What is the difference between an XP formatted floppy and an IBM pre-formatted floppy?

It is difficult to determine what, if any, differences the writer of that warning had in mind.

There are many people who will tell you that there is no difference.

On the other hand, back when there were still usable floppies that had been formatted on older machines, there was a small but significant number of people who reported problems reading floppies that had been formatted on a Win 95 or Win 98 box in their new XP computers. 

There are two explanations (which may, in fact, be different descriptions of the same thing):

Explanation 1

Windows XP expects a Media Descriptor byte in the BIOS parameter block of the boot sector, and it writes this byte to the disk when it formats a floppy.  Older Windows operating systems don't use this byte.  See http://support.microsoft.com/default.aspx?scid=kb;en-us;140060 

Explanation 2

Floppy disks come in different "densities."  Windows XP recognizes both 720 KB floppies and 1.44 MB floppies (these used to be called "double density"), but will only format 1.44 MB disks.  See http://support.microsoft.com/default.aspx?scid=kb;en-us;309623&Product=winxp

Although you actually can buy 3.5" floppies today, they are all (AFAIK) 1.44 MB, and even though some say "IBM formatted," my guess is that they won't work for your BIOS:  http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Delectronics&field-keywords=floppy+disks&x=0&y=0

It's not clear to me that spoofing the Media Descriptor byte with a sector editor would work (and when flashing a BIOS, you usually don't want to be experimenting).  No matter what the Media Descriptor byte says, if XP has laid down the sectors at twice the density, the floppy drive will likely have problems reading data from it. 

If you want to try, see KB 140060 for the media descriptor byte for 720 KB.

You would be safer finding a Win 98 (or Me or 95) machine and formatting the floppy on that box. 

It is difficult to determine what, if any, differences the writer of that warning had in mind.

And I'd bet that warning was written by Gateway before they were bought by ?????????.  Darn, I used to know.

There are many people who will tell you that there is no difference.

True, but I'd bet there is.  It may be there is a difference somewhere else on the diskette that doesn't interfere with normal operations.  I've already seen the KB article, as it was referenced in a post in the old MS newsgroup for XP.general.  And yes, in case you were unaware, it's still there and running.  :-)

On the other hand, back when there were still usable floppies that had been formatted on older machines, there was a small but significant number of people who reported problems reading floppies that had been formatted on a Win 95 or Win 98 box in their new XP computers. 

That's not going to be an issue for me, I've got some Win98 boot disks.  As well as Win95 and real live DOS 6.22.

Floppy disks come in different "densities."  Windows XP recognizes both 720 KB floppies and 1.44 MB floppies (these used to be called "double density"), but will only format 1.44 MB disks.  See http://support.microsoft.com/default.aspx?scid=kb;en-us;309623&Product=winxp

Hey, I'm an old guy, got that under control.   LOL  I started with Atari 800 with 360KB 5.25 floppies.  Still have it too.

When I bought an Atari 1040ST, I used to p*** off a friend of my by bringing him floppies he could read, but couldn't format similar ones on his "so proud of his all-powerful" PC.  But I could format disks to PC specs with no problems.  I had a ball doing that!  ::grin::

Those Atari's could be made to do a lot of things.  I could even format the old Mac 800k floppies, those systems used floppy drives with variable speed motors.  Although I still have a couple Atari's, I also have a PowerMac 6400 that has that type of floppy drive.

In fact.......  I'll have to check.  I think that old Mac will format a PC floppy, and it's up and running.

I must have a couple hundred of the 720k disks in the back room.  In fact, I've got an unopened box of them!

Although you actually can buy 3.5" floppies today, they are all (AFAIK) 1.44 MB, and even though some say "IBM formatted," my guess is that they won't work for your BIOS:  http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Delectronics&field-keywords=floppy+disks&x=0&y=0

The only way we would be absolutely sure is to compare one of those disks with a diskette that's known to be formatted to the IBM specs.  But I'm not buying a box just for that.

FWIW, buying new floppies was more of a rhetorical question/comment at my end.  :-)

It's not clear to me that spoofing the Media Descriptor byte with a sector editor would work (and when flashing a BIOS, you usually don't want to be experimenting).  No matter what the Media Descriptor byte says, if XP has laid down the sectors at twice the density, the floppy drive will likely have problems reading data from it. 

