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Groups > alt.lang.asm > #6639

Re: The Virtual Partition - say goodbye to FAT12

From "Mike Gonta" <mikegonta@gmail.com>
Newsgroups alt.lang.asm, alt.os.development
Subject Re: The Virtual Partition - say goodbye to FAT12
Date 2016-04-05 15:58 -0400
Organization Aioe.org NNTP Server
Message-ID <ne15em$17vu$1@gioia.aioe.org> (permalink)
References <ndk667$vv8$1@gioia.aioe.org> <ndl7fn$82d$1@gioia.aioe.org> <ndlkec$td5$1@gioia.aioe.org> <ndt9d6$mjd$1@gioia.aioe.org>

Cross-posted to 2 groups.

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"wolfgang kern" wrote:

> What's wrong by using FAT16 instead of FAT12 for small
> systems ?

Hi wolfgang,

What's "wrong" with using FAT12 for small systems?

The Virtual Partition enables the use of the exact same
simple FAT12 driver for an unmodified fully compliant FAT32
volume. What's wrong with that?

The only difference in the driver is that the FAT table
entries are 32 bit instead of 12 bit. As a bonus, the 32 bit
entries are easier to handle than the odd sized (not a
native CPU word size) 12 bit which can also cross a sector
boundary for added complications. Of course, a full blown
FAT32 driver is expected to process the entries as the
actual 28 bit that it is and maintain the top 4 (reserved)
bits. It's way past the need to be concerned about the
mature FAT32 file system anymore (and even if the bits are
used - say by a file utility) the hobbyist system can safely
ignore them. Of course, handling them correctly is only a
minor thing anyway. Some other small nit picks that would
make the drivers different such as having the directory
entry for the file start cluster in two parts in two
different places is also easily ignored (and just as easily
handled) since the size of the Virtual Partition - even when
8MB would have a max cluster number of only 16K which easily
fits in the original 16 bit entry anyway.


Mike Gonta
look and see - many look but few see

http://mikegonta.com
http://tawk.to/mikegonta

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Thread

The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-03-31 17:51 -0400
  Re: The Virtual Partition - say goodbye to FAT12 Robert Wessel <robertwessel2@yahoo.com> - 2016-03-31 20:48 -0500
    Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-01 06:50 -0400
      Re: The Virtual Partition - say goodbye to FAT12 Robert Wessel <robertwessel2@yahoo.com> - 2016-04-01 11:06 -0500
        Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-01 13:45 -0400
          Re: The Virtual Partition - say goodbye to FAT12 Robert Wessel <robertwessel2@yahoo.com> - 2016-04-01 17:06 -0500
            Re: The Virtual Partition - say goodbye to FAT12 James Harris <james.harris.1@gmail.com> - 2016-04-01 23:16 +0100
              Re: The Virtual Partition - say goodbye to FAT12 Robert Wessel <robertwessel2@yahoo.com> - 2016-04-01 17:29 -0500
                Re: The Virtual Partition - say goodbye to FAT12 Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-04-01 20:24 -0400
                Re: The Virtual Partition - say goodbye to FAT12 Robert Wessel <robertwessel2@yahoo.com> - 2016-04-02 00:10 -0500
                Re: The Virtual Partition - say goodbye to FAT12 Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-04-02 12:03 -0400
                Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 20:19 -0400
                Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 20:08 -0400
                Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 20:02 -0400
                Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 19:55 -0400
              Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 19:30 -0400
            Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 18:55 -0400
              Re: The Virtual Partition - say goodbye to FAT12 Robert Wessel <robertwessel2@yahoo.com> - 2016-04-04 00:40 -0500
  Re: The Virtual Partition - say goodbye to FAT12 "wolfgang kern" <nowhere@never.at> - 2016-04-01 09:20 +0200
    Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-01 07:01 -0400
      Re: The Virtual Partition - say goodbye to FAT12 "wolfgang kern" <nowhere@never.at> - 2016-04-04 10:42 +0200
        Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-05 15:58 -0400
          Re: The Virtual Partition - say goodbye to FAT12 "wolfgang kern" <nowhere@never.at> - 2016-04-05 22:19 +0200
            Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-05 18:24 -0400
  Re: The Virtual Partition - say goodbye to FAT12 James Harris <james.harris.1@gmail.com> - 2016-04-01 09:55 +0100
    Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-01 07:11 -0400
  Re: The Virtual Partition - say goodbye to FAT12 Rod Pemberton <NoHaveNotOne@bcczxcfre.cmm> - 2016-04-01 20:24 -0400
    Re: The Virtual Partition - say goodbye to FAT12 "Mike Gonta" <mikegonta@gmail.com> - 2016-04-02 21:30 -0400

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