1/4 tape drive formats

[Bill Johnston [csam]]

Can someone give me a brief description of the differences in the
formats of 1/4" tape cartridges used on small UNIX systems? In
particular, do 'archive' and 'streamer' refer to formats on tape, or
different types of drives, or both? Are these drives or formats
supposed to be compatible? (I would guess not since I have tried to
move tapes between our SUN and Integrated Solutions 4.2 systems without
success.) The archive (trade name?) 1/4" drive on the Sun certainly
works differently than the 1/4" drive on the IS system. On the Sun it
seems as though every block on tape is written, then backspaced over
and read. It is VERY slow. On the IS box the drive behaves as I would
expect a streamer drive to; lots of tape motion, with stops mostly at
the end of files.  Backspace seems not to be possible on this latter
type of drive, tar u won't work.  It is my understanding that there are
several different recording densities in use, but that the drives can
sense this and adapt.
	Thanks, Bill [johnston at lbl-csam]