Raw tape buffer vs record size

[Guy Harris]

The most likely reason why the buffer size and address must be even when
reading from tapes is that "physio" is too dumb to realize that tape
controllers can be given an odd byte count or address.  RSX-11M's tape
drivers don't complain; why should UNIX's?  (There is a B_TAPE bit lying
around in the I/O queue header or somesuch place (depending on the flavor of
UNIX you're running) which can be used for this.  Or, if that jams something,
add an extra argument to "physio".)

	Guy Harris
	{seismo,ihnp4,allegra}!rlgvax!guy