Which Tape Drive to Buy?

Quarter-Inch Cartridge (QIC) | O-MaSS | Minicartridge | DLTtape | Super DTLtape (SDLT) | Linear Tape-Open (LTO) | Half-Inch Cartridge | StorageTek 9840/T9840B/T9940

Helical-Scan Technologies | 4-mm Helical Scan Digital Audio Tape/Digital Data Storage (DAT/DDS) | 8-mm Helical Scan | Mammoth Technology | VXA Technology

Advanced Intelligent Tape (AIT) Technology | S-AIT

Technology Basics
Mainstream tape technologies are aligned within two camps-linear and helical-scan recording. The
debate over which technology is better suited to safeguard an organization's valuable data assets usually
centers on reliability, compatibility, capacity and performance. Each technology claims advantages over
the other in each of these critical metrics, when in fact both technologies are well suited to meet the
requirements of a majority of computing environments.

Linear Technologies
Linear tape-recording technology has been in use since the early stages of computing. Initially it was used
as a primary data storage medium. As storage requirements changed, however, it was replaced in this
role by hard disk drives, which provided the advantage of random access capability. Linear tape then
began to be marketed as a secondary storage medium. Over the years, linear tape technology has
evolved in all key areas-capacity, performance, reliability and cost-and remains the leading secondary
storage device for today's computing environments.

Quarter-Inch Cartridge (QIC)
Quarter-inch tape technology was introduced more than 25 years ago, and although market share has
declined in favor of new formats that yield higher capacity and performance, QIC still accounts for a large
installed base of primarily smaller networked and stand-alone environments. The format has evolved into
higher-capacity implementations and has established standards for backward compatibility that have kept
the technology alive.
QIC tape drives use media that is 0.25 inch or 0.315 inch wide with varying lengths. The widening and
lengthening of the tape were the developments that contributed to moving the technology to new
capacities. Data is recorded in a linear serpentine fashion along parallel tracks that run the length of the
tape. QIC tape cartridges contain two reels, one for tape supply and the other for tape take-up. The
mechanism that drives the reels as well as the tape guide path is internal to the removable cartridge.
Tandberg Data became the sole drive manufacturer in this segment in 1988 with its Scalable Linear
Recording (SLR) technology, which the company continues to develop for smaller or cost-sensitive
computing environments. With the introduction of the SLR100 in November of 1999, Tandberg Data laid
the foundation for its third generation of SLR tape technology. The newer drives-the SLR7, SLR60 and
SLR100-share a common hardware platform, allowing SLR technology to scale in both capacity and
performance while maintaining backward compatibility. Some of their common features include:
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Read Channel-The SLR7, SLR60 and SLR100 drives use a Partial Response Maximum Likelihood
(PRML) read channel and Variable Rate Randomizer (VR2) technology. Tandberg Data and
Overland Data announced a cross-licensing agreement in April 1998 that made Tandberg the first
company to license Overland's VR2, which is a Partial Response Maximum Likelihood (PRML) data-
encoding technology for linear tape drives designed to increase the capacity and performance of a
product or technology by a factor of 1.5 to two times.
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Multi-Channel Thin-Film Magneto-Resistive Head (TFMR)-The SLR100 and SLR60 both use a six-
channel TFMR head. The SLR7 supports a two-channel TFMR head that writes two tracks at the
same time. The use of TFMR head technology, coupled with VR2 encoding techniques, doubles the
tape capacity when compared with previous-generation SLR drives.

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Dedicated Servo Tracking-The SLR100 and SLR60 utilize a servo-based track-following system.
The dynamic real-time servo tracking allows the drive to reliably record and recover data at high track
densities.
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Auto-Sense-The SLR100 and SLR60 support auto-sense features that assist in performance
optimization. Auto-sense will automatically adjust the drive's speed based on the average data
transfer rate from the host to the drive's buffer. Optimizing the transfer rate helps to keep the drive's
data buffer full and the tape moving at a constant speed, thus minimizing the number of times that the
drive must stop and reposition itself before resuming read/write operations. In those instances when
the data transfer speed from the host does fall below the minimum transfer rate for the drive, the
drive will empty its buffer while quickly repositioning itself at the same time so it is ready to resume
write operations once the host fills the drive's buffer.
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In-Line Data Compression-Data compression technology used in Tandberg's SLR drives is based
on the ALDC (Adaptive Lossless Data Compression) algorithm. The SLR100, SLR60 and SLR7 all
support an updated compression scheme called in-line compression, which allows data to be
compressed before entering the drive's 8MB buffer, thereby minimizing backup and restore times. By
using a separate data compression path, 100 percent of the drive's buffer can be used for storing
data prior to being written to tape.
These core technologies will allow SLR technology the ability to cover a broad range of backup
requirements and price points using highly reliable and cost-effective technology, including the potential to
develop SLR drives with native capacities reaching 200GB. Tandberg Data also offers an entry-level SLR
product line targeted at low-end workstations (with native capacities ranging from 525MB to 4.0GB).

