Add a manual page for the Amiga custom chip floppy disk controller device,

mostly geared towards explaining the pseudo-partition encodings; with input
from Ignatios Souvatzis.

share/man/man4/man4.amiga/fdc.4

@@ -0,0 +1,86 @@
+.\"	$NetBSD: fdc.4,v 1.1 1998/07/05 19:58:30 kleink Exp $
+.\"
+.\" Copyright (c) 1998 The NetBSD Foundation, Inc.
+.\" All rights reserved.
+.\"
+.\" This code is derived from software contributed to The NetBSD Foundation
+.\" by Klaus J. Klein.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"        This product includes software developed by the NetBSD
+.\"        Foundation, Inc. and its contributors.
+.\" 4. Neither the name of The NetBSD Foundation nor the names of its
+.\"    contributors may be used to endorse or promote products derived
+.\"    from this software without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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+.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+.\" POSSIBILITY OF SUCH DAMAGE.
+.\"
+.Dd February 28, 1998
+.Dt FDC 4 amiga
+.Os NetBSD 1.0
+.Sh NAME
+.Nm fdc
+.Nd Amiga custom chip floppy disk controller device
+.Sh SYNOPSIS
+.Cd "fdc0 at mainbus0"
+.Cd "fd* at fdc? unit ?"
+.Sh DESCRIPTION
+The
+.Nm
+device driver provides support for the mainboard floppy disk controller and
+floppy disk drives on Amiga systems.
+.Pp
+The driver supports the following floppy diskette formats by using
+particular partitions:
+.Bl -tag -width -offset indent -compact
+.It "880KB " "3.5-inch " 11 sectors/track (``Amiga'') (a)
+.It "1.76MB" "3.5-inch " 22 sectors/track (``Amiga'') (a)
+.It "880KB " "5.25-inch" 11 sectors/track (``Amiga'') (a)
+.It "720KB " "3.5-inch "  9 sectors/track (``MS-DOS'') (b)
+.It "1.44MB" "3.5-inch " 18 sectors/track (``MS-DOS'') (b)
+.It "720KB " "5.25-inch"  9 sectors/track (``MS-DOS'') (b)
+.El
+On systems equipped with floppy disk drives capable of using high-density
+floppy diskettes,
+the driver automatically detects whether the inserted floppy diskette is
+either a double-density or a high-density medium.
+.Sh DIAGNOSTICS
+.Bl -diag
+.It "fdc: unable to allocate dma buffer"
+The driver found the controller, but was unable to allocate the
+amount of chip memory required for its DMA buffers.
+.El
+.Sh BUGS
+In order to detect a floppy disk drive's capability of using high-density
+media, a high-density diskette has to be inserted for the duration of the
+autoconfiguration phase of the drive.
+.Pp
+The
+.Nm
+driver supports neither the
+.Xr fdformat 1
+facility nor the
+.Pa Aq sys/fdio.h
+interface.
+.Sh SEE ALSO
+.Xr fdformat 1 ,
+.Xr autoconf 4