RL(4)							     Kernel Interfaces Manual							     RL(4)

NAME

       rl - RL-11/RL01, RL02 moving-head disk

SYNOPSIS

       /sys/conf/SYSTEM:
	    NRL  rl_drives # RL01/02

       /etc/dtab:
	    #Name Unit# Addr   Vector Br Handler(s)	 # Comments
	    rl	  ?	174400 160    5  rlintr 	 # rl-01/02

       major device number(s):
	    raw: 16
	    block: 7
       minor device encoding:
	    bits 0007 specify partition of RL drive
	    bits 0070 specify RL drive

DESCRIPTION

       The  block  files  access  the disk via the system's normal buffering mechanism and may be read and written without regard to physical disk
       records.  There is also a `raw' interface which provides for direct transmission between the disk and the user's read or write  buffer.	 A
       single  read  or  write	call results in exactly one I/O operation and therefore raw I/O is considerably more efficient when many words are
       transmitted.  The names of the raw files conventionally begin with an extra `r.'

       In raw I/O the buffer must begin on a word (even) boundary, and counts should be a multiple of 512 bytes (a disk  sector).   Likewise  seek
       calls should specify a multiple of 512 bytes.

DISK SUPPORT

       The RL01 drives are each 10240 blocks long and the RL02 drives are 20480 blocks long.

       On  a  RL02  there is room for a full sized root ('a') partition and a reasonable sized swap ('b') partition.  The RL01 can only (realisti-
       cally) have a single 5mb partition.

FILES

       /dev/rl[0-3][a-h]   block files
       /dev/rrl[0-3][a-h]  raw files
       /dev/MAKEDEV	   script to create special files
       /dev/MAKEDEV.local  script to localize special files

SEE ALSO

       hk(4), ra(4), ram(4), rk(4), rp(4), rx(4), si(4), xp(4), dtab(5), autoconfig(8)

DIAGNOSTICS

       rl%d: hard error sn%d cs=%b da=%b.  An unrecoverable error occurred during transfer of the specified sector of  the  specified  disk.   The
       contents of the two error registers are also printed in octal and symbolically with bits decoded.  The error was either unrecoverable, or a
       large number of retry attempts could not recover the error.

       rl%d: hard error sn%d mp=%b da=%b.  An unrecoverable drive error occured during transfer of the specified sector  of  the  specified  disk.
       The  contents of the two error registers are also printed in octal and symbolically with bits decoded.  The error was either unrecoverable,
       or a large number of retry attempts could not recover the error.

       rl%d: write locked.  The write protect switch was set on the drive when a write was attempted.  The write operation is not recoverable.

       rl%d: can't get status.	A ``get status'' command on the specified drive failed.  The error is unrecoverable.

BUGS

       In raw I/O read and write(2) truncate file offsets to 512-byte block boundaries, and write scribbles on	the  tail  of  incomplete  blocks.
       Thus, in programs that are likely to access raw devices, read, write and lseek(2) should always deal in 512-byte multiples.

       DEC-standard error logging should be supported.

       A program to analyze the logged error information (even in its present reduced form) is needed.

3rd Berkeley Distribution					  August 20, 1987							     RL(4)