NAME

rk − RK-11/RK03 or RK05 disk

DESCRIPTION

Rk?  refers to an entire RK03 disk as a single sequentially-addressed file.  Its 256-word blocks are numbered 0 to 4871. 

The rk 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 RK files begin with rrk and end with a number which selects the same disk as the corresponding rk 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 seek calls should specify a multiple of 512 bytes. 

FILES

/dev/rk∗, /dev/rrk∗

May 16, 1980  —  PDP-11 obsolete