O-MaSS
In addition to SLR technology, Tandberg is also developing a new product based on a technology it calls
O-MaSS. This new technology uses a matrix array write head, which Tandberg has been developing for
seven years, that enables writing much-denser data and recording 32 tracks at a time. It uses an optical
servo system and an optical read head. The intent is to use standard media that is available today that will
be housed in a half-inch cartridge similar to that of LTO and DLT. But the tape will be shorter and wider
with a width of 2.5 to 3 inches. It uses a center-park, dual-reel design to provide fast access times, and
the tape reels are oriented horizontally inside the cartridge. It is also unique in that the tape never leaves
the cartridge and the recording head goes inside the cartridge during a read or write operation.
With expected introduction in 4Q03, a first-generation implementation is projected to store up to 600GB of
uncompressed data on a single O-MaSS data cartridge at data transfer rates up to 64 MB/sec. O-MaSS
pricing is expected to be comparable to LTO Ultrium and Super DLTtape at product introduction. The
company also claims that the O-MaSS technology could be used by other tape technologies to boost their
capacity and performance beyond those shown on their current road maps.

Minicartridge
Drives in this category are based primarily on Imation's Travan technology and Advanced Digital
Recording (ADR) technology from OnStream Data. Imation Corporation introduced Travan in 1995 and
currently partners with Seagate Removable Storage Solutions (RSS) to develop drives based on this
technology. OnStream's technology has its foundation in the Philips Digital Compact Cassette (DCC)
audio tape player, which Phillips originally brought to market in 1993. ADR was created by leveraging the
DCC technology along with other research and development that was done by Philips Electronics.

Travan technology, which is based on linear recording technology, is closely related to quarter-inch
standards. It leveraged proven minicartridge technology that existed prior to its introduction in December
1994, and it maintained backward compatibility with the installed base of drives. But it did represent a
major advancement in the technology because it was based on a unique drive/cartridge interface
developed by 3M. At the heart of the new technology was a new-shaped cartridge that optimized the
amount of tape area for cartridges that could fit in a 3.5-inch form factor tape drive. Data is recorded along
the length of the tape with a static read/write head, and drives use single-channel recording and a simple
tape path with only two moving parts in the drive. Unique to Travan drives is the track-positioning system
with prerecorded servo patterns at both ends of the tape. Through accurate electronic servo signal
detection and digital signal processing, the track-positioning algorithm positions the head to the optimal
location relative to the data tracks on the tape. When the read/write head is correctly positioned at the
beginning of the tape, it is locked into position. A precision tape guidance system built into the Travan
data cartridge prevents the tape from wandering.
Seagate and Imation remain committed to extending Travan technology capacity and performance, and in
March 2002 the two companies announced the availability of a new family of sixth-generation Travan
drives, called Travan 40. This new technology extends the native storage capacity to 20GB (40GB with
2:1 data compression) with a native data transfer rate of 2 MB/sec (4 MB/sec when operating in
compressed mode) while maintaining backward read compatibility with 10GB (native) Travan 20 drives.
The Travan 40 uses Seagate's FastSense technology, which adjusts the speed of the tape drive to match
system throughput. FastSense keeps the tape in a streaming mode of operation, helping to optimize
backup times. A number of other design enhancements were also added to the Travan 40, including a
steel frame for improved durability, a soft-load mechanism to reduce normal wear and tear, and a thermal
monitor that activates firmware throttle-down features when drive temperatures reach perdetermined
levels. A VR2 data channel was also incorporated to enable higher recording densities, and a park feature
that ensures the alignment of recording tracks if a write operation is suspended was added.
OnStream's ADR is based on a variable-speed, digital tape storage technology with two distinguishing
features that differentiate it from competitive technologies.
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Spatially Distributed Error Correction Code (ECC)-ADR makes use of spatially distributed ECC,
meaning that error correction bits are recorded over all eight tracks simultaneously so information can
be recovered even if an entire track is lost. OnStream rates the drive error rate at one lost bit in every
1,019 bits written.
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Full Tape Servo-An advanced embedded servo system contributes to high data reliability in two
ways: first by communicating with the head to assure media integrity as it writes data, and second by
preventing the tape from wandering off track, which could make the data unreadable in the future.
OnStream's second-generation ADR drive, the ADR2 120Si, uses a SCSI-3 LVD/SE Ultra-2 compatible
interface and is positioned for use with entry-level servers and workstations. It supports 60GB of native
capacity (120GB with compression) and data transfer rates up to 4 MB/sec (8 MB/sec with 2:1
compression).

