1.\" $OpenBSD: fdc.4,v 1.16 2016/09/01 12:24:56 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: September 1 2016 $ 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 "fdc* at sbus? " Pq sparc64 43.\" .Cd "fdc* at ebus? " Pq sparc64 44.Cd "fd* at fdc? flags 0x00" 45.Sh DESCRIPTION 46The 47.Nm 48driver supports the standard AT floppy disk controllers. 49These include standard IDE, MFM, RLL, 50EIDE, ESDI and SCSI controllers with floppy attachment, 51commonly encountered on many isa bus machines, 52as well as the on-board floppy controller found on most 53UltraSPARC workstations. 54.Pp 55The standard names of a floppy drive will take the form 56.Pa /dev/fd{0,1,2,3}{,B,C,D,E,F,G,H}[a-p] . 57.Pp 58The first component of this path is the unit number, permitting 59a total of 4 floppy drives. 60The next component is missing for the default geometry (it 61would be A, but it is omitted for simplicity) and B-H for the 62other 7 geometry types the floppy driver supports. 63The last component of the path is the 16 partitions that a floppy 64disk can support. 65.Pp 66The additional geometry types are as follows: 67.Pp 68.Bl -tag -width xxxxxx -offset indent -compact 69.It `B' 1.44MB 70.It `C' 1.2MB 71.It `D' 360KB/AT (360KB disk in a 1.2 MB drive) 72.It `E' 360KB/PC (360KB drive) 73.It `F' 720KB 74.It `G' 720KB/x (720KB in a 1.2 MB drive) 75.It `H' 360KB/x (360KB in a 720KB drive) 76.El 77.Pp 78The default geometry is the format specified in the BIOS, and 79is typically the largest supported format. 80.Pp 81Some isa floppy controllers do not respond correctly to probes, and 82the configuration file 83.Cm flags 84field can be used to specify a particular drive type, overriding the 85probed type. 86If the 0x10 bit is on, the low order three bits of the 87.Cm flags 88field encode the drive type, as follows: 89.Pp 90.Bl -tag -width 2.88MB -offset indent -compact 91.It 1 2.88MB 92.It 2 1.44MB 93.It 3 1.2MB 94.It 4 720K 95.It 5 360K 96.It 6 1.2 MB Japanese format 97.El 98.Pp 99If the 0x20 bit is on, the drive will be attached even 100if it was not found by the probe routine. 101These flags are ignored on 102.Nm 103controllers not connected to an 104.Xr isa 4 105bus. 106.Sh SEE ALSO 107.Xr eject 1 , 108.Xr fdformat 1 , 109.Xr ebus 4 , 110.Xr intro 4 , 111.Xr isa 4 , 112.Xr sbus 4 113.Sh BUGS 114The 115.Nm 116driver can interfere with other 117.Xr isa 4 118controllers, namely some WD/SMC 119network controllers fail to work when the probing mechanism 120in the 121.Nm 122driver probes for a missing second floppy drive. 123In this case you should try recompiling the kernel 124replacing the relevant line with 125.Cd "fd0 at fdc?" . 126