Three things come to mind...  1) I have not found anything yet that says what the capacity of a blank, formatted diskette needs to be.  Which leads me to think, 2) the BIOS install routine is specifically reading something on the diskette to see if you are using IBM diskettes.  I'm not going to speculate as to why it may be doing this, but there's nothing to stop that from being programmed into the routine.  Similar things were done in the 8-bit 5.25 floppies as a means of copy protection.  3) There could be another X number of unused bytes on the floppy that IBM put data on just so routines such as this could force the average user to use IBM diskettes.  Underhanded, yes, illegal, no.  :-)

You would be safer finding a Win 98 (or Me or 95) machine and formatting the floppy on that box. 

Heck, I could even finish installing a new CMOS battery in an old Compaq Presario w/ Xerox's TabWorx interface for DOS and format one there!    LOL

Something I came across in researching your issue was someone else with the same problem, who included the actual warning from the manufacturer of his old laptop:

To me, that suggests that the issue is not that the BIOS needs an "IBM-formatted" floppy, but one that was not formatted by a Windows NT-based operating system.  (But see the post from "Sorinso" in the thread, which suggests a much simpler explanation --> http://www.petri.co.il/forums/showthread.php?t=29398)

If you have those old pre-XP formatted floppies, use one of them -- without formatting it first .  Just copy the BIOS flash file to it.  If when you put the old floppy into a drive on an XP box, XP may complain that it's not formatted and refuse to read or write it.

One thing I didn't include before because it was not quite relevant is a solution that worked for me (to read/write Win 95-formatted floppies on an XP box) was to install a "3-mode driver."

Read this thread --> http://groups.google.com/group/microsoft.public.windowsxp.hardware/browse_frm/thread/26eea73436993134/f57221cfa9ab4d38?hl=en&ie=UTF-8&oe=UTF-8&q=floppy+problems+please+read#f57221cfa9ab4d38 and download the driver at the viaarena link (surprisingly, it's still there).  Install the driver in your XP box, pop in one of those old floppies you have, and go from there.

Something I came across in researching your issue was someone else with the same problem, who included the actual warning from the manufacturer of his old laptop:

Quote:

Note: Do not format the floppy disk in Microsoft Window NT(r), Windows 2000, or Windows XP. Do not use a floppy disk that has been formatted in these operating systems.

To me, that suggests that the issue is not that the BIOS needs an "IBM-formatted" floppy, but one that was not formatted by a Windows NT-based operating system.  (But see the post from "Sorinso" in the thread, which suggests a much simpler explanation --> http://www.petri.co.il/forums/showthread.php?t=29398)

As soon as I started reading this thread, I remembered those 1.2 MB floppies!   :-)  But I wasn't that MS knowledgeable at the time (fortunately) and never really got into that issue of the 1.2 MB floppies.

But...  How do we know that 1.2 MB floppies weren't the IBM formatted floppies of the day?

I found a very interesting site on the history of the floppy disk.  http://www.retrotechnology.com/herbs_stuff/drive.html  I've sent an email to the owner of  the site to see if he can shed some light on this.

If you have those old pre-XP formatted floppies, use one of them -- without formatting it first .  Just copy the BIOS flash file to it.  If when you put the old floppy into a drive on an XP box, XP may complain that it's not formatted and refuse to read or write it.

I wish I did, but I don't.  Every floppy I have is used except for the box of 720k disks I mentioned earlier.

One thing I didn't include before because it was not quite relevant is a solution that worked for me (to read/write Win 95-formatted floppies on an XP box) was to install a "3-mode driver."

Read this thread --> http://groups.google.com/group/microsoft.public.windowsxp.hardware/browse_frm/thread/26eea73436993134/f57221cfa9ab4d38?hl=en&ie=UTF-8&oe=UTF-8&q=floppy+problems+please+read#f57221cfa9ab4d38 and download the driver at the viaarena link (surprisingly, it's still there).  Install the driver in your XP box, pop in one of those old floppies you have, and go from there.

I downloaded the zip file, only to discover it's a "sample" file, apparently a work in progress.  But I did find out there's a number of 3 mode drivers on CNET.   :-)  So that's still an option.

I've got extra desktops around here, I may just install Win95 and see what I've forgotten about floppy disk formatting there.  :-)