DLTtape
Digital linear tape is an adaptation of the early generation reel-to-reel magnetic tape recording method.
Developed by Digital Equipment and originally used in support of its own computer systems, half-inch
DLTtape drives were introduced to the client/server and network-attached PC market several years ago.
Quantum Corporation now owns the DLTtape trademark, having acquired the technology from Digital in
1994. In October of 1998, Quantum and Tandberg Data entered into a strategic manufacturing and

distribution agreement that made Tandberg Data an independent second source for DLTtape drives under
the Tandberg Data brand name, though the specifications remain the same. In October of 2001,
Tandberg Data extended its manufacturing and distribution agreement with Quantum Corporation. The
new agreement allows Tandberg to sell DLTtape and Super DLTtape technology to distributors and
OEMs that are headquartered in Europe, Asia/Pacific and Japan only while U.S. and Latin American
markets would be left to Quantum.
DLTtape products use a single-reel design whereby the tape cartridge contains the supply reel and the
corresponding take-up reel is located in the tape drive. Loading the tape is accomplished by attaching a
leader strip to the end of the tape and using that to pull the tape out of the cartridge, around the head
guide assembly, past a stationary read/write head and onto the take-up reel. This is in contrast to helical-
scan designs, which have two reels per cartridge and rotating read/write heads. The head guide assembly
is shaped like a boomerang and features six rollers that guide the tape along the tape path, working from
the back of the tape so that they never touch the recorded side of the media.
One disadvantage affecting some of the DLTtape drives is the result of the leader mechanism designed to
pull the tape out of the cartridge and wrap it around the take-up reel. Under certain conditions, the leader
can disengage, leaving the tape drawn partway out of the cartridge but not successfully engaged in the
drive. This renders the drive unusable and the tape (with all its data) not repairable. Quantum addressed
this intermittent problem in a revision to its DLT 8000 product by expanding the leader latch to allow more
room for airflow; however, previous models (DLT 4000 and DLT 7000) were not refitted. Both the DLT
4000 and the DLT 7000 have been marked for end-of-life by Quantum. The phaseout for the DLT 4000
was completed at the end of the third quarter of 2001. Quantum, however, has opted to continue selling
the DLT 7000 on a limited basis.
Quantum and Benchmark Tape Systems have engaged in a partnership that allows Quantum to focus its
development initiatives on SuperDLT enhancements, while Benchmark focuses its efforts on improving
and extending the life of DLTtape. Through a technology licensing agreement with Quantum, Benchmark
has developed what is essentially a next-generation DLT 4000, called the DLT1. The DLT1 is replacing
the DLT 4000 and DLT 7000 in the market. DLT1 actually surpasses both products in native capacity with
40GB (the DLT 4000 supports up to 20GB, and the DLT 7000 supports up to 35GB) and in fact actually
matches the DLT 8000. The DLT1 falls in between the DLT 4000 and the DLT 7000 in data transfer rate
at 3 MB/sec native data transfer rate vs. 1.5 MB/sec for the DLT 4000 and 5 MB/sec for the DLT 7000.
DLT1 is read-compatible with the DLT 4000 and utilizes DLTtape IV media. Quantum's Super DLTtape
drive will also read media written by Benchmark's DLT1 tape drive. Benchmark's ValuSmart Tape 80 is a
repackaged DLT1 drive in a half-high form factor. All capacity, performance, format, reliability and
compatibility specifications are identical with the DLT1.
In June 2002, Benchmark announced its next-generation drive in the ValuSmart family, the ValuSmart
Tape 160. The new drive, which is expected to become generally available by year-end 2002, will offer an
80GB native (160GB compressed) capacity and an 8 MB/sec native (16 MB/sec compressed) data
transfer rate, and will be backward read compatible with the DLT1 and ValuSmart 80.

Super DLTtape (SDLT)
The latest generation of DLTtape, called Super DLTtape or SDLT, is based on Laser-Guided Magnetic-
Recording (LGMR) technology, Quantum's name for a conglomeration of features that together facilitate
the increased track density and capacity achieved with SDLT. This technology consists of five elements.
The first is the Magneto-Resistive Cluster (MRC) heads, a group of small magneto-resistive heads that
are packed together to form a cluster and are held in position using thin-film processing technology.

