		       LINUX ALLOCATED DEVICES

	 Maintained by H. Peter Anvin <Peter.Anvin@linux.org>

		   Last revised: September 20, 1995

This list is the successor to Rick Miller's Linux Device List, which
he stopped maintaining when he lost network access in 1993.  It is a
registry of allocated major device numbers, as well as the recommended
/dev directory nodes for these devices.

This list is now included with the Linux kernel sources in LaTeX and
ASCII form.  This list is also available via FTP from
ftp.yggdrasil.com in the directory /pub/device-list; filename is
devices.<format> where <format> is txt (ASCII), tex (LaTeX), dvi (DVI)
or ps (PostScript).

This document is included by reference into the Linux Filesystem
Standard (FSSTND).  The FSSTND is available via FTP from
tsx-11.mit.edu in the directory /pub/linux/docs/linux-standards/fsstnd.

To have a major number allocated, or a minor number in situations
where that applies (e.g. busmice), please contact me.  Also, if you
have additional information regarding any of the devices listed below,
or if I have made a mistake, I would greatly appreciate a note.

Allocations marked (68k) apply to Linux/68k only.

This document is in the public domain.  The author requests, however,
that semantically altered versions are not distributed without
permission of the author, assuming the author can be contacted without
an unreasonable effort.

  0 		Unnamed devices (NFS mounts, loopback devices)
		  0 = reserved as null device number

  1 char	Memory devices
    		  1 = /dev/mem		Physical memory access
		  2 = /dev/kmem		Kernel virtual memory access
		  3 = /dev/null		Null device
		  4 = /dev/port		I/O port access
		  5 = /dev/zero		Null byte source
		  6 = /dev/core		OBSOLETE - replaced by /proc/kcore
		  7 = /dev/full		Returns ENOSPC on write
		  8 = /dev/random	Nondeterministic random number gen.
		  9 = /dev/urandom	Faster, less secure random number gen.
    block	RAM disk
		  1 = /dev/ramdisk	RAM disk

  2 char	Reserved for PTY's <tytso@athena.mit.edu>
    block	Floppy disks
		  0 = /dev/fd0		First floppy disk autodetect
		  1 = /dev/fd1		Second floppy disk autodetect
		  2 = /dev/fd2		Third floppy disk autodetect
		  3 = /dev/fd3		Fourth floppy disk autodetect

		To specify format, add to the autodetect device number:
		  0 = /dev/fd?		Autodetect format
		  4 = /dev/fd?d360	5.25"  360K in a 360K  drive(1)
		 20 = /dev/fd?h360	5.25"  360K in a 1200K drive(1)
		 48 = /dev/fd?h410	5.25"  410K in a 1200K drive
		 64 = /dev/fd?h420	5.25"  420K in a 1200K drive
		 24 = /dev/fd?h720	5.25"  720K in a 1200K drive
		 80 = /dev/fd?h880	5.25"  880K in a 1200K drive(1)
		  8 = /dev/fd?h1200	5.25" 1200K in a 1200K drive(1)
		 40 = /dev/fd?h1440	5.25" 1440K in a 1200K drive(1)
		 56 = /dev/fd?h1476	5.25" 1476K in a 1200K drive
	  	 72 = /dev/fd?h1494	5.25" 1494K in a 1200K drive
		 92 = /dev/fd?h1600	5.25" 1600K in a 1200K drive(1)

		 12 = /dev/fd?u360	3.5"   360K Double Density
		120 = /dev/fd?u800	3.5"   800K Double Density(1)
		 52 = /dev/fd?u820	3.5"   820K Double Density(2)
		 68 = /dev/fd?u830	3.5"   830K Double Density
		 84 = /dev/fd?u1040	3.5"  1040K Double Density(1)
		 88 = /dev/fd?u1120	3.5"  1120K Double Density(1)
		 28 = /dev/fd?u1440	3.5"  1440K High Density(1)
		124 = /dev/fd?u1600	3.5"  1600K High Density(1)
		 44 = /dev/fd?u1680	3.5"  1680K High Density(3)
		 60 = /dev/fd?u1722	3.5"  1722K High Density
		 76 = /dev/fd?u1743	3.5"  1743K High Density
		 96 = /dev/fd?u1760	3.5"  1760K High Density
		116 = /dev/fd?u1840	3.5"  1840K High Density(3)
		100 = /dev/fd?u1920	3.5"  1920K High Density(1)
		 32 = /dev/fd?u2880	3.5"  2880K Extra Density(1)
		104 = /dev/fd?u3200	3.5"  3200K Extra Density
		108 = /dev/fd?u3520	3.5"  3520K Extra Density
		112 = /dev/fd?u3840	3.5"  3840K Extra Density(1)

