9-track tape info (summary)

[Robert Willis]

I previously asked for information about reading and writing 9-track tapes
in various formats.  Here is a summary of the information which I received.


Besides finding out some machines at BBN that have magnetic reel tape drives,
I received the following information:

0)  General information:

	It is always possible to read a 9 track tape on a Unix machine; the
	recording method is standard. The only thing is decoding the format
	of the blocks. 


1)  About available hardware:

	Sun sells Fujitsu 9-track tapes as a quite standard part of their
	product line.


2)  About software distributed by Sun (and most other Un*x vendors):

	dd(1) [or possibly ddx(1)] is it.  It doesn't know about any 
	vendor-specific formats, although it can do EBCDIC <-> ASCII
	conversions.

	In the last resort you can write your own program. The interface 
	is simple. read(2) returns the next tape block on the tape and 
	the length of the block read.  So call read with a large enough 
	buffer.  A tape mark looks like an EOF. Two tape marks indicates
	logical end of tape.

	If there are multiple files on the tape, use the tape device that
	does not automatically rewind the tape.  You will need a separate 
	dd(1) command for each file on the tape [in most cases].

3)  Other relevant software:

	Also, a stop by your local sources archive should get you ansitape,
	a utility which reads and writes ANSI standard labeled tapes, which
	happen to be what VMS uses in case you need to read VAX tapes.

	There was a package called MAG written by Dick Grune at the 
	University of Amsterdam, which was on comp.unix.sources about
	a year ago. You should be able to get it from the archives. 
	It handles the IBM, and Cyber formats, does ebcdic to ascii,
	ascii to ebcdic, etc. All in all it's a real nice package.

	There have been a number of UNIX utilities written and posted to
	the net to handle this format; some of them depend on BSD magnetic 
	tape "ioctl"s, but SunOS supports them.  They have names like
	"ansitape", "ansitar", "vmstape", etc..

	VMS 'backup' tape readers are rumored to exist

4)  This is not Sun related, but:

	Ultrix comes with an excellent ANSI tape program (binary
	only) that can even read VMS magtapes.