fd(7D)								      Devices								    fd(7D)

NAME

       fd, fdc - drivers for floppy disks and floppy disk controllers

SYNOPSIS

   SPARC
       /dev/diskette0

       /dev/rdiskette0

   x86
       /dev/diskette[0-1]

       /dev/rdiskette[0-1]

DESCRIPTION

       The fd and fdc drivers provide the interfaces to floppy disks using the Intel 8272, Intel 82077, NEC 765, or compatible disk controllers on
       x86 based systems.

       The default partitions for the floppy driver are:

       a    All cylinders except the last

       b    Only the last cylinder

       c    Entire diskette

       The fd driver autosenses the density of the diskette.

       When the floppy is first opened the driver looks for a SunOS label in logical block 0 of the diskette. If attempts to read the SunOS  label
       fail, the open will fail. If block 0 is read successfully but a SunOS label is not found, auto-sensed geometry and default partitioning are
       assumed.

       The fd driver supports both block and raw interfaces.

       The block files (/dev/diskette*) access the diskette using the system's normal buffering mechanism and may  be  read  and  written  without
       regard to physical diskette records.

       There  is  also	a  raw (/dev/rdiskette*) interface that provides for direct transmission between the diskette and the user's read or write
       buffer. A single read(2) or write(2) call usually results in one I/O operation; therefore raw  I/O  is  considerably  more  efficient  when
       larger  blocking factors are used. A blocking factor of no less than 8 Kbytes is recommended. See the Notes section, below, for information
       on the number of sectors per track.

   3.5 Diskettes"
       For 3.5" double-sided diskettes, the following densities are supported:

   SPARC
       1.7 Mbyte density    80 cylinders, 21 sectors per track, 1.7 Mbyte capacity

       high density	    80 cylinders, 18 sectors per track, 1.44 Mbyte capacity

       double density	    80 cylinders, 9 sectors per track, 720 Kbyte capacity

   x86
       extended density     80 cylinders, 36 sectors per track, 2.88 Mbyte capacity

       1.7 Mbyte density    80 cylinders, 21 sectors per track, 1.7 Mbyte capacity

       high density	    80 cylinders, 18 sectors per track, 1.44 Mbyte capacity

       double density	    80 cylinders, 9 sectors per track, 760 Kbyte capacity

   5.25 Diskettes"
       For 5.25" double-sided diskettes on x86 platforms, the densities listed below are supported:

   SPARC
       5.25" diskettes are not supported on SPARC platforms.

   x86
       high density	 80 cylinders, 15 sectors per track, 1.2 Mbyte capacity

       double density	 40 cylinders, 9 sectors per track, 360 Kbyte capacity

       double density	 40 cylinders, 8 sectors per track, 320 Kbyte capacity

       quad density	 80 cylinders, 9 sectors per track, 720 Kbyte capacity

       double density	 40 cylinders, 16 sectors per track (256 bytes per sector), 320 Kbyte capacity

       double density	 40 cylinders, 4 sectors per track (1024 bytes per sector), 320 Kbyte capacity

ERRORS

       EBUSY	 During opening, the partition has been opened for exclusive access and another process wants to open the  partition.  Once  open,
		 this  error  is  returned if the floppy disk driver attempted to pass a command to the floppy disk controller when the controller
		 was busy handling another command. In this case, the application should try the operation again.

       EFAULT	 An invalid address was specified in an ioctl command (see fdio(7I)).

       EINVAL	 The number of bytes read or written is not a multiple of the diskette's sector size. This error is also returned when	an  unsup-
		 ported command is specified using the FDIOCMD ioctl command (see fdio(7I)).

       EIO	 During opening, the diskette does not have a label or there is no diskette in the drive. Once open, this error is returned if the
		 requested I/O transfer could not be completed.

       ENOSPC	 An attempt was made to write past the end of the diskette.

       ENOTTY	 The floppy disk driver does not support the requested ioctl functions (see fdio(7I)).

       ENXIO	 The floppy disk device does not exist or the device is not ready.

       EROFS	 The floppy disk device is opened for write access and the diskette in the drive is write protected.

   x86 Only
       ENOSYS	 The floppy disk device does not support the requested ioctl function ( FDEJECT).

