1.\" Copyright (C) 1993, 1994, 1995, 2001 by Joerg Wunsch, Dresden 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS 14.\" OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 15.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 16.\" DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, 17.\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 18.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 19.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 21.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 22.\" IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 23.\" POSSIBILITY OF SUCH DAMAGE. 24.\" 25.Dd November 16, 2025 26.Dt FDFORMAT 8 27.Os 28.Sh NAME 29.Nm fdformat 30.Nd format floppy disks 31.Sh SYNOPSIS 32.Nm 33.Op Fl F Ar fill 34.Op Fl f Ar fmt 35.Op Fl s Ar fmtstr 36.Op Fl nqvy 37.Ar device 38.Sh DEPRECATION NOTICE 39.Nm 40is deprecated and may not be present in 41.Fx 16.0 42and later. 43.Sh DESCRIPTION 44The 45.Nm 46utility formats a floppy disk at 47.Ar device , 48where 49.Ar device 50may either be given as a full path 51name of a device node for a floppy disk drive 52(e.g.,\& 53.Pa /dev/fd0 ) , 54or using an abbreviated name that will be looked up 55under 56.Pa /dev 57(e.g.,\& 58.Dq Li fd0 ) . 59.Pp 60The options are as follows: 61.Bl -tag -width ".Fl s Ar fmtstr" 62.It Fl F Ar fill 63Use 64.Ar fill 65as the fill byte for newly formatted sectors. 66The 67.Ar fill 68argument 69must be a number in the range 0 through 255 using common C 70language notation. 71The default value is 72.Dq Li 0xf6 . 73.It Fl f Ar fmt 74Specify the density settings for a 75.Ar fmt 76kilobyte format, as described in 77.Xr fdcontrol 8 . 78.It Fl s Ar fmtstr 79Specify the density settings using explicit parameters, as 80described in 81.Xr fdcontrol 8 . 82.It Fl n 83Do not verify floppy after formatting. 84.It Fl q 85Suppress any normal output from the command, and do not ask the 86user for a confirmation whether to format the floppy disk at 87.Ar device . 88.It Fl v 89Do not format, verify only. 90.It Fl y 91Do not ask for confirmation whether to format the floppy disk but 92still report formatting status. 93.El 94.Pp 95For non-autoselecting subdevices, neither 96.Fl f Ar fmt 97nor 98.Fl s Ar fmtstr 99may be specified, since the preconfigured media density settings 100from the kernel driver will always be used. 101However, if 102.Ar device 103is a device with automatic media density selection (see 104.Xr fdc 4 ) , 105both methods can be used to override the density settings for the 106newly formatted medium (without permanently changing the density 107settings of 108.Ar device ) . 109.Pp 110If the 111.Fl q 112flag has not been specified, the user is asked for a confirmation 113of the intended formatting process. 114In order to continue, an answer 115of 116.Ql y 117must be given. 118.Pp 119Note that 120.Nm 121does only perform low-level formatting. 122In order to create 123a file system on the medium, see the commands 124.Xr newfs 8 125for a 126.Tn UFS 127file system, or 128.Xr newfs_msdos 8 129for an 130.Tn MS-DOS 131(FAT) 132file system. 133.Sh EXIT STATUS 134An exit status of 0 is returned upon successful operation. 135Exit status 1361 is returned on any errors during floppy formatting, and an exit status 137of 2 reflects invalid arguments given to the program (along with an 138appropriate information written to diagnostic output). 139.Sh EXAMPLES 140To format a new double-sided, high-density (HD) 1.44 MB disk 141inserted in the first floppy disk drive, issue: 142.Pp 143.Dl "/usr/sbin/fdformat -f 1440 /dev/fd0" 144.Pp 145After low-level formatting the disk with 146.Nm , 147create a disk label so that the system can determine the size and 148geometry of the disk. 149The supported geometry values are listed in 150.Pa /etc/disktab , 151and we will use 152.Va fd1440 153for this example. 154To write the disk label, use 155.Xr bsdlabel 8 : 156.Pp 157.Dl "/sbin/bsdlabel -B -w /dev/fd0 fd1440" 158.Pp 159The floppy is now ready to be high-level formatted with a file system. 160To format the floppy disk with FAT, issue: 161.Pp 162.Dl "/sbin/newfs_msdos /dev/fd0" 163.Sh DIAGNOSTICS 164Unless 165.Fl q 166has been specified, a single letter is printed to standard output 167to inform the user about the progress of work. 168First, an 169.Ql F 170is printed when the track is being formatted, then a 171.Ql V 172while it is being verified, and if an error has been detected, it 173will finally change to 174.Ql E . 175Detailed status information (cylinder, head and sector number, and the 176exact cause of the error) will be printed for up to 10 errors after the 177entire formatting process has completed. 178.Sh SEE ALSO 179.Xr fdc 4 , 180.Xr bsdlabel 8 , 181.Xr fdcontrol 8 , 182.Xr newfs 8 , 183.Xr newfs_msdos 8 184.Sh HISTORY 185The 186.Nm 187utility 188has been developed for 189.Bx 386 0.1 190and upgraded to the new 191.Xr fdc 4 192floppy disk driver. 193It later became part of the 194.Fx 1.1 195system. 196Starting with 197.Fx 5.0 , 198it uses the unified density specifications as described in 199.Xr fdcontrol 8 . 200.Sh AUTHORS 201.An -nosplit 202The program has been contributed by 203.An J\(:org Wunsch , 204Dresden, with changes by 205.An Serge Vakulenko 206and 207.An Andrey A. Chernov , 208Moscow. 209