[comp.unix.i386] 150 Mb Archive Viper can't write 60 Mb tapes???

bill@twg.UUCP (Bill Irwin) (07/01/90)

The sould of this when I heard it was so absurd I just had to ask the net
right  away.   We are just installing an Archive Viper 150Mb  tape  drive
into  an i386 running SCO UNIX (current release).  One of the technicians
said  that  it could read 60Mb tapes produced on a 60Mb streamer, but  it
couldn't produce tapes that could be read by the 60Mb.

I'll  be  digging  into the manual when I get into the office  after  the
weekend,  but  I thought I would throw this out now because I can't  wait
for the answer.
-- 
Bill Irwin - TWG The Westrheim Group - Vancouver, BC, Canada
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
uunet!van-bc!twg!bill     (604) 431-9600 (voice) |     UNIX Systems
bill@twg.UUCP             (604) 431-4629 (fax)   |     Integration

cpcahil@virtech.uucp (Conor P. Cahill) (07/01/90)

In article <212@twg.UUCP> bill@twg.UUCP (Bill Irwin) writes:
>The sould of this when I heard it was so absurd I just had to ask the net
>right  away.   We are just installing an Archive Viper 150Mb  tape  drive
>into  an i386 running SCO UNIX (current release).  One of the technicians
>said  that  it could read 60Mb tapes produced on a 60Mb streamer, but  it
>couldn't produce tapes that could be read by the 60Mb.

This is true for most, if not all of the high density tape drives, reguardless
of the manufacturer.  The highest density drive that I know of, that will still
write 60 MB tapes are the 120MB drives.


-- 
Conor P. Cahill            (703)430-9247        Virtual Technologies, Inc.,
uunet!virtech!cpcahil                           46030 Manekin Plaza, Suite 160
                                                Sterling, VA 22170 

md@sco.COM (Michael Davidson) (07/02/90)

bill@twg.UUCP (Bill Irwin) writes:
>The sould of this when I heard it was so absurd I just had to ask the net
>right  away.   We are just installing an Archive Viper 150Mb  tape  drive
>into  an i386 running SCO UNIX (current release).  One of the technicians
>said  that  it could read 60Mb tapes produced on a 60Mb streamer, but  it
>couldn't produce tapes that could be read by the 60Mb.

I'm afraid that your technician is absolutely right....
A 150 Meg drive will ONLY write 150 Meg tapes.
The 150 Meg drives are *supposed* to be able to read 60 Meg
tapes, but "your mileage may vary" on this one so be sure to
check this out with some sample 60 Meg tapes written on the
60 Meg drives that you actually care about BEFORE you
get yourself into a dire emergency when you actually
need to read 60 Meg tapes.

sralston@srwic.UUCP (Steve Ralston) (07/02/90)

In article <212@twg.UUCP> bill@twg.UUCP (Bill Irwin) writes:
>The sound of this when I heard it was so absurd I just had to ask the net
>right  away.   We are just installing an Archive Viper 150Mb  tape  drive
>into  an i386 running SCO UNIX (current release).  One of the technicians
>said  that  it could read 60Mb tapes produced on a 60Mb streamer, but  it
>couldn't produce tapes that could be read by the 60Mb.
>
Sorry I can't help you with your 150 Mb Archive Viper problems, but...

If you think that's absurd, how about SCO UNIX not being able to read
QIC-40 tapes written by SCO Xenix (2.3.2).  These tapes were written using
both cpio and tar after installing the Xenix QIC-40 tape driver.  After
installing the SCO UNIX QIC-40 tape driver, I get get END-OF-MEDIA when
trying to read cpio tapes and some other error reading the tar tapes.

I can write and read QIC-40 tapes using the SCO UNIX drivers, but cannot
read old tapes written under SCO Xenix.  Ranks alot.  Sure glad I spent
all that time backing up the Xenix system to tape so I could retrieve my
valuable files.
--
Steve Ralston						sralston@srwic.UUCP
235 N Zelta						voice: 316-686-2019
Wichita, KS 67206			..!uunet!ncrlnk!ncrwic!srwic!sralston

karl@naitc.uucp (Karl Denninger) (07/02/90)

In article <6925@scolex.sco.COM> md@sco.COM (Michael Davidson) writes:
>
>bill@twg.UUCP (Bill Irwin) writes:
>>The sould of this when I heard it was so absurd I just had to ask the net
>>right  away.   We are just installing an Archive Viper 150Mb  tape  drive
>>into  an i386 running SCO UNIX (current release).  One of the technicians
>>said  that  it could read 60Mb tapes produced on a 60Mb streamer, but  it
>>couldn't produce tapes that could be read by the 60Mb.
>
>I'm afraid that your technician is absolutely right....
>A 150 Meg drive will ONLY write 150 Meg tapes.
>The 150 Meg drives are *supposed* to be able to read 60 Meg
>tapes, but "your mileage may vary" on this one so be sure to
>check this out with some sample 60 Meg tapes written on the
>60 Meg drives that you actually care about BEFORE you
>get yourself into a dire emergency when you actually
>need to read 60 Meg tapes.