X86 CONFIGURATION
       The driver attempts to initialize itself using the information found in the configuration file, /platform/i86pc/kernel/drv/fd.conf.

	 name="fd"  parent="fdc"  unit=0;
	 name="fd"  parent="fdc"  unit=1;

FILES

   SPARC
       /platform/sun4u/kernel/drv/fd

	   driver module

       /usr/include/sys/fdreg.h

	   structs and definitions for Intel 82072 and 82077 controllers

       /usr/include/sys/fdvar.h

	   structs and definitions for floppy drivers

       /dev/diskette

	   device file

       /dev/diskette0

	   device file

       /dev/rdiskette

	   raw device file

       /dev/rdiskette0

	   raw device file

   For ucb Compatibility
       /dev/fd0[a-c]	       block file

       /dev/rfd0[a-c]	       raw file

       /dev/diskette0	       directory containing volume management character device file

       /dev/rdiskette0	       directory containing the volume management raw character device file

       /dev/aliases/floppy0    symbolic link to the entry in /dev/rdiskette0

   x86
       /platform/i86pc/kernel/drv/fd

	   driver module

       /platform/i86pc/kernel/drv/fd.conf

	   configuration file for floppy driver

       /platform/i86pc/kernel/drv/fdc

	   floppy-controller driver module

       /platform/i86pc/kernel/drv/fdc.conf

	   configuration file for the floppy-controller

       /usr/include/sys/fdc.h

	   structs and definitions for x86 floppy devices

       /usr/include/sys/fdmedia.h

	   structs and definitions for x86 floppy media

   x86 First Drive
       /dev/diskette	  device file

       /dev/diskette0	  device file

       /dev/rdiskette	  raw device file

       /dev/rdiskette0	  raw device file

   For ucb Compatibility
       /dev/fd0[a-c]	       block file

       /dev/rfd0[a-c]	       raw file

       /dev/diskette0	       directory containing volume management character device file

       /dev/rdiskette0	       directory containing the volume management raw character device file

       /dev/aliases/floppy0    symbolic link to the entry in /dev/rdiskette0

   x86 Second Drive
       /dev/diskette1	  device file

       /dev/rdiskette1	  raw device file

   For ucb Compatibility
       /dev/fd1[a-c]	       block file

       /dev/rfd1[a-c]	       raw file

       /dev/diskette1	       directory containing volume management character device file

       /dev/rdiskette1	       directory containing the volume management raw character device file

       /dev/aliases/floppy1    symbolic link to the entry in /dev/rdiskette1

SEE ALSO

       fdformat(1), dd(1M), drvconfig(1M), read(2), write(2), driver.conf(4), dkio(7I) fdio(7I)

DIAGNOSTICS

   All Platforms
       fd<n>: <command name> failed (<sr1> <sr2> <sr3>)

	   The <command name> failed after several retries on drive <n>. The three hex values in parenthesis are the contents of  status  register
	   0,  status  register 1, and status register 2 of the Intel 8272, the Intel 82072, and the Intel 82077 Floppy Disk Controller on comple-
	   tion of the command, as documented in the data sheet for that part. This error message is usually followed by  one  of  the	following,
	   interpreting the bits of the status register:

	   fd<n>:    not writable

	   fd<n>:    crc error blk <block number>

		     There was a data error on <block number>.

	   fd<n>:    bad format

	   fd<n>:    timeout

	   fd<n>:    drive not ready

	   fd<n>:    unformatted diskette or no diskette in drive

	   fd<n>:    block <block number> is past the end!

		     (nblk=<total number of blocks>)

		     The operation tried to access a block number that is greater than the total number of blocks.

	   fd<n>:    b_bcount 0x<op_size> not % 0x<sect_size>

		     The size of an operation is not a multiple of the sector size.

	   fd<n>:    overrun/underrun

	   fd<n>:    host bus error. There was a hardware error on a system bus.

   SPARC Only
       Overrun/underrun  errors  occur when accessing a diskette while the system is heavily loaded. Decrease the load on the system and retry the
       diskette access.

NOTES

       3.5" high density diskettes have 18 sectors per track and 5.25" high density diskettes have 15 sectors per track. They can  cross  a  track
       (though	not  a	cylinder)  boundary  without  losing data, so when using dd(1M) or read(2)/write(2) calls to or from the raw diskette, you
       should specify bs=18k or multiples thereof for 3.5" diskettes, and bs=15k or multiples thereof for 5.25" diskettes.

       The SPARC fd driver is not an unloadable module.

       Under Solaris (x86 Edition), the configuration of the floppy drives is specified in CMOS configuration memory. Use the BIOS  setup  program
       for  the  system  to define the diskette size and density/capacity for each installed drive. Note that MS-DOS may operate the floppy drives
       correctly, even though the CMOS configuration may be in error. Solaris (x86 Edition) relies on the CMOS configuration to be accurate.

SunOS 5.11							    2 Mar 2007								    fd(7D)