		 36 = /dev/fd?CompaQ	Compaq 2880K drive; obsolete?

		(1) Autodetectable format
		(2) Autodetectable format in a Double Density (720K) drive only
		(3) Autodetectable format in a High Density (1440K) drive only

		NOTE: THe letter in the device name (d, q, h or u)
		signifies the type of drive: 5.25" Double Density (d),
		5.25" Quad Density (q), 5.25" High Density (h) or 3.5"
		(any model, u).  The use of the capital letters D, H
		and E for the 3.5" models have been deprecated, since
		the drive type is insignificant for these devices.

  3 char	Reserved for pty's <tytso@athena.mit.edu>
    block	First MFM, RLL and IDE hard disk/CD-ROM interface
    		  0 = /dev/hda		Master: whole disk (or CD-ROM)
		 64 = /dev/hdb		Slave: whole disk (or CD-ROM)
		
		For partitions, add to the whole disk device number:
		  0 = /dev/hd?		Whole disk
		  1 = /dev/hd?1		First primary partition
		  2 = /dev/hd?2		Second primary partition
		  3 = /dev/hd?3		Third primary partition
		  4 = /dev/hd?4		Fourth primary partition
		  5 = /dev/hd?5		First logical partition
		  6 = /dev/hd?6		Second logical partition
		  7 = /dev/hd?7		Third logical partition
		    ...
		 63 = /dev/hd?63	59th logical partition

  4 char	TTY devices
    		  0 = /dev/console	Console device

		  1 = /dev/tty1		First virtual console
		      ...
		 63 = /dev/tty63	63rd virtual console
		 64 = /dev/ttyS0	First serial port
		      ...
		127 = /dev/ttyS63	64th serial port
		128 = /dev/ptyp0	First pseudo-tty master
		      ...
		191 = /dev/ptysf	64th pseudo-tty master
		192 = /dev/ttyp0	First pseudo-tty slave
		      ...
		255 = /dev/ttysf	64th pseudo-tty slave

		Pseudo-tty's are named as follows:
		* Masters are "pty", slaves are "tty";
		* the fourth letter is one of p, q, r, s indicating
		  the 1st, 2nd, 3rd, 4th series of 16 pseudo-ttys each, and
		* the fifth letter is one of 0123456789abcdef indicating
		  the position within the series.

  5 char	Alternate TTY devices
    		  0 = /dev/tty		Current TTY device
		 64 = /dev/cua0		Callout device corresponding to ttyS0
		      ...
		127 = /dev/cua63	Callout device corresponding to ttyS63

  6 char	Parallel printer devices
    		  0 = /dev/lp0		First parallel printer (0x3bc)
		  1 = /dev/lp1		Second parallel printer (0x378)
		  2 = /dev/lp2		Third parallel printer (0x278)

		Not all computers have the 0x3bc parallel port; hence
		the "first" printer may be either /dev/lp0 or
		/dev/lp1.

  7 char	Virtual console capture devices
    		  0 = /dev/vcs		Current vc text contents
		  1 = /dev/vcs1		tty1 text contents
		      ...
		 63 = /dev/vcs63	tty63 text contents
		128 = /dev/vcsa		Current vc text/attribute contents
		129 = /dev/vcsa1	tty1 text/attribute contents
		      ...
		191 = /dev/vcsa63	tty63 text/attribute contents
	
		NOTE: These devices permit both read and write access.