Because the read and write heads are closer together, the clusters are smaller than previous head
configurations.
Second is SDLT's servo system-referred to as the Pivoting Optical Servo (POS)-an optically encoded
servo system on the back of the media that frees up the front magnetic side of the media to hold more
data tracks. As the tape media moves through the POS, the optical tracking laser follows the servo tracks
on the back of the media, tracking the embedded optical targets. The POS assembly pivots around a
single mounting point to keep the read/write heads aligned with the optical servo tracks and reading from
or writing to the tape. This method also allows SDLT media to be bulk erased without losing the
embedded servo tracks.
Third is advanced Partial Response Maximum Likelihood (PRML), which Quantum developed for Super
DLT in conjunction with Lucent Technologies. Advanced PRML is based on technology commonly used in
hard disk drives that allows for higher encoding efficiencies and recording densities, increasing capacity
and transfer rates. Advanced PRML offers peak detect sampling that allows Quantum to put data closer
together on the tracks.
Fourth is the media itself. The SDLT drives use Advanced Metal Powder (AMP) media, which has a
special coating on the back that allows optical servo tracks to be located there. Data capacities are
increased because the entire front side of the tape is available for data tracks. Furthermore, the AMP
media does not require pre-formatting.
Fifth is Quantum's Positive Engagement Tape Leader Buckling System. The company replaced the
previous leader latching mechanism, used on the DLTtape line, with a new design called the Positive
Buckle Link. The Positive Buckle Link uses a solid metal pin on the drive leader that hooks into molded
clips attached to the tape leader inside the cartridge. This is different from the DLTtape design, which
incorporates a hoop at the beginning of the tape cartridge that mates with a "mushroom" on the drive
take-up reel to pull the tape out of the cartridge, through the tape path, and onto the take-up reel. To
support backward read compatibility to the previous-generation DLT products, however, the Positive
Engagement Tape Leader Buckling System also has a "mushroom" to enable SDLT drives to load and
read DLTtape IV media. Quantum expects this design to be even more reliable, especially in highly
automated environments.
Super DLTtape is intended to be scalable and will support a range of products targeted at different market
segments. The industry's first SDLT drive, the Quantum SDLT 220, is targeted at midrange markets,
including large corporate departments and midsize automated libraries, supporting a native capacity of
110GB (220GB compressed with a 2:1 data compression ratio) and a native transfer rate of 11 MB/sec. It
comes in both backward read-compatible and nonbackward read-compatible models. Quantum's follow-
on product to the SDLT 220, the SDLT 320, was released in June 2002 and takes Super DLTtape
technology to the next level on Quantum's Super DLTtape product roadmap. It features a native capacity
of 160GB (320GB with 2:1 compression) and a native transfer rate of 16 MB/sec or 32 MB/sec
compressed. The SDLT 320 is backward read and write compatible with the SDLT 220 and backward
read compatible with previous DLTtape models.

Linear Tape-Open (LTO)
Linear Tape-Open (LTO) is an open tape architecture that was developed jointly by a consortium of three
vendors-IBM, Hewlett-Packard and Seagate. It is made up of two specifications, LTO Ultrium, which was
targeted for capacity-intensive applications, and LTO Accelis, which was designed for access-intensive
applications. Since no manufacturer committed to develop a first-generation Accelis-based product,
however, second-generation licenses were not released, essentially shelving the Accelis specification.

