2 .\" Copyright (c) 1993 Michael Haardt (michael@cantor.informatik.rwth-aachen.de)
3 .\" and 1994,1995 Alain Knaff (Alain.Knaff@imag.fr)
5 .\" This is free documentation; you can redistribute it and/or
6 .\" modify it under the terms of the GNU General Public License as
7 .\" published by the Free Software Foundation; either version 2 of
8 .\" the License, or (at your option) any later version.
10 .\" The GNU General Public License's references to "object code"
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12 .\" document formatting or typesetting system, including
13 .\" intermediate and printed output.
15 .\" This manual is distributed in the hope that it will be useful,
16 .\" but WITHOUT ANY WARRANTY; without even the implied warranty of
17 .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 .\" GNU General Public License for more details.
20 .\" You should have received a copy of the GNU General Public
21 .\" License along with this manual; if not, write to the Free
22 .\" Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111,
25 .\" Modified, Sun Feb 26 15:00:02 1995, faith@cs.unc.edu
27 .TH FD 4 1995-01-29 "Linux" "Linux Programmer's Manual"
29 fd \- floppy disk device
31 Floppy drives are block devices with major number 2.
33 are owned by root.floppy (i.e., user root, group floppy) and have
34 either mode 0660 (access checking via group membership) or mode 0666
35 (everybody has access).
37 numbers encode the device type, drive number, and controller number.
38 For each device type (that is, combination of density and track count)
39 there is a base minor number.
40 To this base number, add the drive's
41 number on its controller and 128 if the drive is on the secondary
43 In the following device tables, \fIn\fP represents the
46 \fBWarning: If you use formats with more tracks
47 than supported by your drive, you may cause it mechanical damage.\fP
48 Trying once if more tracks than the usual 40/80 are supported should not
49 damage it, but no warranty is given for that.
51 entries for those formats to prevent their usage if you are not sure.
53 Drive independent device files which automatically detect the media
62 5.25 inch double density device files:
65 Name Capac. Cyl. Sect. Heads Base minor #
67 \fBfd\fP\fIn\fP\fBd360\fP 360K 40 9 2 4
70 5.25 inch high density device files:
73 Name Capac. Cyl. Sect. Heads Base minor #
75 \fBfd\fP\fIn\fP\fBh360\fP 360K 40 9 2 20
76 \fBfd\fP\fIn\fP\fBh410\fP 410K 41 10 2 48
77 \fBfd\fP\fIn\fP\fBh420\fP 420K 42 10 2 64
78 \fBfd\fP\fIn\fP\fBh720\fP 720K 80 9 2 24
79 \fBfd\fP\fIn\fP\fBh880\fP 880K 80 11 2 80
80 \fBfd\fP\fIn\fP\fBh1200\fP 1200K 80 15 2 8
81 \fBfd\fP\fIn\fP\fBh1440\fP 1440K 80 18 2 40
82 \fBfd\fP\fIn\fP\fBh1476\fP 1476K 82 18 2 56
83 \fBfd\fP\fIn\fP\fBh1494\fP 1494K 83 18 2 72
84 \fBfd\fP\fIn\fP\fBh1600\fP 1600K 80 20 2 92
87 3.5 inch double density device files:
90 Name Capac. Cyl. Sect. Heads Base minor #
92 \fBfd\fP\fIn\fP\fBD360\fP 360K 80 9 1 12
93 \fBfd\fP\fIn\fP\fBD720\fP 720K 80 9 2 16
94 \fBfd\fP\fIn\fP\fBD800\fP 800K 80 10 2 120
95 \fBfd\fP\fIn\fP\fBD1040\fP 1040K 80 13 2 84
96 \fBfd\fP\fIn\fP\fBD1120\fP 1120K 80 14 2 88
99 3.5 inch high density device files:
102 Name Capac. Cyl. Sect. Heads Base minor #
104 \fBfd\fP\fIn\fP\fBH360\fP 360K 40 9 2 12
105 \fBfd\fP\fIn\fP\fBH720\fP 720K 80 9 2 16
106 \fBfd\fP\fIn\fP\fBH820\fP 820K 82 10 2 52
107 \fBfd\fP\fIn\fP\fBH830\fP 830K 83 10 2 68
108 \fBfd\fP\fIn\fP\fBH1440\fP 1440K 80 18 2 28
109 \fBfd\fP\fIn\fP\fBH1600\fP 1600K 80 20 2 124
110 \fBfd\fP\fIn\fP\fBH1680\fP 1680K 80 21 2 44
111 \fBfd\fP\fIn\fP\fBH1722\fP 1722K 82 21 2 60