  8 block	SCSI disk devices
    		  0 = /dev/sda		First SCSI disk whole disk
		 16 = /dev/sdb		Second SCSI disk whole disk
		 32 = /dev/sdc		Third SCSI disk whole disk
  		      ...
		240 = /dev/sdp		Sixteenth SCSI disk whole disk

		Partitions are handled in the same way as for IDE
		disks (see major number 3) except that the limit on
		logical partitions is 11.

  9 char	SCSI tape devices
    		  0 = /dev/st0		First SCSI tape
		  1 = /dev/st1		Second SCSI tape
		      ...
		128 = /dev/nst0		First SCSI tape, no rewind-on-close
		129 = /dev/nst1		Second SCSI tape, no rewind-on-close
		      ...
    block	Multiple disk devices
		  0 = /dev/md0		First device group
		  1 = /dev/md1		Second device group
		      ...

		The multiple devices driver is used to span a
		filesystem across multiple physical disks.

 10 char	Non-serial mice, misc features
		  0 = /dev/logibm	Logitech bus mouse
		  1 = /dev/psaux	PS/2-style mouse port
		  2 = /dev/inportbm	Microsoft Inport bus mouse
		  3 = /dev/atibm	ATI XL bus mouse
		  4 = /dev/jbm		J-mouse
		  4 = /dev/amigamouse	Amiga Mouse (68k)
		  5 = /dev/atarimouse	Atari Mouse (68k)
		128 = /dev/beep		Fancy beep device
		129 = /dev/modreq	Kernel module load request

		The use of the suffix -mouse instead of -bm or -aux
		has also been used.

 11 block	SCSI CD-ROM devices
    		  0 = /dev/sr0		First SCSI CD-ROM
		  1 = /dev/sr1		Second SCSI CD-ROM
		      ...

		The prefix /dev/scd instead of /dev/sr has been used
		as well, and might make more sense.

 12 char	QIC-02 tape
		  2 = /dev/ntpqic11	QIC-11, no rewind-on-close
		  3 = /dev/tpqic11	QIC-11, rewind-on-close
		  4 = /dev/ntpqic24	QIC-24, no rewind-on-close
		  5 = /dev/tpqic24	QIC-24, rewind-on-close
		  6 = /dev/ntpqic120	QIC-120, no rewind-on-close
		  7 = /dev/tpqic120	QIC-120, rewind-on-close
		  8 = /dev/ntpqic150	QIC-150, no rewind-on-close
		  9 = /dev/tpqic150	QIC-150, rewind-on-close

		The device names specified are proposed -- if there
		are "standard" names for these devices, please let me know.

    block	MSCDEX CD-ROM callback support
		  0 = /dev/dos_cd0	First MSCDEX CD-ROM
		  1 = /dev/dos_cd1	Second MSCDEX CD-ROM
		      ...

 13 char	PC speaker
		  0 = /dev/pcmixer	Emulates /dev/mixer
		  1 = /dev/pcsp		Emulates /dev/dsp (8-bit)
		  4 = /dev/pcaudio	Emulates /dev/audio
		  5 = /dev/pcsp16	Emulates /dev/dsp (16-bit)
    block	8-bit MFM/RLL/IDE controller
		  0 = /dev/xda		First XT disk whole disk
		 64 = /dev/xdb		Second XT disk whole disk

		Partitions are handled in the same way as IDE disks
		(see major number 3).

 14 char	Sound card
		  0 = /dev/mixer	Mixer control
		  1 = /dev/sequencer	Audio sequencer
		  2 = /dev/midi00	First MIDI port
		  3 = /dev/dsp		Digital audio
		  4 = /dev/audio	Sun-compatible digital audio
		  6 = /dev/sndstat	Sound card status information
		  8 = /dev/sequencer2	Sequencer -- alternate device
		 16 = /dev/mixer1	Second soundcard mixer control
		 17 = /dev/patmgr0	Sequencer patch manager
		 18 = /dev/midi01	Second MIDI port
		 19 = /dev/dsp1		Second soundcard digital audio
		 20 = /dev/audio1	Second soundcard Sun digital audio
		 33 = /dev/patmgr1	Sequencer patch manager
		 34 = /dev/midi02	Third MIDI port
		 50 = /dev/midi03	Fourth MIDI port
    block	BIOS harddrive callback support
		  0 = /dev/dos_hda	First BIOS harddrive whole disk
		 64 = /dev/dos_hdb	Second BIOS harddrive whole disk
		128 = /dev/dos_hdc	Third BIOS harddrive whole disk
		192 = /dev/dos_hdd	Fourth BIOS harddrive whole disk

		Partitions are handled in the same way as IDE disks
		(see major number 3).