In contrast, the Ultrium specification was pursued by each of the three vendors, all of which currently offer
drives based on first-generation specification. First-generation LTO Ultrium drives support a native
capacity of 100GB (200GB compressed with a 2:1 data compression ratio) and native sustained transfer
rates up to 20 MB/sec (40 MB/sec compressed). Ultrium uses half-inch-wide, Metal Particle (MP) tape, a
multichannel and bidirectional format using a linear serpentine recording method, and Magneto-Resistive
(MR) head and servo technology. Other features common to all first-generation LTO Ultrium drives are:
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Recording Format-LTO Ultrium tapes have 384 tracks recorded in four bands (96 tracks each)
across the half-inch tape. Five servo tracks are prerecorded onto the media to act as guides for the
heads during reading and writing functions. In addition, the LTO media has horizontal servo tracks
that travel down the length of the tape to maintain and control the positioning of the read/write heads
on the data track. First-generation Ultrium tape drives feature eight read/write channels.
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LTO Cartridge Memory (LTO-CM)-All Ultrium tape drives come with LTO Cartridge Memory (LTO-
CM), a radio frequency (RF)-based feature that allows certain kinds of data to be stored on a chip
rather than in the first region of the tape. As a result, the information is accessible as soon as the
cartridge is loaded into the drive rather than when the tape is actually threaded past the head and
read. The types of data that can be stored in LTO-CM include information on the tape contents (such
as file location data), information from the tape manufacturer (such as serial number, manufacturer ID
number and maximum tape speed) and information from the tape drive manufacturer (such as
predictive failure analysis data and information on drive/media health). In all cases, the chip is located
in the rear of the Ultrium data or cleaning cartridge where it can be easily read through an RF
interface by either a stand-alone drive or a reader located on the robotics of a tape library. Data in the
LTO-CM is protected with parity and CRC.
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Interchangeability of Media-Because of the open specification, all Ultrium drives support any
Ultrium-certified media cartridge regardless of manufacturer. In April 2002, the three LTO technology
provider companies (HP, IBM and Seagate) announced that a "universal" cleaning cartridge for
Generation 1 LTO drives is now available from various suppliers allowing end-users to purchase a
single cleaning cartridge for use with all Generation 1 Ultrium drives regardless of the manufacturer.
The LTO Ultrium format was developed from scratch, with no requirements for backward compatibility.
But while the specification was designed to ensure interoperability, it did not mandate such things as drive
form factor, drive interface, power consumption, reliability standards or specific tape path designs. Each
drive/media manufacturer was therefore able to determine how to meet the specification requirements on
its own, thus allowing for design ingenuity and competitive differentiation.
In April 2002, licenses for the second-generation Ultrium format were made available. This initiates the
product development cycle for next-generation Ultrium drives which will support a native capacity up to
200GB using a new second-generation data cartridge. Performance will also improve with native data
transfer rates up to 40 MB/sec. The Generation 2 Ultrium specification also calls for an increase in the
number of tracks, a faster average tape speed, and a more efficient recording method. Ultrium Generation
2 drives will be able to read from and write to a Generation 1 cartridge in Generation 1 format, as well as
Generation 2 cartridges in Generation 2 format. Availability of the second-generation Ultrium drives from
all vendors is expected in early 2003.
The LTO consortium's roadmap includes four generations of Ultrium products that double in both capacity
and data transfer rate with each successive generation. By the fourth generation, Ultrium products are
expected to offer 800GB of native formatted storage capacity and a 160 MB/sec native data transfer rate.
For more information on LTO Technology, see LTO Tape Technology Overview.

Half Inch Cartridge
IBM 3480/3490/3490E
IBM is responsible for several of the half-inch tape technologies that have developed into de-facto
standards within enterprise data centers. Introduced as a successor to 9-track, IBM's 3480 tape drive
revolutionized data center storage in its time with its use of half-inch media contained within a four-inch
square cartridge. The change from first generation tape reels to tape cartridges was the enabling
technology that set the stage for the development of automated backup devices such as autoloaders and
libraries. The 3480 was the drive used in the early development of tape automation robotics and its form
factor remains the standard for high-end enterprise storage today.
The first 3480 tape drive was introduced in 1984 with a storage capacity of 200MB using 18-track
recording and a 3 MB/sec data transfer rate. Five years later, IBM introduced the 3490 tape drive adding
IDRC hardware compression, which increased storage capacity to 1GB depending on data. The final
generation of 3480 technology, the 3490E, increased the number of recording tracks to 36 and added a
double length tape. The 3490E supports a standard length cartridge with a capacity of 400MB (1.2GB
compressed) and an extended length cartridge with a native capacity of 800MB (2.4GB using data
compression). The 3490E supports a channel data rate of 9 MB/sec. The 3480, 3490 and 3490E all use
the same physical size cartridge and are backward compatible.
IBM 3590B/3590E/3590H
IBM introduced its first generation 3590 tape technology in 1995 in conjunction with media supplier 3M.
The 3590 leveraged many of the 3490E mechanical components while adding the latest advances in
recording technology. The 3590 established a basis for a new extendable tape drive family for use in a
broad range of computing environments.
The latest 3590 drive, the 3590 Model H, was introduced in July 2002 with increases in both capacity and
reliability. The Model H uses a 384-track magnetic recording head versus 256 tracks on the Model E and
128 tracks on the Model B. The 3590 Model E drive can read both 128 and 256 tracks and write 256
tracks to existing cartridges, while the new Model H drive can read both 128 and 256 tracks and write 384
tracks to existing cartridges. The 3590 tape drive uses a bidirectional longitudinal serpentine recording
technique as well as a magneto-resistive head that reads and writes 16 data tracks concurrently.
Using a standard length tape cartridge, the 3590 Model H has a native capacity of 30GB. On the Model E,
it is 20GB and on the Model B it is 10GB. With an extended length cartridge, native capacity doubles to
60GB on the Model H, 40GB on the Model E, and 20GB on the Model B tape drives. The 3590 uses the
IBM LZ1 compression algorithm, which is based on the Lempel-Ziv algorithm and Jackson's class of
encoding methods. The Lempel-Ziv (LZ1) data compression technique provides a compressed capacity
up to 90GB on Model H tape drives, 60GB on Model E tape drives, and 30GB on Model B tape drives
using a standard length tape cartridge (assumes 3:1 compression and compressible data). With an
extended length cartridge, compressed capacity goes up to 180GB on the Model H, 120GB on the Model
E and 60GB on the Model B drives.
The 3590 Models E and H provide a native data transfer rate of up to 14 MB/sec. With Ultra SCSI
attachment, 3590 Models E and H are capable of a maximum instantaneous data rate of 40 MB/sec or
sustained data rates of up to 34 MB/sec (assumes 3:1 compression). With native Fibre Channel
attachment, the maximum instantaneous data rate of Models E and H is 100 MB/sec, with sustained data
rates of up to 42 MB/sec (again assuming 3:1 compression). The 3590 Model B supports a 9 MB/sec