Incorrect.

150MB drives will (all, from my experience):
1) read 60MB tapes
2) Read and Write 120MB and 150MB tapes (the difference is in the TAPE; the
   drive senses the distance between the start-of-tape holes to determine
   the density and length). 

This has been true with both QIC02 and SCSI interface units on ISC.  If SCO
doesn't support this then they've gone way out of their way to break it,
since you don't have to do anything special with any other system I've ever
used to make this work (including Suns).

--
Karl Denninger
karl@kbox.naitc.com
(708) 317-3285

gary@sci34hub.UUCP (Gary Heston) (07/03/90)

In article <212@twg.UUCP> bill@twg.UUCP (Bill Irwin) writes:
>The sould of this when I heard it was so absurd I just had to ask the net
>right  away.   We are just installing an Archive Viper 150Mb  tape  drive
>into  an i386 running SCO UNIX (current release).  One of the technicians
>said  that  it could read 60Mb tapes produced on a 60Mb streamer, but  it
>couldn't produce tapes that could be read by the 60Mb.

I don't consider it absurd, and this behavior isn't limited to Archive
products. Tandberg 3660s' are only readable on other 3660s (they're SCSI
150MB drives), but it can read tapes written on 3640s (120MB) or 3620s
(60MB). A tape from a 3620 can be read on any of them, and a tape from
a 3640 can be read on a 3640 or 3660.

Reportedly, we've got a few 3660s with special firmware that allow
them to write on the older tapes, but it's still not readable by
the older drives. The 150MB drives (other than those specials) use
150MB tapes, written at 150MB density. Older drives can't read them.

>I'll  be  digging  into the manual when I get into the office  after  the
>weekend,  but  I thought I would throw this out now because I can't  wait
>for the answer.

Ok... Wangteks work the same way, also. I don't have any experience 
with other drives, but backward read compatability seems to be the 
way the industry is going. I don't know how I'd tell a tape drive 
that I wanted it to cut it's write density by 60% or so...

-- 
    Gary Heston     { uunet!sci34hub!gary  }    System Mismanager
   SCI Technology, Inc.  OEM Products Department  (i.e., computers)
"The esteemed gentleman says I called him a liar. That's true, and I
regret it." Retief, a character created by Keith Laumer.

md@sco.COM (Michael Davidson) (07/04/90)

karl@naitc.uucp (Karl Denninger) writes:

>In article <6925@scolex.sco.COM> md@sco.COM (Michael Davidson) writes:
>>A 150 Meg drive will ONLY write 150 Meg tapes.
>>The 150 Meg drives are *supposed* to be able to read 60 Meg
>>tapes, but "your mileage may vary" on this one so be sure to
>>check this out with some sample 60 Meg tapes written on the
>>60 Meg drives that you actually care about BEFORE you
>>get yourself into a dire emergency when you actually
>>need to read 60 Meg tapes.

>Incorrect.

>150MB drives will (all, from my experience):
>1) read 60MB tapes
>2) Read and Write 120MB and 150MB tapes (the difference is in the TAPE; the
>   drive senses the distance between the start-of-tape holes to determine
>   the density and length). 

You are correct that the 150 Meg drives will write 120 Meg tapes.

Sorry if I didn't make myself sufficiently clear, but my comments
about checking compatibility when it came to reading 60 Meg tapes
were simply intended as a general warning that it is ALWAYS a good
idea to check that tapes can be read on the particular drive that
you may want to read them on BEFORE you actually need to do it
in an emergency. I was not suggesting that 150 Meg drives cannot
in general read 60 Meg tapes - I was just being very cautious.
(and, yes, I *have* had problems reading some 60 Meg tapes
on some 150 Meg drives)

gsn@sclcig.uucp (Georg Nikodym) (07/05/90)

In article <212@twg.UUCP> bill@twg.UUCP (Bill Irwin) writes:
>The sould of this when I heard it was so absurd I just had to ask the net
>right  away.   We are just installing an Archive Viper 150Mb  tape  drive
>into  an i386 running SCO UNIX (current release).  One of the technicians
>said  that  it could read 60Mb tapes produced on a 60Mb streamer, but  it
>couldn't produce tapes that could be read by the 60Mb.

This is true, the 150MB tape drive can read but CANNOT write 60MB tapes.
I'm not sure, but I understand that this has to do with the (electo-)mech-
anics of the head.
-- 
| Georg S. Nikodym  -  (416) 442-2238                                       |
| Southam Business Information and Communications Group, Don Mills, Ontario |
| gsn@sclcig.UUCP -or- ...!uunet!attcan!telly!moore!sclcig!gsn              |
| "The floggings will continue until morale improves" -Jose Castel-Branco   |