1.\" $OpenBSD: fdc.4,v 1.15 2007/05/31 19:19:50 jmc Exp $ 2.\" $NetBSD: fdc.4,v 1.6 1996/03/22 01:55:14 andrew Exp $ 3.\" 4.\" Copyright (c) 1996 Andrew C. Wheadon 5.\" Copyright (c) 1983, 1991, 1993 6.\" The Regents of the University of California. All rights reserved. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)fdc.4 8.1 (Berkeley) 3/22/96 33.\" 34.Dd $Mdocdate: May 31 2007 $ 35.Dt FDC 4 36.Os 37.Sh NAME 38.Nm fdc 39.Nd NEC765 compatible floppy disk driver 40.Sh SYNOPSIS 41.Cd "fdc0 at isa? port 0x3f0 irq 6 drq 2 " Pq alpha, amd64, i386 42.Cd "fdc0 at mainbus0 " Pq sun4c sparc 43.Cd "fdc0 at obio0 " Pq sun4m sparc 44.Cd "fdc* at sbus? " Pq sparc64 45.\" .Cd "fdc* at ebus? " Pq sparc64 46.Cd "fd* at fdc? flags 0x00" 47.Sh DESCRIPTION 48The 49.Nm 50driver supports the standard AT floppy disk controllers. 51These include standard IDE, MFM, RLL, 52EIDE, ESDI and SCSI controllers with floppy attachment, 53commonly encountered on many isa bus machines, 54as well as the on-board floppy controller found on most 55sparc and UltraSPARC workstations. 56.Pp 57The standard names of a floppy drive will take the form 58.Pa /dev/fd{0,1,2,3}{,B,C,D,E,F,G,H}[a-p] . 59.Pp 60The first component of this path is the unit number, permitting 61a total of 4 floppy drives. 62The next component is missing for the default geometry (it 63would be A, but it is omitted for simplicity) and B-H for the 64other 7 geometry types the floppy driver supports. 65The last component of the path is the 16 partitions that a floppy 66disk can support. 67.Pp 68The additional geometry types are as follows: 69.Pp 70.Bl -tag -width xxxxxx -offset indent -compact 71.It `B' 1.44MB 72.It `C' 1.2MB 73.It `D' 360KB/AT (360KB disk in a 1.2 MB drive) 74.It `E' 360KB/PC (360KB drive) 75.It `F' 720KB 76.It `G' 720KB/x (720KB in a 1.2 MB drive) 77.It `H' 360KB/x (360KB in a 720KB drive) 78.El 79.Pp 80The default geometry is the format specified in the BIOS, and 81is typically the largest supported format. 82.Pp 83Some isa floppy controllers do not respond correctly to probes, and 84the configuration file 85.Cm flags 86field can be used to specify a particular drive type, overriding the 87probed type. 88If the 0x10 bit is on, the low order three bits of the 89.Cm flags 90field encode the drive type, as follows: 91.Pp 92.Bl -tag -width 2.88MB -offset indent -compact 93.It 1 2.88MB 94.It 2 1.44MB 95.It 3 1.2MB 96.It 4 720K 97.It 5 360K 98.It 6 1.2 MB Japanese format 99.El 100.Pp 101If the 0x20 bit is on, the drive will be attached even 102if it was not found by the probe routine. 103These flags are ignored on 104.Nm 105controllers not connected to an 106.Xr isa 4 107bus. 108.Sh SEE ALSO 109.Xr eject 1 , 110.Xr fdformat 1 , 111.Xr ebus 4 , 112.Xr intro 4 , 113.Xr isa 4 , 114.Xr sbus 4 115.Sh BUGS 116The 117.Nm 118driver can interfere with other 119.Xr isa 4 120controllers, namely some WD/SMC 121network controllers fail to work when the probing mechanism 122in the 123.Nm 124driver probes for a missing second floppy drive. 125In this case you should try recompiling the kernel 126replacing the relevant line with 127.Cd "fd0 at fdc?" . 128