native data transfer rate with a sustained data rate of 34 MB/sec in an Ultra SCSI environment. The Model
B drive does not support a Fibre Channel attachment. All 3590 models support ESCON and FICON
attachment using the 3590 A60 Controller, which enables the drives to be shared between ESCON and
FICON servers. Maximum FICON channel link speed is 100 MB/sec full duplex versus ESCON
performance of 17 MB/sec simplex.
The 3590's Metal Particle (MP) tape media is housed in a cartridge that is physically the same size and
shape as the 3480 cartridge design. They are, however, not compatible in any way. They can be used in
the same automation systems (they are physically compatible in terms of robotics handling), but that is all.
The 3590 cartridge case has been designed so that it can be easily detected by a 3590 drive, but a 3590
drive will reject a 3480, 3490, or 3490E cartridge since they do not have the physical characteristics that
are unique to a 3590 cartridge. The leader block of the 3590 cartridge has also been modified so that any
attempt to mount the cartridge in a 3480, 3490 or 3490E drive will be rejected.
A new MP medium with a much higher coercivity is used in the 3590 cartridge. This is required to support
a high aerial density, and the ability to write a large number of tracks. The 3590 was designed for
increased data integrity and uses Error Correction Code (ECC) and servo tracks that are prerecorded at
the time of manufacture for precise head positioning. These tracks enable the 3590 tape drive to position
the read/write head accurately with respect to the media while the tape is in motion. Additional reliability
features include resident diagnostics that dynamically monitor drive and media performance to detect
potential problems and preemptively aid in resolution. The 3590 also provides redundant data protection
capabilities. By systematically disbursing data across the media as it is written with redundant parity
checking bits, there is a reduced chance of information loss should a media error occur.

StorageTek 9840/T9840B/T9940
The StorageTek 9840 is a high-performance tape drive with relatively low storage capacity, targeted at
applications that require extremely fast data access and "disklike," random-retrieval operations. With the
9840, StorageTek introduced a new class of data center drives capable of spanning multiple
environments, ranging from MVS and OS/400 to Unix and Windows NT/Windows 2000. The 9840
cartridge matches the 3480 form factor and can be mixed and matched with 3480 class drives in the
same StorageTek tape library.
StorageTek embarked on the original 9840 design in order to accomplish new levels of performance that
were not available in half-inch tape technology at the time. Fundamental to the 9840's performance is its
use of a dual-reel cartridge and self-contained tape path, all incorporated within a 3480/3490-shaped
cartridge. By encasing the critical tape guidance, movement and head/tape interface mechanisms within
the cartridge, the 9840 eliminates the need to thread up the tape within the transport. The drive is ready
for operation as soon as the cartridge is loaded into the transport and locked into position. The 9840
cartridge design also leads to improved reliability, since the tape never leaves the cartridge enclosure,
reducing problems that may result from head/media misalignment. The 9840 automatically loads at the
midpoint of the tape, essentially halving the search time to the end of tape and resulting in superb data
access speeds during restore operations. Before unloading, the 9840 repositions the tape to its midpoint
location for future use.
In October 2001, StorageTek introduced a new second-generation 9840 drive called the T9840B. The
T9840B boosts performance over the first-generation 9840, but with no increase in capacity. Both T9840B
and 9840 have a native storage capacity of 20GB, and their use of enhanced LZ-1 data compression
technology allows compressed capacities of typically 80GB using a 4:1 compression ratio in MVS/ESCON
mainframe environments. In open-system environments running Unix or Windows NT/2000 on SCSI or
fiber, 2:1 compression ratio is common, providing capacities up to 40GB. The T9840B supports a native

