| '\" t |
| .\" Copyright (c) 1993 Michael Haardt (michael@cantor.informatik.rwth-aachen.de) |
| .\" and 1994,1995 Alain Knaff (Alain.Knaff@imag.fr) |
| .\" |
| .\" SPDX-License-Identifier: GPL-2.0-or-later |
| .\" |
| .\" Modified, Sun Feb 26 15:00:02 1995, faith@cs.unc.edu |
| .\" |
| .TH fd 4 (date) "Linux man-pages (unreleased)" |
| .SH NAME |
| fd \- floppy disk device |
| .SH CONFIGURATION |
| Floppy drives are block devices with major number 2. |
| Typically they |
| are owned by |
| root:floppy |
| (i.e., user root, group floppy) and have |
| either mode 0660 (access checking via group membership) or mode 0666 |
| (everybody has access). |
| The minor |
| numbers encode the device type, drive number, and controller number. |
| For each device type (that is, combination of density and track count) |
| there is a base minor number. |
| To this base number, add the drive's |
| number on its controller and 128 if the drive is on the secondary |
| controller. |
| In the following device tables, \fIn\fP represents the |
| drive number. |
| .P |
| \fBWarning: if you use formats with more tracks |
| than supported by your drive, you may cause it mechanical damage.\fP |
| Trying once if more tracks than the usual 40/80 are supported should not |
| damage it, but no warranty is given for that. |
| If you are not sure, don't create device |
| entries for those formats, so as to prevent their usage. |
| .P |
| Drive-independent device files which automatically detect the media |
| format and capacity: |
| .TS |
| l c |
| l c. |
| Name Base |
| minor # |
| _ |
| \fBfd\fP\fIn\fP 0 |
| .TE |
| .P |
| 5.25 inch double-density device files: |
| .TS |
| lw(1i) l l l l c |
| lw(1i) c c c c c. |
| Name Capacity Cyl. Sect. Heads Base |
| KiB minor # |
| _ |
| \fBfd\fP\fIn\fP\fBd360\fP 360 40 9 2 4 |
| .TE |
| .P |
| 5.25 inch high-density device files: |
| .TS |
| lw(1i) l l l l c |
| lw(1i) c c c c c. |
| Name Capacity Cyl. Sect. Heads Base |
| KiB minor # |
| _ |
| \fBfd\fP\fIn\fP\fBh360\fP 360 40 9 2 20 |
| \fBfd\fP\fIn\fP\fBh410\fP 410 41 10 2 48 |
| \fBfd\fP\fIn\fP\fBh420\fP 420 42 10 2 64 |
| \fBfd\fP\fIn\fP\fBh720\fP 720 80 9 2 24 |
| \fBfd\fP\fIn\fP\fBh880\fP 880 80 11 2 80 |
| \fBfd\fP\fIn\fP\fBh1200\fP 1200 80 15 2 8 |
| \fBfd\fP\fIn\fP\fBh1440\fP 1440 80 18 2 40 |
| \fBfd\fP\fIn\fP\fBh1476\fP 1476 82 18 2 56 |
| \fBfd\fP\fIn\fP\fBh1494\fP 1494 83 18 2 72 |
| \fBfd\fP\fIn\fP\fBh1600\fP 1600 80 20 2 92 |
| .TE |
| .P |
| 3.5 inch double-density device files: |
| .TS |
| lw(1i) l l l l c |
| lw(1i) c c c c c. |
| Name Capacity Cyl. Sect. Heads Base |
| KiB minor # |
| _ |
| \fBfd\fP\fIn\fP\fBu360\fP 360 80 9 1 12 |
| \fBfd\fP\fIn\fP\fBu720\fP 720 80 9 2 16 |
| \fBfd\fP\fIn\fP\fBu800\fP 800 80 10 2 120 |
| \fBfd\fP\fIn\fP\fBu1040\fP 1040 80 13 2 84 |
| \fBfd\fP\fIn\fP\fBu1120\fP 1120 80 14 2 88 |
| .TE |
| .P |
| 3.5 inch high-density device files: |
| .TS |
| lw(1i) l l l l c |
| lw(1i) c c c c c. |
| Name Capacity Cyl. Sect. Heads Base |
| KiB minor # |
| _ |
| \fBfd\fP\fIn\fP\fBu360\fP 360 40 9 2 12 |
| \fBfd\fP\fIn\fP\fBu720\fP 720 80 9 2 16 |
| \fBfd\fP\fIn\fP\fBu820\fP 820 82 10 2 52 |
| \fBfd\fP\fIn\fP\fBu830\fP 830 83 10 2 68 |
| \fBfd\fP\fIn\fP\fBu1440\fP 1440 80 18 2 28 |
| \fBfd\fP\fIn\fP\fBu1600\fP 1600 80 20 2 124 |
| \fBfd\fP\fIn\fP\fBu1680\fP 1680 80 21 2 44 |
| \fBfd\fP\fIn\fP\fBu1722\fP 1722 82 21 2 60 |
| \fBfd\fP\fIn\fP\fBu1743\fP 1743 83 21 2 76 |
| \fBfd\fP\fIn\fP\fBu1760\fP 1760 80 22 2 96 |
| \fBfd\fP\fIn\fP\fBu1840\fP 1840 80 23 2 116 |
| \fBfd\fP\fIn\fP\fBu1920\fP 1920 80 24 2 100 |
| .TE |
| .P |
| 3.5 inch extra-density device files: |
| .TS |
| lw(1i) l l l l c |
| lw(1i) c c c c c. |
| Name Capacity Cyl. Sect. Heads Base |
| KiB minor # |
| _ |
| \fBfd\fP\fIn\fP\fBu2880\fP 2880 80 36 2 32 |
