The memory pseudo-driver is used for several HP-UX special files:

	* /dev/mem, which is the (core) memory driver; /dev/mem will
	  contain a copy of the actual image in physical RAM at any
	  point in time.

	* /dev/kmem, which is the kernel memory driver, will have
	  an image of the memory used only by the HP-UX kernel.

	* /dev/null is the "bit-bucket", which when read from will
	  always return a read length of 0 bytes (EOF) and will
	  always be writeable, but anything written to this device
	  is lost.
