1.\" 2.\" Copyright (c) 1994 Wilko Bulte 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. The name of the author may not be used to endorse or promote products 14.\" derived from this software without specific prior written permission 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26.\" 27.\" $FreeBSD: src/share/man/man4/fdc.4,v 1.20.2.5 2001/10/01 13:07:23 dd Exp $ 28.\" $DragonFly: src/share/man/man4/fdc.4,v 1.2 2003/06/17 04:36:59 dillon Exp $ 29.\" 30.Dd August 31, 1994 31.Dt FDC 4 32.Os 33.Sh NAME 34.Nm fdc 35.Nd PC architecture floppy disk controller driver 36.Sh SYNOPSIS 37.Cd "device fdc0 at isa? port IO_FD1 flags 0x1 irq 6 drq 2" 38.Cd device fd0 at fdc0 drive 0 39.Cd device fd1 at fdc0 drive 1 40.Sh DESCRIPTION 41This driver provides access to floppy disk drives and QIC40/80 tapedrives. 42In /dev for each floppy device a number of minor devices are present. 43The 44/dev/fd* devices with trailing alphabetic characters are used to indicate 45.Sq partitions 46on the floppy disk. 47The /dev/fd*.<number> are devices that 48indicate the size of the floppy disk (so: 720kB, 1440kB etc). The latter 49are used for formatting disks using fdformat or for accessing different 50density disks in multidensity drive. 51Example: 720kB disk in a 1.44Mb drive. 52.Pp 53Normally, the driver will ask the system's CMOS memory to obtain the 54floppy drive configuration. Some machines do not store any form of a 55configuration value in their CMOS. Use the flags value 56.Ql 0x1 57to pretend a 1.44 MB floppy drive as the first unit, without asking the 58CMOS for it. 59.Pp 60The flags value 61.Ql 0x2 62is reserved for PCMCIA floppy use, and should never be set in a 63configuration file directly. It is internally handled in the driver 64if the compilation option 65.Dv FDC_YE 66is set, and defers device probing. 67.Pp 68Normally, the device driver detects FDC chipsets that have an internal 69FIFO, and enables the FIFO on them. There is a slight chance that this 70feature is actually misdetected (seen on an IBM Thinkpad 755c), so it 71can be turned off using flags 72.Ql 0x4 . 73.Sh FILES 74.Bl -tag -width Pa -compact 75.It Pa /dev/fd* 76floppy disk device nodes 77.It Pa /dev/fd*. Ns Ar "<size in kB>" 78floppy disk device nodes where the trailing number indicates the floppy 79capacity 80.It Pa /sys/i386/conf/GENERIC 81sample generic kernel config file 82.It Pa /sys/isa/fd.c 83floppy driver source 84.El 85.Sh SEE ALSO 86.Xr fdformat 1 , 87.Xr disktab 5 88