data transfer rate of 19 MB/sec, nearly two times the original 9840's 10 MB/sec native data transfer rate.
This is primarily the result of a doubling of tape speed during read/write operations from 79 inches/second
on the 9840 to 158 inches/second on the T9840B. Tape speed during rewind and search operations
remains the same for both drives at 315 inches/second. The size of the T9840B's data buffer has been
increased to 32MB from 8MB on the 9840, further improving drive performance. The maximum internal
data transfer rate of the T9840B has been increased to 70 MB/sec from the 9840's maximum internal
throughput of 40 MB/sec, both assuming highly compressible data. This allows the fibre channel version
of the T9840B drive to more fully exploit mainstream 100 MB/sec fibre channel connections. The T9840B
has also been designed with a 2-Gigabit fibre channel controller interface protecting a customer's
investment by providing a growth path into 200 MB/sec fibre channel storage area network (SAN)
infrastructures. With 2:1 compression, the T9840B can therefore achieve data transfer rates approaching
40 MB/sec using an Ultra SCSI interface in an open systems environment.
The T9940 is StorageTek's "capacity-centric" solution, geared toward environments that require the same
robustness as the T9840B and 9840, but where the customer is willing to trade off data access time to get
greater storage capacity. StorageTek's T9940 tape drive is based on first-generation 9840 technology and
shares many components with the 9840 drive; however, it delivers a higher storage capacity in exchange
for slower search and data access times. The T9940 supports a native capacity of 60GB and, like its high-
performance counterpart, uses enhanced LZ-1 compression techniques that typically provide 120GB of
compressible data in Unix and Windows NT/2000 operating environments and 240GB in MVS mainframe
environments. The T9940's higher data capacity is achieved by using a single-reel tape cartridge that
holds more tape than the 9840's dual-reel cartridge. Search time and first access to data averages 41
seconds, or approximately five times that of the 9840 tape drive. The T9940's average file access time in
subsequent searches is 30 seconds, assuming a search of 1/3 the tape length. Tape load and initialize
time is 18 seconds, compared with the 9840's four seconds, and its maximum rewind time is 90 seconds,
compared with the 9840's 16 seconds. Connectivity options for the T9940 support both mainframe and
open systems environments using ESCON, Ultra SCSI and fibre-channel interfaces. All other T9940
specifications are identical with the original 9840.

Helical-Scan Technologies
Hewlett-Packard, Sony and Exabyte pioneered the use of helical-scan technology for data backup
applications. By leveraging the mechanisms used in video and audio recorders, the intent was to
capitalize on economies of scale, thus reducing cost and time to market.
Helical-scan tape drives record data on tracks that are written at an angle on the tape rather than parallel
with the tape edge as with linear recording. The read/write heads in helical scan tape drives are mounted
on a spinning drum, which is known as a rotary head. The head is oriented at a slight angle relative to the
tape and contains two read heads and two write heads alternately spaced 90 degrees apart. The tape
moves in the opposite direction to the rotary head, and multiple tracks are recorded and verified
concurrently. Typically, the tape supply and take-up reels are both contained within the cartridge. In most
of these drives, the tape is pulled into the drive and then wrapped partially around the drum. The tape
path is part of the device. Helical-scan tape drives fall into the following categories based on the type of
media or cartridge and the width of the tape.

4-mm Helical Scan Digital Audio Tape/Digital Data Storage (DAT/DDS)
Digital Audio Tape (DAT) was originally developed as a format for consumer audio applications and was
later expanded by Hewlett-Packard and Sony through the Digital Data Storage (DDS) standard so that
DAT drives could be used for reliably storing computer data. Specifications for the current DAT standard,

DDS-4, were developed in 1997 and endorsed by the Digital Data Storage Manufacturers Group, which
consists of industry-leading tape storage organizations.
DDS-4 has a native capacity of 20GB on a single data cartridge (40GB compressed with a 2:1 data
compression ratio) at native backup speeds up to 2.75 MB/sec (5.5 MB/sec compressed). Compared to
the previous DDS-3 DAT standard, that represents a 67 percent increase in capacity and a 150 percent
increase in performance. The increased capacity of DDS-4 is accomplished through a reduction in the
track pitch from 9.1 µm to 6.8 µm, increasing the number of tracks written over 1 mm of tape from 12
tracks to 16. DDS-4 also uses an increased tape length of 155 meters (up from 125 meters). The
increased transfer rate is achieved by improvements in read/write head technology, increased drum
speed, improved channel recording techniques and advances in media technology.
Sony and HP both stated that they would undertake no further development of the 10-year-old DDS
standard beyond the DDS-4 format. Sony will instead replace its DDS line with AIT solutions starting with
the enhanced AIT-1 drive, while HP will cover the space that it traditionally sold DDS with DLT1 products.
Exabyte has also entered the segment and is attempting to lure DDS users with its VXA products that
were acquired in late 2001 through its merger with Ecrix Corporation.