 15 char	Joystick
		  0 = /dev/js0		First joystick
		  1 = /dev/js1		Second joystick
    block	Sony CDU-31A/CDU-33A CD-ROM
		  0 = /dev/sonycd	Sony CDU-31a CD-ROM

 16 char	Reserved for scanners
    block	GoldStar CD-ROM
		  0 = /dev/gscd		GoldStar CD-ROM

 17 char	Chase serial card
		  0 = /dev/ttyH0	First Chase port
		  1 = /dev/ttyH1	Second Chase port
		      ...
    block	Optics Storage CD-ROM
		  0 = /dev/optcd	Optics Storage CD-ROM

 18 char	Chase serial card - alternate devices
		  0 = /dev/cuh0		Callout device corresponding to ttyH0
		  1 = /dev/cuh1		Callout device corresponding to ttyH1
		      ...
    block	Sanyo CD-ROM
		  0 = /dev/sjcd		Sanyo CD-ROM

 19 char	Cyclades serial card
		 32 = /dev/ttyC0	First Cyclades port
		      ...
		 63 = /dev/ttyC31	32nd Cyclades port
		
		It would make more sense for these to start at 0...

    block	"Double" compressed disk
		  0 = /dev/double0	First compressed disk
		      ...
		  7 = /dev/double7	Eighth compressed disk
		128 = /dev/cdouble0	Mirror of first compressed disk
		      ...
		135 = /dev/cdouble7	Mirror of eighth compressed disk

		See the Double documentation for the meaning of the
		mirror devices.

 20 char	Cyclades serial card - alternate devices
		 32 = /dev/cub0		Callout device corresponding to ttyC0
		      ...
		 63 = /dev/cub31	Callout device corresponding to ttyC31
    block	Hitachi CD-ROM (under development)
		  0 = /dev/hitcd	Hitachi CD-ROM

 21 char	Generic SCSI access
		  0 = /dev/sg0		First generic SCSI device
		  1 = /dev/sg1		Second generic SCSI device
		      ...

 22 char	Digiboard serial card
		  0 = /dev/ttyD0	First Digiboard port
		  1 = /dev/ttyD1	Second Digiboard port
		      ...
    block	Second IDE hard disk/CD-ROM interface
    		  0 = /dev/hdc		Master: whole disk (or CD-ROM)
		 64 = /dev/hdd		Slave: whole disk (or CD-ROM)
		
		Partitions are handled the same way as for the first
		interface (see major number 3).

 23 char	Digiboard serial card - alternate devices
		  0 = /dev/cud0		Callout device corresponding to ttyD0
		  1 = /dev/cud1		Callout device corresponding to ttyD1
		      ...
    block	Mitsumi proprietary CD-ROM
		  0 = /dev/mcd		Mitsumi CD-ROM

 24 char	Stallion serial card
		  0 = /dev/ttyE0	Stallion port 0 card 0
		  1 = /dev/ttyE1	Stallion port 1 card 0
		      ...
		 64 = /dev/ttyE64	Stallion port 0 card 1
		 65 = /dev/ttyE65	Stallion port 1 card 1
		      ...
		128 = /dev/ttyE128	Stallion port 0 card 2
		129 = /dev/ttyE129	Stallion port 1 card 2
		      ...
		192 = /dev/ttyE192	Stallion port 0 card 3
		193 = /dev/ttyE193	Stallion port 1 card 3
		      ...
    block	Sony CDU-535 CD-ROM
		  0 = /dev/cdu535	Sony CDU-535 CD-ROM