112 \fBfd\fP\fIn\fP\fBH1743\fP 1743K 83 21 2 76
113 \fBfd\fP\fIn\fP\fBH1760\fP 1760K 80 22 2 96
114 \fBfd\fP\fIn\fP\fBH1840\fP 1840K 80 23 2 116
115 \fBfd\fP\fIn\fP\fBH1920\fP 1920K 80 24 2 100
118 3.5 inch extra density device files:
121 Name Capac. Cyl. Sect. Heads Base minor #
123 \fBfd\fP\fIn\fP\fBE2880\fP 2880K 80 36 2 32
124 \fBfd\fP\fIn\fP\fBCompaQ\fP 2880K 80 36 2 36
125 \fBfd\fP\fIn\fP\fBE3200\fP 3200K 80 40 2 104
126 \fBfd\fP\fIn\fP\fBE3520\fP 3520K 80 44 2 108
127 \fBfd\fP\fIn\fP\fBE3840\fP 3840K 80 48 2 112
130 \fBfd\fP special files access the floppy disk drives in raw mode.
133 calls are supported by \fBfd\fP devices:
135 clears the media information of a drive (geometry of disk in drive).
137 sets the media information of a drive.
138 The media information will be
139 lost when the media is changed.
141 sets the media information of a drive (geometry of disk in drive).
142 The media information will not be lost when the media is changed.
143 This will disable autodetection.
144 In order to reenable autodetection, you
145 have to issue an \fBFDCLRPRM\fP.
146 .IP \fBFDGETDRVTYP\fP
147 returns the type of a drive (name parameter).
148 For formats which work
149 in several drive types, \fBFDGETDRVTYP\fP returns a name which is
150 appropriate for the oldest drive type which supports this format.
152 invalidates the buffer cache for the given drive.
153 .IP \fBFDSETMAXERRS\fP
154 sets the error thresholds for reporting errors, aborting the operation,
155 recalibrating, resetting, and reading sector by sector.
156 .IP \fBFDSETMAXERRS\fP
157 gets the current error thresholds.
158 .IP \fBFDGETDRVTYP\fP
159 gets the internal name of the drive.
160 .IP \fBFDWERRORCLR\fP
161 clears the write error statistics.
162 .IP \fBFDWERRORGET\fP
163 reads the write error statistics.
164 These include the total number of
165 write errors, the location and disk of the first write error, and the
166 location and disk of the last write error.
167 Disks are identified by a
168 generation number which is incremented at (almost) each disk change.
170 Switch the drive motor off for a few microseconds.
172 needed in order to access a disk whose sectors are too close together.
173 .IP \fBFDSETDRVPRM\fP
174 sets various drive parameters.
175 .IP \fBFDGETDRVPRM\fP
176 reads these parameters back.
177 .IP \fBFDGETDRVSTAT\fP
178 gets the cached drive state (disk changed, write protected et al.)
179 .IP \fBFDPOLLDRVSTAT\fP
180 polls the drive and return its state.
181 .IP \fBFDGETFDCSTAT\fP
182 gets the floppy controller state.
184 resets the floppy controller under certain conditions.
186 sends a raw command to the floppy controller.
188 For more precise information, consult also the \fI<linux/fd.h>\fP and
189 \fI<linux/fdreg.h>\fP include files, as well as the manual page for
194 The various formats allow to read and write many types of disks.
195 However, if a floppy is formatted with a too small inter sector gap,
196 performance may drop, up to needing a few seconds to access an entire
198 To prevent this, use interleaved formats.
199 It is not possible to
200 read floppies which are formatted using GCR (group code recording),
201 which is used by Apple II and Macintosh computers (800k disks).
202 Reading floppies which are hard sectored (one hole per sector, with
203 the index hole being a little skewed) is not supported.
204 This used to be common with older 8 inch floppies.
206 .\" Alain Knaff (Alain.Knaff@imag.fr), David Niemi
207 .\" (niemidc@clark.net), Bill Broadhurst (bbroad@netcom.com).
210 .BR floppycontrol (1),