SUMMARY: 8mm tape drives

From: Mike McCann (
Date: Wed May 01 1991 - 20:52:07 CDT

Thanks for all the responses to my question on how to get Sun 8mm tape drives to read Delta Micro 8mm tapes.

It seems that the simplest way is to use either Sun (st) drivers or Delta Micro (smt) drivers for both tape drives.

Here is an interesting posting from at Delta Micro.
Hope it helps some of you with questions.

----- Begin Included Message -----

The problem you are experiencing with going from the Delta drive to the
Sun's has to do with the mode the drive is in when we write the tape.
The Exabyte drive is capable of three different block-size modes:
1024-byte, 512-byte, and variable. There are switches that allow a
vendor (or customer, for that matter) to select between two of these
modes: 1024-byte and variable as the default for the drive to come up
in at power up. The setting of these switches can be overridden in

Most vendors leave the "Come up" switches set to the Exabyte default of
variable. Delta not only changes this to 1024-byte, but also overrides
this setting depending on the device name you use to access the drive.
When you use our driver you have a choice of three names (actually six
if you count the non-rewind device derivatives). The three basic names
are listed in the following table and cause a different block size to
be used in accessing the drive.

        Device name Mode
        ------------------- -------------------
        /dev/[n]rsmt[0-3] 1024-byte
        /dev/[n]srsmt[0-3] 512-byte (`s' stands for short)
        /dev/[n]vrsmt[0-3] Variable

Sun, along with most other vendors leave the switch set to variable,
and have no functions in the driver that can change mode. This means
that if you want to switch tapes between the Delta driver and the Sun
driver, you must use the /dev/[n]vrsmt[0-3] device name. This will
cause the tape to be written using the variable record size, and thus
be readable by Sun's driver.

I hope this clears up any questions you might have regarding this
issue, but if questions remain, please don't hesitate to contact our
Customer Support department. The number is 415/449-6881. Ask for
Customer Support.

--Mark Galbraith Voice: +1 415 449 6881--
--Software Engineer UUCP: uunet!deltam!mark--
--System Administrator/Postmaster Domain:
--Delta Microsystems, Inc. Compuserve: 76234,3126--

----- End Included Message -----

This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:06:13 CDT