NAME

rl − RL-11/RL01 disk

DESCRIPTION

rl0, ..., rl3 refer to an entire RL01 disk drive as a single sequentially-addressed file.  Its 256-word blocks are numbered 0 to 10239. 

The rl 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 call and therefore raw I/O is considerably more efficient when many words are transmitted.  The names of the raw RL files begin with rrl and end with a number which selects the same disk as the corresponding rl file. 

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

FILES

/dev/rl∗, /dev/rrl∗

May 16, 1980