| \fBfd\fP\fIn\fP\fBCompaQ\fP 2880 80 36 2 36 |
| \fBfd\fP\fIn\fP\fBu3200\fP 3200 80 40 2 104 |
| \fBfd\fP\fIn\fP\fBu3520\fP 3520 80 44 2 108 |
| \fBfd\fP\fIn\fP\fBu3840\fP 3840 80 48 2 112 |
| .TE |
| .SH DESCRIPTION |
| \fBfd\fP special files access the floppy disk drives in raw mode. |
| The following |
| .BR ioctl (2) |
| calls are supported by \fBfd\fP devices: |
| .TP |
| .B FDCLRPRM |
| clears the media information of a drive (geometry of disk in drive). |
| .TP |
| .B FDSETPRM |
| sets the media information of a drive. |
| The media information will be |
| lost when the media is changed. |
| .TP |
| .B FDDEFPRM |
| sets the media information of a drive (geometry of disk in drive). |
| The media information will not be lost when the media is changed. |
| This will disable autodetection. |
| In order to reenable autodetection, you |
| have to issue an \fBFDCLRPRM\fP. |
| .TP |
| .B FDGETDRVTYP |
| returns the type of a drive (name parameter). |
| For formats which work |
| in several drive types, \fBFDGETDRVTYP\fP returns a name which is |
| appropriate for the oldest drive type which supports this format. |
| .TP |
| .B FDFLUSH |
| invalidates the buffer cache for the given drive. |
| .TP |
| .B FDSETMAXERRS |
| sets the error thresholds for reporting errors, aborting the operation, |
| recalibrating, resetting, and reading sector by sector. |
| .TP |
| .B FDSETMAXERRS |
| gets the current error thresholds. |
| .TP |
| .B FDGETDRVTYP |
| gets the internal name of the drive. |
| .TP |
| .B FDWERRORCLR |
| clears the write error statistics. |
| .TP |
| .B FDWERRORGET |
| reads the write error statistics. |
| These include the total number of |
| write errors, the location and disk of the first write error, and the |
| location and disk of the last write error. |
| Disks are identified by a |
| generation number which is incremented at (almost) each disk change. |
| .TP |
| .B FDTWADDLE |
| Switch the drive motor off for a few microseconds. |
| This might be |
| needed in order to access a disk whose sectors are too close together. |
| .TP |
| .B FDSETDRVPRM |
| sets various drive parameters. |
| .TP |
| .B FDGETDRVPRM |
| reads these parameters back. |
| .TP |
| .B FDGETDRVSTAT |
| gets the cached drive state (disk changed, write protected et al.) |
| .TP |
| .B FDPOLLDRVSTAT |
| polls the drive and return its state. |
| .TP |
| .B FDGETFDCSTAT |
| gets the floppy controller state. |
| .TP |
| .B FDRESET |
| resets the floppy controller under certain conditions. |
| .TP |
| .B FDRAWCMD |
| sends a raw command to the floppy controller. |
| .P |
| For more precise information, consult also the \fI<linux/fd.h>\fP and |
| \fI<linux/fdreg.h>\fP include files, as well as the |
| .BR floppycontrol (1) |
| manual page. |
| .SH FILES |
| .I /dev/fd* |
| .SH NOTES |
| The various formats permit reading and writing many types of disks. |
| However, if a floppy is formatted with an inter-sector gap that is too small, |
| performance may drop, |
| to the point of needing a few seconds to access an entire track. |
| To prevent this, use interleaved formats. |
| .P |
| It is not possible to |
| read floppies which are formatted using GCR (group code recording), |
| which is used by Apple II and Macintosh computers (800k disks). |
| .P |
| Reading floppies which are hard sectored (one hole per sector, with |
| the index hole being a little skewed) is not supported. |
| This used to be common with older 8-inch floppies. |
| .\" .SH AUTHORS |
| .\" Alain Knaff (Alain.Knaff@imag.fr), David Niemi |
| .\" (niemidc@clark.net), Bill Broadhurst (bbroad@netcom.com). |
| .SH SEE ALSO |
| .BR chown (1), |
| .BR floppycontrol (1), |
| .BR getfdprm (1), |
| .BR mknod (1), |
| .BR superformat (1), |
| .BR mount (8), |
| .BR setfdprm (8) |
