Cartridge tape questions

[neese at adaptex.UUCP]

>I'm confused about quarter-inch cartridge tape drives.  I read that there are
>40MB, 60MB, 120MB, & 150MB tape drives.  I read about "standards" like QIC-24
>and QIC-40.  I hear that some are SCSI, some aren't.  I know about tape
>cartridges like DC300A, DC300XL/P, DC600A and so on.  I hear that some tape
>drives can read tapes created on other, different capacity drives.  I know
>that sometimes you have to swap bytes when loading tapes made on different 
>drives.  And then there's my AT&T 3B2 machine that uses a "streaming" tape
>that must be formatted before it can be written to.
>
>Can someone fill out a table like the following for me to help me understand
>this quagmire?  Many thanks in advance.
>
>   Tape Drive   SCSI or     QIC       Type of    Can read      Swap
>   Capacity       NOT    Standard?   Cartridge   tapes sized   bytes?
>
>My real reason for asking is that we want to get a quarter-inch tape drive for
>a 386 *NIX machine that is as portable as possible (i.e., we'd like to be able
>to make tapes on this machine that can be read on the widest possible variety
>of other *NIX machines).

QIC refers more to the data format than to the actual interface.  With a SCSI
tape drive their is also a QIC standard data format.  For instance, I have
a Cipher ST-150S SCSI 1/4" Tape drive that reads/writes data in QIC-120
(DC-600A) and QIC-150 (DC-600XTD, DC-6150) data formats.  It will also
read QIC-60 data formats (DC-600A).  Whether or not the interface is a SCSI
or a QIC controller, has no bearing on the data format.  Hope this helps.


			Roy Neese
			Adaptec Central Field Applications Engineer
			UUCP @ {texbell,attctc}!cpe!adaptex!neese
				merch!adaptex!neese