HS(4)               UNIX Programmer's Manual                HS(4)

NAME
     hs - RH11, RH70/RS03, RS04 fixed-head disk

DESCRIPTION
     The files _h_s_0 ... _h_s_7 refer to RS03 disk drives 0 through 7.
     The files _h_s_8 ... _h_s_1_5 refer to RS04 disk drives 0 through
     7.  The RS03 drives are each 1024 512-byte blocks long and
     the RS04 drives are 2048 512-byte blocks long.

     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'
     inteface 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 there-
     fore 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 counts should be a multiple of 512 bytes (a disk
     sector).  Likewise, _l_s_e_e_k calls should specify a multiple of
     512 bytes.

FILES
     /dev/hs??           block files
     /dev/rhs??          raw files

SEE ALSO
     dvhp(4), hk(4), hp(4), ml(4), rf(4), rk(4), rl(4), rm(4),
     rp(4), rx2(4), xp(4)

DIAGNOSTICS
     hs%d: hard error bn %d cs1=%b cs2=%b.  An unrecoverable
     error occured during transfer of the specified sector of the
     specified disk partition.  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.

BUGS
     In raw I/O _r_e_a_d and _w_r_i_t_e(2) truncate file offsets to 512-
     byte block boundaries, and _w_r_i_t_e scribbles on the tail of
     incomplete blocks.  Thus, in programs that are likely to
     access raw devices, _r_e_a_d, _w_r_i_t_e and _l_s_e_e_k(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.

Printed 4/30/83                                                 1