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From: J de Boyne Pollard on 30 Oct 2007 16:19
RP> But, [MS-DOS] 6.22 and later versions (7.00, 7.10, 8.00) have
many
RP> benefits: LFN's, VFAT,

MSS> What is "VFAT"? FAT with LFNs? Then how is it different from
"LFN"s?

It's the name of the VxD that incorporates the FAT filesystem driver
in DOS-Windows 95 et seq.. It isn't a feature of the filesystem, nor
(contrary to popular misconception, that Linux has helped to spread)
is it the name of the filesystem type. That is still FAT. It is
_solely_ the name of the driver module.

Given that it's a VxD, it isn't part of MS-DOS, as claimed.

From: Rod Pemberton on 30 Oct 2007 21:25

"J de Boyne Pollard" <j.deboynepollard(a)tesco.net> wrote in message
news:1193775585.301796.78330(a)t8g2000prg.googlegroups.com...
> RP> But, [MS-DOS] 6.22 and later versions (7.00, 7.10, 8.00) have
> many
> RP> benefits: LFN's, VFAT,
>
> MSS> What is "VFAT"? FAT with LFNs? Then how is it different from
> "LFN"s?
>
> It's the name of the VxD that incorporates the FAT filesystem driver
> in DOS-Windows 95 et seq.. It isn't a feature of the filesystem, nor
> (contrary to popular misconception, that Linux has helped to spread)
> is it the name of the filesystem type. That is still FAT. It is
> _solely_ the name of the driver module.
>
> Given that it's a VxD, it isn't part of MS-DOS, as claimed.
>

Sorry. I've unintentionally listed features available to DOS under Windows
95/98/SE/ME as DOS features. VFAT are the 32-bit FAT routines used by
Windows95/98/SE/ME.


Rod Pemberton

From: Mike Gonta on 31 Oct 2007 05:28
On Oct 29, 6:18 am, "Rod Pemberton" <do_not_h...(a)nohavenot.cmm> wrote:

> This is a serious question. Why would I want to boot a version of DOS prior
> to 6.22?

When you format a USB flash drive in XP as FAT (FAT16) you get a
MSDOS5.0 boot sector.
I tried using the 6.22 system files which are not compatible, the 5.0
files worked fine.

http://mikegonta.com/dosboots


Mike Gonta

look and see - many look but few see

From: Rod Pemberton on 30 Oct 2007 22:10
"J de Boyne Pollard" <j.deboynepollard(a)tesco.net> wrote in message
news:1193777228.451436.132330(a)57g2000hsv.googlegroups.com...
> RP> But, 6.22 and later versions (7.00, 7.10, 8.00) have
> RP> many benefits: [...] FAT32, "FAT32X".
>
> MSS> What is "FAT32X" and how is it different from FAT32?
>
> It isn't.

Oh, but it is. Both the method used to access the disk and the supported
disk capacity are different.

"Two new partition types are defined: 0xB and 0xC. Both indicate FAT32
volumes; type 0xC indicates a FAT32 partition that requires Extended Int 13h
support--that is, logical block addressing (LBA)."
http://www.microsoft.com/whdc/archive/fat32preinstall.mspx

"Using the maximum possible values yields:

512 x 1024 x 256 x 63 (or 512 x 2^24) = 8,455,716,864 bytes or 7.8 GB

The calculation results in a maximum capacity of slightly less than 8
gigabytes (GB). Before BIOS INT 13h extensions drive geometry translation
(also known as logical block addressing , or LBA) were introduced, the
active, primary partition could not exceed 7.8 GB, regardless of the file
system used."
http://www.microsoft.com/technet/prodtechnol/windows2000serv/reskit/prork/prcb_dis_qxql.mspx?mfr=true


> It's just a hokey name for a FAT32 volume that happens to
> live in a type 0x0C partition (as opposed to a type 0x01, 0x04, 0x06,
> 0x0B, or 0x0E partition). The filesystem type is the same, FAT32, in
> all cases. A type 0x0C partition is, simply, supposed to be invisible
> to operating systems that suffer from the 1024 cylinder limitation or
> that cannot handle partitions greater than or equal to 2GiB in size.
> Thus it can begin/extend beyond the 1024 cylinder boundary and be
> larger than 2GiB. This is irrespective of filesystem format. Indeed,
> depending from its size, such a partition could just as easily be a
> FAT16 volume, or even a FAT12 volume, as a FAT32 volume.
>

True, except that I believe you have the wrong limit for the partition size.

> <URL:http://homepages.tesco.net./~J.deBoynePollard/FGA/determining-
> filesystem-type.html#PartitionTypes>
> <URL:http://homepages.tesco.net./~J.deBoynePollard/FGA/determining-fat-
> widths.html>
>

"FAT32X" is FAT32 with LBA, i.e., BIOS extended Int 13h support, for hard
drive capacity larger than 8.4Gb.

Here a summary of MS filesystems (switch to fixed width font):

type max.size max.file clusters max.clust MS-DOS ver. Win. ver.
FAT12 16Mb 2^12 4Kb Ver. 1.00
FAT16 2Gb 2^16 32Kb Ver. 3.00
FAT32 127.5Gb 4Gb 2^28 32Kb Ver. 7.10 WIN95B OSR2
FAT32X * 4Gb 2^28 32Kb Ver. 7.10 WIN95C OSR2.5

NTFS 256Tb 16Tb(16Eb) 2^32(2^64) 64Kb WinXPpro
FAT16 4Gb 4Gb 2^16 64Kb
WinXPpro/WinSrv2003
FAT32X 32Gb 4Gb 2^28 64Kb
WinXPpro/Win2K/WinSrv2003

* 8Tb theoretical, 127.5Gb Win95 & Win98, 2Tb WinME
Win95 & Win98 are FAT table limited, WinME is partition table limited.
FAT32X added extended Int 13h BIOS support for drives >8.4Gb, i.e., LBA.

(The above values came from a number of MS pages - which I didn't keep -
since it was compiled for personal use.)


Rod Pemberton

From: Maxim S. Shatskih on 31 Oct 2007 11:35
> It's not that easy to use Windows if you need DOS. There are some
> differences. Since Win98 you can't even switch back to a DOS command
> prompt without Windows running on top of it. And this DOS delivered with
> Win98 isn't a fully functional DOS.

Win98's recovery diskette is just plain DOS.

--
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
maxim(a)storagecraft.com
http://www.storagecraft.com

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