SUMMARY: NO tape drive reads and writes QIC-150 and 60-Meg tapes

From: Elizabeth Schwartz (
Date: Wed Jan 19 1994 - 11:39:40 CST

  I asked whether any tape drives could both read and write 150-Meg and
60-Meg cartridge tapes; I also asked about the names of the different
   Got a couple of very fast responses:
From: Dominic Dunlop <>

Quick answer: no.

Slow answer: 60 meg tapes have fewer and wider tracks than 150
meg ones. Consequently, 60 meg drives have a wider read/write head.
A 150 meg drive can read a 60 meg tape by positioning its narrower
head in the middle of the wide track laid down by a 60 meg drive. But
the narrow head of a 150 meg drive can't magnetize the tape enough for
a 60 meg drive to be able to read it reliably. That's the official
story, anyway. And you're not allowed to see whether it's true or
not, because the firmware on 150 meg drives disallows attempts to
write 60 meg tapes.

From: Eirik Fuller <>

There is no way to write a tape on a QIC-150 drive that's readable by
a QIC-24 drive. In order to write QIC-24 tapes, you need a QIC-24

I think there are at least three different formats that can be written
to a DC600A (600 foot) tape. A QIC-150 tape drive writes 120 megs on
it; I think that's called QIC-120. A QIC-24 tape drive writes 60 megs
on it; I think a QIC-24 can also write QIC-11 to a DC600A, but I'm not
sure how much that fits, and I haven't actually tried it. I know that
a QIC-24 drive can read QIC-11.

Perhaps the second format you're thinking of is QIC-11; it was the
default format on Sun2s.
Thanks also to
Robert Bonomi <>

System Administrator                  Internet:
MACS Dept, UMass/Boston               Phone   : 617-287-6448
100 Morrissey Blvd                    Staccato signals
Boston, MA 02125-3393                      of constant information....

This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:08:54 CDT