utah.edu> cyang%peruvian.utah.edu@cs.utah.edu (Cheng Yang) writes:
>>The floppy disks formatted by a Macintosh cannot be
>>reformatted by an IBM PC.  And the floppy disks formatted
>>by an IBM PC can't be reformatted by a Mac.  Does anyone
>>here have any idea of solving this problem?

  Am I missing something?  I swap disks all the time and have never had a
problem.

david paul hoyt | dhoyt@vx.acs.umn.edu | dhoyt@umnacvx.bitnet

fswrr@acad3.fai.alaska.edu (rector walter r) (08/30/90)

In article <1990Aug27.110119.2908@hellgate.utah.edu>, cyang%peruvian.utah.edu@cs.utah.edu (Cheng Yang) writes...
>The floppy disks formatted by a Macintosh cannot be
>reformatted by an IBM PC.  And the floppy disks formatted
>by an IBM PC can't be reformatted by a Mac.  Does anyone
>here have any idea of solving this problem?
> 

Get a big magnet and apply liberally tohe disk. This usually seems to work.
	-Reed

lrm3@ellis.uchicago.edu (Lawrence Reed Miller) (08/31/90)

In article <1990Aug27.110119.2908@hellgate.utah.edu>, cyang%peruvian.utah.edu@cs
.utah.edu (Cheng Yang) writes...
>The floppy disks formatted by a Macintosh cannot be
>reformatted by an IBM PC.  And the floppy disks formatted
>by an IBM PC can't be reformatted by a Mac.  Does anyone
>here have any idea of solving this problem?
>

Start reformatting the disk to the format that it is already in, and when it
is about half done, hit the interrupt switch and crash your machine (:^()!
The disk will then be "damaged" according to the mac, and you can put it in
any format that you want.  For instance, for a mac disk do "erase disk", and
after about 10 secs of formatting, crash & reboot.  AFE will then reformat for
a PC.  NOTE: There must be a better way of doing this!!!  This procedure is not
good for your system file; use at your own risk.

Lawrence Miller

CXT105@psuvm.psu.edu (Christopher Tate) (08/31/90)

In article <1990Aug27.110119.2908@hellgate.utah.edu>,
cyang%peruvian.utah.edu@cs.utah.edu (Cheng Yang) says:

>The floppy disks formatted by a Macintosh cannot be
>reformatted by an IBM PC.  And the floppy disks formatted
>by an IBM PC can't be reformatted by a Mac.  Does anyone
>here have any idea of solving this problem?

Just what do you mean when you say that the disks can't be reformatted?
Is is that the Mac *tries* to format the disks, but invariably fails?  If
this is the case, then the earlier suggestion of brushing the disk liberally
with a permanent magnet may well be your best bet.

However, I'm not sure I understand why you're having this problem.  I have
often reformatted Mac disks as IBM disks, and vice versa, with no trouble.

Check the densities of the disks you're using.  Are they double density (one
notch in the disk) or high density (two notches)?  If you try to format a
high density disk in drives that can't handle them (non-FDHD drives on Macs,
non-1.44 MB drives on IBM's), you'll have a lot of trouble.  The 800K drives
simply can't handle the greater remanence (sort of "strength") of the magnetic
medium on high density disks.

Oh, and just for general usefulness, here's how to force the Mac to reformat
ANY disk when you insert it.  Sometimes the Desktop file gets a bad sector
in it.  When this happens, the Mac will ordinarily try to rebuild the file,
after telling you it has to make "minor repairs."  Because of the bad sector,
this attempt fails, and so the Mac reports "unable to create desktop file,"
and ejects your disk without giving you a chance to "Erase Disk" to fix the
problem.  To get around this, do the following:

Hold down the command, option, caps-lock, and tab keys while inserting the
disk.  (You may also have to hold down shift; I don't remember offhand.)
This forces the Mac to bring up the disk initialization dialog, whether or
not the disk is readable.

-------
Christopher Tate                        |   "Oh wow:  not only is 57
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Internet: cxt105@psuvm.psu.edu          |    - a very sincere math major

whiteheada@yvax.byu.edu (08/31/90)

Use a magnetic bulk eraser such as ones available from Radio Shack.  They
work every time and without going to the extremes of hitting the reset
switch.

Armand Whitehead
BYU

jimb@silvlis.com (Jim Budler) (09/05/90)

In article <90243.104636CXT105@psuvm.psu.edu> CXT105@psuvm.psu.edu (Christopher Tate) writes:

>Hold down the command, option, caps-lock, and tab keys while inserting the
>disk.  (You may also have to hold down shift; I don't remember offhand.)
>This forces the Mac to bring up the disk initialization dialog, whether or
>not the disk is readable.


Command-Option-Tab

Caps-Lock isn't needed.
--
Jim Budler          jimb@silvlis.com       +1.408.991.6061
Silvar-Lisco, Inc. 703 E. Evelyn Ave. Sunnyvale, Ca. 94086