RF (IV)                      3/15/72                      RF (IV)





NAME            rf  --  RF11-RS11 fixed-head disk file



DESCRIPTION     This file refers to the concatenation of both

                RS-11 disks.  It may be either read or written,

                although writing is inherently very dangerous,

                since a file system resides there.



                The disk contains 2048 256-word blocks, numbered

                0 to 2047.  Like the other block-structured de-

                vices (TC, RK) this file is addressed in blocks,

                not bytes.  This has two consequences: seek calls

                refer to block numbers, not byte numbers; and se-

                quential reading or writing always advance the

                read or write pointer by at least one block.

                Thus successive reads of 10 characters from this

                file actually read the first 10 characters from

                successive blocks.



FILES           /dev/rf0



SEE ALSO        tc(IV), rk(IV)



BUGS            The fact that this device is addressed in terms

                of blocks, not bytes, is extremely unfortunate.

                It is due entirely to the fact that read and

                write pointers (and consequently the arguments to

                seek) are single-precision numbers.