prom_rmw − perform VME bus read-modify-write cycles

#include <prom/entrypt.h>
orb_rmw(address, bits)
orh_rmw(address, bits)
orw_rmw(address, bits)
andb_rmw(address, bits)
andh_rmw(address, bits)
andw_rmw(address, bits)

These routines perform VME bus read-modify-write cycles.  The routines
bitwise and’s or bitwise or’s of the contents of the location
and
The ’b’, ’h’, and ’w’ indicate if address is referenced as a byte,
halfword, or word, respectively.
These routines return the original contents of the location