Help needed to read IBM 1M formated floppy on something modern.

Geoff Reed geoffr at
Tue Nov 14 17:58:06 CST 2006

-----Original Message-----
From: cctalk-bounces at [mailto:cctalk-bounces at]
On Behalf Of Adrian Graham
Sent: Tuesday, November 14, 2006 1:07 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Help needed to read IBM 1M formated floppy on something modern.

I remembered a discussion here that basically said that despite modern BIOS'
claiming to have 5.25" support the floppy controller itself won't see it
correctly, surprisingly a 1998 Compaq Deskpro EN has the option to declare a
5.25" floppy in the BIOS but it can't address it correctly under Win98, this
may have something to do with being unable to swap the drives over -
normally the 5.25" drive is A: and the 3.5" drive is B:, this upsets the
Deskpro AND Win98 which seem to expect the 3.5" drive to be A: and nothing

Other solutions are bound to be available, YMMV, caveat emptor etc :)

Win 98, and 2000 at least don't care about the capacity of the "a" drive,
I've had 1.2 MB drives on them just fine, I have yet to try with win XP or
2003.  any issues with win 98 and 2000 not being able to read/write a 1.2mb
drive as the 1st drive in the chain lie in the motherboard and bios.

Some of the newer ASUS and Supermicro boards will let you assign a 2nd drive
but you can't read ad write to it :(  been bit by that one a couple times
now.  It turned out that the 2nd drive select line wasn't brought out of the
silicon to the motherboard in the super-IO chips they were using :(

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