Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!amdcad!ames!aurora!labrea!decwrl!decvax!mkunix..DEC.COM!tyager
From: tyager@mkunix.DEC.COM (Tom Yager)
Newsgroups: comp.unix.xenix
Subject: Tape drive
Message-ID: <148@mkunix.DEC.COM>
Date: 3 Feb 88 01:37:49 GMT
Organization: Digital Equipment Corporation Westborough, MA.
Lines: 59
Keywords: SCO,386,Xenix,Unix,moose

Someone posted something here earlier asking about "cheap" tape drives.
I bought the Irwin 40Mb internal drive to go with my MDS 20MHz '386 &
SCO; here's my impressions:

(first, the bad news...)
MINUSES:
o The drive is not compatible with the 'tape' utility (and SCO says it
  probably never will be).
o It won't run on most 20MHz '386 boxes--SCO admits the problem is in
  the device driver and they plan to address it "shortly." I solved
  this by replacing my 40MHz crystal with a 32.??? MHz one. When they
  fix the driver, I'll boost it again (a noticable difference!).
o Tapes need to be formatted and verified before they can be used. A
  tape formatted under MSDOS using Irwin's utilities can't be used under
  SCO. Format/verify is NOT a quick procedure--I think it's over 30
  minutes, but I can't recall for certain. I'll post timings for anyone
  who's interested (mail me).
o The driver is a real memory hog. If you're running on a minimum memory
  system (i.e. 1 meg), you might not be able to do backups in multi-user
  mode. There's a good reason for this (see below).

PLUSES:
o It's the cheapest 40Mb tape drive I've seen (of the ones that can be
  used with SCO, that is).
o It is FAST. Again, I'll post timings if I get enough mail, but believe
  me: it's more than adequate backup for my system which has 90MB of hard
  disk.
o The small (DC2000) tapes are nice. Easy to carry, mail, store, etc.
o The driver will allocate a huge buffer for the device so that data is
  shipped to the drive "nearly streamed," that is, much fewer
  write-stop-reverse-stop-read-stop-etc...
o A separate device special file, "/dev/rctminiv" (as opposed to just
  "rctmini") verifies the tape write with a readback. It seems to be
  just a readability check and not a verify against the original data,
  but it's enough. The ECC takes care of the rest.
o I think it's the easiest to install: plug it in as floppy drive B and
  slide it in! I was able to install mine without messing with a single
  jumper or DIP switch or even CMOS setup.
o The pre-format and verify, pain though it is, seems to work. I have
  done dozens of backups since I originally installed the drive and
  have not had a single read/write failure.
o The DOS software Irwin provides is quite good and allows for multiple
  archives on a single tape. It has both menu-driven and command line
  interfaces. It's interactive mode is nice and fashioned similar to
  "Xtree".
o I've used tar, dump, restore, and cpio with no problems, and used them
  all while in multi-user mode.

I'm anticipating that there will be those who feel moved to respond
to this by defending whatever drive they chose. I'm not beating down any
other product, and I haven't personally tried any other drive. I just
know that the Irwin works reliably, is supported well under SCO, and
can be afforded by people who still insist on daily feedings.

-- 
Tom Yager, Digital Ultrix Support ("It MUST be the hardware!")
U.S. Mail: DEC, 14 Walkup Drive YWO/C9, Westborough, MA 01581
uucp:      ...decvax!mkunix!tyager
"Eat a live toad in the morning; nothing worse will happen all day."