 25 char	Stallion serial card - alternate devices
		  0 = /dev/cue0		Callout device corresponding to ttyE0
		  1 = /dev/cue1		Callout device corresponding to ttyE1
		      ...
		 64 = /dev/cue64	Callout device corresponding to ttyE64
		 65 = /dev/cue65	Callout device corresponding to ttyE65
		      ...
		128 = /dev/cue128	Callout device corresponding to ttyE128
		129 = /dev/cue129	Callout device corresponding to ttyE129
		      ...
		192 = /dev/cue192	Callout device corresponding to ttyE192
		193 = /dev/cue193	Callout device corresponding to ttyE193
		      ...
    block	First Matsushita (Panasonic/SoundBlaster) CD-ROM
		  0 = /dev/sbpcd0	Panasonic CD-ROM controller 0 unit 0
		  1 = /dev/sbpcd1	Panasonic CD-ROM controller 0 unit 1
		  2 = /dev/sbpcd2	Panasonic CD-ROM controller 0 unit 2
		  3 = /dev/sbpcd3	Panasonic CD-ROM controller 0 unit 3

 26 char	Frame grabbers
		  0 = /dev/wvisfgrab	Quanta WinVision frame grabber
    block	Second Matsushita (Panasonic/SoundBlaster) CD-ROM
		  0 = /dev/sbpcd4	Panasonic CD-ROM controller 1 unit 0
		  1 = /dev/sbpcd5	Panasonic CD-ROM controller 1 unit 1
		  2 = /dev/sbpcd6	Panasonic CD-ROM controller 1 unit 2
		  3 = /dev/sbpcd7	Panasonic CD-ROM controller 1 unit 3

 27 char	QIC-117 tape
		  0 = /dev/ftape	QIC-117 tape
    block	Third Matsushita (Panasonic/SoundBlaster) CD-ROM
		  0 = /dev/sbpcd8	Panasonic CD-ROM controller 2 unit 0
		  1 = /dev/sbpcd9	Panasonic CD-ROM controller 2 unit 1
		  2 = /dev/sbpcd10	Panasonic CD-ROM controller 2 unit 2
		  3 = /dev/sbpcd11	Panasonic CD-ROM controller 2 unit 3

 28 char	Stallion serial card - card programming
		  0 = /dev/staliomem0	First Stallion card I/O memory
		  1 = /dev/staliomem1	Second Stallion card I/O memory
		  2 = /dev/staliomem2	Third Stallion card I/O memory
		  3 = /dev/staliomem3	Fourth Stallion card I/O memory
    block	Fourth Matsushita (Panasonic/SoundBlaster) CD-ROM
		  0 = /dev/sbpcd12	Panasonic CD-ROM controller 3 unit 0
		  1 = /dev/sbpcd13	Panasonic CD-ROM controller 3 unit 1
		  2 = /dev/sbpcd14	Panasonic CD-ROM controller 3 unit 2
		  3 = /dev/sbpcd15	Panasonic CD-ROM controller 3 unit 3
    block	ACSI disk (68k)
		  0 = /dev/ada		First ACSI disk whole disk
		 16 = /dev/adb		Second ACSI disk whole disk
		 32 = /dev/adc		Third ACSI disk whole disk
		      ...
		240 = /dev/adp		16th ACSI disk whole disk

		Partitions are handled in the same way as for IDE
		disks (see major number 3) except that the limit on
		logical partitions is 11.

 29 char	Universal frame buffer
		  0 = /dev/fb0current	First frame buffer
		  1 = /dev/fb0autodetect
		      ...
		 16 = /dev/fb1current	Second frame buffer
		 17 = /dev/fb1autodetect
		      ...
    block	Aztech/Orchid/Okano/Wearnes CD-ROM
		  0 = /dev/aztcd	Aztech CD-ROM

		The universal frame buffer device is currenly only
		supported on Linux/68k.  The "current" device accesses
		the fame buffer at current resolution; the
		"autodetect" one at bootup (default) resolution.
		Minor numbers 2-15 within each frame buffer assignment
		are used for specific device-dependent resolutions.
		There appears to be no standard naming for these devices.

