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Date: Sat, 26 Apr 1997 19:58:29 -0500
To: terry@lambert.org, ksmm@cybercom.net
From: Tony Overfield <tony@dell.com>
Subject: Re: VFAT 32 support in msdosfs
Cc: joa@kuebart.stuttgart.netsurf.de, hackers@freebsd.org
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At 12:41 PM 4/26/97 -0700, Terry Lambert wrote:
>[OEMSR2] machines are capable of reading long-name-in-volume-label FAT
>drives ("VFAT").  But the partitions they use by default, and the
>partition table format, and the MBR and the io.sys/io.dos/msdos.dos
>where the INT 21 interface is instantiated *all* expect VFAT32.  I'm
>not sure that an OEMSR2 INT 21 is capable of identifying and booting
>from a "VFAT" drive at all.

This is nonsense.

FAT32 is a superset of FAT16/FAT12.  The OEMSR2 version of io.sys 
supports all three.  There is not a special version of io.sys 
which only supports FAT32 partitions.

io.sys does not "do" VFAT at all.  VFAT "happens" when the 
protected mode VFAT driver is loaded.  This is why real-mode 
Windows 95 (DOS mode) cannot see or use long filenames.

Of course, io.dos/msdos.dos are irrelevant, since they aren't even 
used when booting Windows 95, they're used when booting your 
*previous* DOS, which might be MS-DOS 5.0.

Why you think that INT 21 is related to any of this remains a 
mystery to me.