[SunRescue] Re: [Packrats] Formatting QIC tapes

[BSD Bob the old greybead BSD freak]

> I just bought a Tandberg 65MB (?) tape drive to install SunOS on my Sun 3,
> but being new to tape drives,  I don't know how to format them and copy
> the files.

Tandberg made several sizes of 1/4 inch cartridge streamer, with the usual
ones in the 65/150/150/525 sizes.  IF yours is one of the larger ones, it
won't work for what you are trying to do on the sun3 machines.  IF you
have a late prom it might work in 150mb mode.  The usual sun3 drives
were 9 track 60mb tape drives.  You can run 150, 300, 450, 600, or 1000
foot tapes through it in 9 track low density mode, and get anywhere from
15mb to 100mb storage capacity.  Contrary to popular belief and marketing
hype, you can use any size tape up to 1000 foot in a 9 track cartridge
drive, PROVIDED you are careful to retension the tapes twice before
writing, and that you properly erase them if changing track density.

The tape does not require formatting.

What I do is something like:  retension twice
                              erase twice
                              dd files appropriately

on master boot tapes.  That usually works fine, for me.
Sunos tapes can be written on 600 or 1000 foot tapes for sun3's.

> The files I got were from compressed tarball files @
> http://www.sunhelp.org/archive/sunos/sun3

There should be a maketape script there in the main tarballs.
If there is not look on sun3arc.krupp.net/BootTapes/  for the
appropriate maketape scripts.  You may have to dittle with the
devices and sleep timings to suit.

> Also, how do I find out what size my tape cartridges are?

Look at the labels.  They should say some number with 150/300/450/600
numbers in them indicating the tape length.  18 track capable tapes
will have a DC6150/6250/6525 numbering possibly, indicating 600 foot
18 track, 1000 foot 18 track, and 1000 foot 19 track high density.
If you use them in 9 track low density mode, consider them to be
600 foot or 1000 foot 60mb or 100mb tapes.

> I was planning on doing the tape
> formatting/copying under Solaris 2.6.

Dunno if it will handle them correctly, but I think it should.
I run all mine off Sunos or NetBSD or FreeBSD.  If Solaris 2.6
does not do anything out of the ordinary, it should work fine.
Just remember to use the maketape scripts to write the files
with the proper block sizes using dd.  Sleep times are not
usually that critical and I cut mine down to 5 seconds between
dd's.

I would not ususally recommend using the early DC300 style tapes,
since they were written with a different oxide compound, and they
tend to flake off at this age and can be a little hard on the
tape heads.  Anything after the early tape compounds such as the
XL450 tapes, or the DC300A tapes, should be usable.  I use the
tiny 50 and 150 foot tapes for boot loaders on NetBSD, but for
Sunos, stick with the 600 foot tapes or 1000 foot tapes for
master boot tapes, with preference for the 600 foot size.

Also, take care around the tape drive rubber capstan wheels.
The are beginning to decompose with age, and if they are in
the least bit sticky and gooey, DON'T EVEN THINK of running
a tape through it.  It will destroy the tape, and goo up
the tape drive.  Tandbergs, usually have good rubber formulations
that don't seem to have the decomposing goo syndrome as much
as Archive or Wangtek drives do.

Good Luck....

Bob Keys