 30 char	iBCS-2 compatibility devices
		  0 = /dev/socksys	Socket access
		  1 = /dev/spx		SVR3 local X interface
		  2 = /dev/inet/arp	Network access
		  2 = /dev/inet/icmp	Network access
		  2 = /dev/inet/ip	Network access
		  2 = /dev/inet/udp	Network access
		  2 = /dev/inet/tcp	Network access

		iBCS-2 requires /dev/nfsd to be a link to
		/dev/socksys, and /dev/X0R to be a link to /dev/null.

    block	Philips LMS CM-205 CD-ROM
		  0 = /dev/cm205cd	Philips LMS CM-205 CD-ROM

		/dev/lmscd is an older name for this device.  This
		driver does not work with the CM-205MS CD-ROM.

 31 char	MPU-401 MIDI
		  0 = /dev/mpu401data	MPU-401 data port
		  1 = /dev/mpu401stat	MPU-401 status port
    block	ROM/flash memory card
		  0 = /dev/rom0		First ROM card (rw)
		      ...
		  7 = /dev/rom7		Eighth ROM card (rw)
		  8 = /dev/rrom0	First ROM card (ro)
		      ...
		 15 = /dev/rrom7	Eighth ROM card (ro)
		 16 = /dev/flash0	First flash memory card (rw)
		      ...
		 23 = /dev/flash7	Eighth flash memory card (rw)
		 24 = /dev/rflash0	First flash memory card (ro)
		      ...
		 31 = /dev/rflash7	Eighth flash memory card (ro)

		The read-write (rw) devices support back-caching
		written data in RAM, as well as writing to flash RAM
		devices.  The read-only devices (ro) support reading
		only.

 32 char	Specialix serial card
		  0 = /dev/ttyX0	First Specialix port
		  1 = /dev/ttyX1	Second Specialix port
		      ...
    block	Philips LMS CM-206 CD-ROM
		  0 = /dev/cm206cd	Philips LMS CM-206 CD-ROM

 33 char	Specialix serial card - alternate devices
		  0 = /dev/cux0		Callout device corresponding to ttyX0
		  1 = /dev/cux1		Callout device corresponding to ttyX1
		      ...
    block	Third IDE hard disk/CD-ROM interface
    		  0 = /dev/hde		Master: whole disk (or CD-ROM)
		 64 = /dev/hdf		Slave: whole disk (or CD-ROM)

		Partitions are handled the same way as for the first
		interface (see major number 3).

 34 char	Z8530 HDLC driver
		  0 = /dev/sc1		First Z8530, first port
		  1 = /dev/sc2		First Z8530, second port
		  2 = /dev/sc3		Second Z8530, first port
		  3 = /dev/sc4		Second Z8530, second port
		      ...
    block	Fourth IDE hard disk/CD-ROM interface
    		  0 = /dev/hdg		Master: whole disk (or CD-ROM)
		 64 = /dev/hdh		Slave: whole disk (or CD-ROM)
		
		Partitions are handled the same way as for the first
		interface (see major number 3).

 35 char	tclmidi MIDI driver
		  0 = /dev/midi0	First MIDI port, kernel timed
		  1 = /dev/midi1	Second MIDI port, kernel timed
		  2 = /dev/midi2	Third MIDI port, kernel timed
		  3 = /dev/midi3	Fourth MIDI port, kernel timed
	         64 = /dev/rmidi0	First MIDI port, untimed
	         65 = /dev/rmidi1	Second MIDI port, untimed
	         66 = /dev/rmidi2	Third MIDI port, untimed
	         67 = /dev/rmidi3	Fourth MIDI port, untimed
		128 = /dev/smpte0	First MIDI port, SMPTE timed
		129 = /dev/smpte1	Second MIDI port, SMPTE timed
		130 = /dev/smpte2	Third MIDI port, SMPTE timed
		131 = /dev/smpte3	Fourth MIDI port, SMPTE timed
    block	Modular RAM disk device
		  0 = /dev/ram0		First modular RAM disk
		  1 = /dev/ram1		Second modular RAM disk
		      ...
		255 = /dev/ram255	256th modular RAM disk

 36 char	Netlink support
		  0 = /dev/route	Routing, device updates, kernel to user
		  1 = /dev/skip		enSKIP security cache control
    block	MCA ESDI hard disk
		  0 = /dev/eda		First ESDI disk whole disk
		 64 = /dev/edb		Second ESDI disk whole disk
		      ...

