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Date:      Fri, 19 May 2000 19:58:25 -0400
From:      "Michel Joly de Lotbiniere" <Michel@Lotbiniere.Net>
To:        <>
Subject:   Q: Sony AIT-2 SDX-500C tape drive supported?
Message-ID:  <000001bfc1ee$1f366920$>

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Dear Gurus,

I'm debating the use of FreeBSD 4.0 (RELEASE version); due to the fact that
my machine's disk space is entirely occupied by Windows 2K, testing FBSD is
an all-or-nothing proposition, hence I'd like to be fairly certain that this
hardware will work with the usual dump/restore utilities.

This Sony drive is an AIT-2 Internal Tape Drive, OEM Model with Single
Ended, Ultra SCSI, LVDS Interface (see

In the tech ref manual (, p.
173, Sony says "In default configuration, the Sony SDX-500C emulates DDS
drives. In this mode, it supports up to two partitions, logically numbered 0
and 1, where the logical Partition 1 is the first physical partition on the
tape. The physical partition numbering is the same in either the DDS
emulation or the native AIT mode: the first partition on tape is given the
physical partition number of 0. In the DDS emulation mode, the drive
translates the physical partition numbering scheme into the logical scheme
that is communicated to the host. In the AIT mode, the logical partition
numbers correspond directly to the physical partition numbers. SDX-500C
manages DDS Emulation transparently, and it can be used as a large capacity
and a high transfer rate DDS drive." And p. 181 goes on: "Consequently,
SDX-500C can be used with DDS applications without requiring configuration
adjustments via special commands or hardware switches. [...] (1) Cassette
has its own Mode, of which there are two: (a) DDS mode and (b) AIT mode. The
default mode for the drive is also the DDS mode, therefore a MIC cassette
will be initialised as DDS mode cassette. You can initialise MIC in the AIT
mode by using Mode Select Page 31h before Mode Select Page 11h. (2) The Mode
is assigned for the cassette when it is initialised by using Mode Select
Page 11h. If the AIT bit is set to ONE with Mode Select Page 31h before Mode
Select Page 11h, then the cassette will be initialised in the AIT mode. (3)
The power up default mode for SDX-500C is the DDS mode. SDX-500C
automatically changes its mode to the same mode as with the cassette; it
also automatically returns to the default (DDS) mode after ejecting the AIT
mode cassette."

Would this mean /unequivocally/ that the tape drivers in FBSD-4.0-RELEASE
will work happily with this (wonderfully fast) device? The tech manual is a
very detailed description of exactly how the SCSI interface works, but
unfortunately I don't have the required SCSI guru knowledge to deduce the

Any help much appreciated and will be acknowledged.

// Michel Joly de Lotbinière

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