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From: mitch@rock.sgi.com (Tom Mitchell)
Newsgroups: comp.sys.sgi
Subject: Re: tar, 3030 <=> sun
Keywords: tar
Message-ID: <4840@odin.SGI.COM>
Date: 3 Mar 90 01:04:47 GMT
References: <437@skipper.dfrf.nasa.gov>
Sender: news@odin.SGI.COM
Distribution: na
Organization: Silicon Graphics Computer Systems,  Mountain View CA. 94039
Lines: 32

In article <437@skipper.dfrf.nasa.gov> disbrow@skipper.dfrf.nasa.gov (Jim Disbrow) writes:
* Is there some reason why a tar tape created on a 3030 series machine
* can't be read on a Sun 3/280?  Is it just me, or has anyone else


Depending on how the tape controler and interface were
built there may be a byte sex, byte order problem.  There
are two common flavors Big Endian and Little Endian.  Things
get strange when the procesor on the controler is not the
same as the main processor.

Anyhow, this is a common problem and 'dd' has an option (conv=swab)
in it to help with the problem.  Recently SGI as well as other
UNIX vendors have been adding byte swap code directly to
the tape device drivers.  On 4D's look for /dev/tapens.

Scan the man pages until this makes sense.

	dd if=/dev/tape conv=swab | tar tvf -

Then try it.

One other thing -- there are three common physical formats in tape land.
Some tape devices can mix and match.  Check the Sun's mt man
page.  You want to be using the sun QIC-24 flavor device.

Also watch QIC-24 vs. QIC-150 devices.   QIC-150 drives can 
read but not write QIC-24.  Tis sort a one way trap for some.


  Thomas P. Mitchell   --  mitch@sgi.com
	"All things in moderation; including moderation."