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(fdutils.info)geometry list

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The geometry list
=================

   The floppy driver contains a builtin list of 32 formats.  This list
is used for two purposes:
   * It says which geometry is used for the _fixed format_ devices.

   * It is used for _autodetection_

   The following formats (geometries) are known:

*format_nr*
     *Format*

0
     autodetect

1
     360KB, 5.25" DD drive

2
     1200KB, 5.25" HD drive

3
     360KB, 3.5" DD drive

4
     720KB, 3.5" DD drive

5
     360KB, 5.25" DD disk in HD drive

6
     720KB, 5.25" DD disk in HD drive

7
     1440KB, 3.5" HD drive

8
     2880KB, 3.5" ED drive

9
     3120KB, 3.5" ED drive

10
     1440KB, 5.25" HD drive

11
     1680KB, 3.5" HD drive

12
     410KB, 5.25" DD disk in HD drive

13
     820KB, 3.5" DD drive

14
     1476KB, 5.25" HD drive

15
     1722KB, 3.5" HD drive

16
     420KB, 5.25" DD disk in HD drive

17
     830KB, 3.5" DD drive

18
     1494KB, 5.25" HD drive

19
     1743KB, 3.5" HD drive

20
     880KB, 5.25" DD drive

21
     1040KB, 3.5" DD drive

22
     1120KB, 3.5" DD drive

23
     1600KB, 5.25" HD drive

24
     1760KB, 3.5" HD drive

25
     1920KB, 3.5" HD drive

26
     3200KB, 3.5" ED drive

27
     3520KB, 3.5" ED drive

28
     3840KB, 3.5" ED drive

29
     1840KB, 3.5" HD drive

30
     800KB, 3.5" DD drive

31
     1600KB, 3.5" HD drive

   This table lists first the format_nr (0-31) used to compute the minor
number, then the capacity of the format (360KB - 3200KB), and then the
type of the drive in which this format is used.

   The formats 0..8 are the standard PC formats.  The remaining formats
are extended capacity formats. Some of them have been taken from Heiko
Schroeder's fdpatches (after correcting some minor bugs).  Others have
been added by David Niemi and me (Alain Knaff).  Formats 9, 12, 13, 16,
17, 30 and 31 are non-interleaved formats with normal sized sectors, and
have the highest capacity that can be achieved without resorting to
interleaving or bigger sectors (Note: More sectors).  Formats 10, 11,
14, 15, 18, 19 use interleaving interleaving to achieve a higher
capacity (Note: Interleave).  Formats 20 and 22 to 29 use bigger
sectors than usual (Note: Larger sectors and Note: Mixed size
sectors).

   In addition to these techniques, formats 13-19 use more cylinders
than usual (Note: More cylinders).  *USE THESE FORMATS (13-19) ONLY IF
YOUR DRIVE SUPPORTS THE NECESSARY NUMBER OF TRACKS*