		Partitions are handled in the same way as IDE disks
		(see major number 3).

 37-41		UNALLOCATED

 42		Demo/sample use

		This number is indended for use in sample code, as
		well as a general "example" device number.  It
		should never be used for a device driver that is being
		distributed; either obtain an official number or use
		the local/experimental range.  The sudden addition or
		removal of a driver with this number should not cause
		ill effects to the system (bugs excepted.)

 43-223		UNALLOCATED

224-239		SEE NOTE

		This range is currently assigned as part of the
		local/experimental range.  However, because of the
		Linux way of setting a limit on the highest device
		number in the system, currently set at 63 by default,
		I am considering changing the local/experimental use
		to 60-63, 120-127, 240-254.  If you are currently
		using the range 224-239 and such a change would pose a
		problem for you, please contact <hpa@storm.net> as
		soon as possible.

240-254		LOCAL USE
		Allocated for local/experimental use

		Please note that MAX_CHRDEV and MAX_BLKDEV in
		linux/include/linux/major.h must be set to a value
		greater than the highest used major number.  For a
		kernel using local/experimental devices, it is
		probably easiest to set both of these equal to 256.  The
		memory cost above using the default value of 64 is 3K.

255		RESERVED




	ADDITIONAL /dev DIRECTORY ENTRIES

This section details additional entries that should or may exist in
the /dev directory.  It is preferred that symbolic links use the same
form (absolute or relative) as is indicated here.  Links are
classified as "hard" or "symbolic" depending on the preferred type of
link; if possible, the indicated type of link should be used.


	Compulsory links

These links should exist on all systems:

/dev/fd		/proc/self/fd	symbolic	File descriptors
/dev/stdin	fd/0		symbolic	stdin file descriptor
/dev/stdout	fd/1		symbolic	stdout file descriptor
/dev/stderr	fd/2		symbolic	stderr file descriptor


	Recommended links

It is recommended that these links exist on all systems:

/dev/X0R	null		symbolic	Used by iBCS-2
/dev/nfsd	socksys		symbolic	Used by iBCS-2
/dev/core	/proc/kcore	symbolic	Backward compatibility
/dev/scd?	/dev/sr?	hard		Alternate SCSI CD-ROM name


	Locally defined links

The following links may be established locally to conform to the
configuration of the system.  This is merely a tabulation of existing
practice, and does not constitute a recommendation.  However, if they
exist, they should have the following uses.

/dev/mouse	mouse port	symbolic	Current mouse device
/dev/tape	tape device	symbolic	Current tape device
/dev/cdrom	CD-ROM device	symbolic	Current CD-ROM device
/dev/cdwriter	CD-writer	symbolic	Current CD-writer device
/dev/scanner	scanner		symbolic	Current scanner device
/dev/modem	modem port	symbolic	Current dialout device
/dev/root	root device	symbolic	Current root filesystem
/dev/swap	swap device	symbolic	Current swap device

/dev/modem should not be used for a modem which supports dialin as
well as dialout, as it tends to cause lock file problems.  If it
exists, /dev/modem shold point to the appropriate dialout (alternate)
device.

For SCSI devices, /dev/tape and /dev/cdrom should point to the
``cooked'' devices (/dev/st* and /dev/sr*, respectively), whereas
/dev/cdwriter and /dev/scanner should point to the appropriate generic
SCSI devices (/dev/sg*).

/dev/mouse may point to a dialout (alternate) TTY device, a hardware
mouse device, or a socket for a mouse driver program.

	Sockets and pipes

Non-transient sockets and named pipes may exist in /dev.  Common entries are:

/dev/printer	socket		lpd local socket
/dev/log	socket		syslog local socket