8-mm Helical Scan
Early adaptations of 8-mm tape drives were based on video camcorder technology with modifications for
storing computer data. Today's secondary storage manufacturers now design this class of product
specifically for computer data storage applications. All products in this category record data on 8-mm-wide
media.
There are two main 8-mm-based protocols that encompass all ongoing product development using this
platform. Exabyte was the driving force behind the use of standard 8-mm technology and has evolved the
technology through its proprietary Mammoth and Mammoth-2 developments. Sony and Seagate have
developed the Advanced Intelligent Tape (AIT), which has since evolved into the second-generation AIT-2
format and the third-generation AIT-3 format. Although Mammoth and AIT are both 8-mm technologies,
the two formats are incompatible and cannot share media interchangeably.

Mammoth Technology
Although based on 8-mm helical-scan recording technology, the first-generation MammothTape drives
(Mammoth-LT and Mammoth) incorporated several significant improvements over the original 8-mm
drives that used camcorder-based mechanisms. With Mammoth, an Exabyte-designed and manufactured
industrial-quality deck design was introduced that eliminated the capstan and pinch-roller system. The
capstanless design removed the part of the drive that places the most pressure on the tape media,
causing unpredictable wear and reducing reliability. A larger scanner was added that completely records
the tape from edge to edge, providing higher capacity and data transfer rates. With the introduction of
Mammoth, Exabyte also added an improved tape transport system that supports Advanced Metal
Evaporated (AME) media-an alternative that is cleaner to use and provides greater capacity than Metal
Particle (MP) tape. In addition, Exabyte changed the tape path design to reduce potential stress points on
the tape. Finally, with Mammoth technology came an innovative approach to extending cleaning intervals
through the use of a cleaning wheel called a Dynamic Head Cleaner that reduces the likelihood of head
contamination by briefly touching the scanner and heads whenever a tape is loaded. The Dynamic Head
Cleaner also automatically performs a cleaning after each 80 minutes of continuous tape motion and can
be invoked by the drive's firmware if needed during extended backups.
The second-generation MammothTape drive, Mammoth-2 (M2), has a native formatted capacity of 60GB
(150GB with a 2.5:1 data compression ratio) and a native sustained data transfer rate of 12 MB/sec (30

MB/sec compressed). It includes a 32MB adaptive buffer that works to compensate for any
inconsistencies in data flow from the host. It also uses an enhanced Partial Response Maximum
Likelihood (PRML) data-encoding scheme and Adaptive Lossless Data Compression (ALDC) as its
compression engine, yielding a compression ratio of 2.5:1 for higher capacity. The M2 features a four-
channel/eight-head scanner in contrast to the Mammoth-1 drive, which had a two-channel/four-head
scanner. The additional read/write heads quadruple the tape drive's transfer rate.
The M2 also adds improvements in the area of tape reliability by using a unique three-pronged approach
to keeping the drive clean. First, it features a Dynamic Head Cleaner, the small cloth-covered wheel
described above. Second, the M2 uses a set of inactive burnishing heads to prep the tape before it
reaches the active read/write heads. These "conditioning heads" are intended to make sure that the tape
is set at the correct air bearing and to remove any contaminants from the tape's surface before it passes
over the read/write heads. Third, the M2 utilizes special AME media, which is equipped with Exabyte's
proprietary "SmartClean" technology. This media design includes a section of cleaning material at the
beginning of each recording tape so that the drive can automatically clean itself when necessary.
The M2 was the first helical-scan drive to offer support for native fibre channel connectivity by attaching
directly to the SAN, eliminating the need for fibre channel-to-SCSI routers. M2's one-Gigabit fibre channel
interface allows throughput of up to 100 MB/sec per path. Along with lowered infrastructure costs, this
type of interface allows the M2 to support serverless backup with the extended copy command that is
embedded into M2 firmware, making continuous, 7x24 backup possible. E-copy is Exabyte's
implementation of the SCSI Extended Copy command within the M2 drive and allows the direct transfer of
data between disk and tape. Data can be transferred across the SAN without the intervention of a server,
eliminating a potential bottleneck in the backup process.
Exabyte announced a new market strategy in April 2002 that redirects the development of its third-
generation MammothTape drive, the Mammoth-3 (M3), which was underway. Now that Exabyte has fully
integrated Ecrix Corporation into its operations, the company will attempt to capitalize on its acquired VXA
technology by integrating it with MammothTape and deliver a new set of products that will provide
improved price/performance and reliability. The new Mammoth-3 will offer a compressed capacity of
625GB and a compressed transfer rate of 60 MB/sec. The drive will be available in two versions, one that
will be backward-read compatible with VXA products, and another with additional backward-read
compatibility with M2.

VXA Technology
VXA tape technology was created by Ecrix Corporation, which entered into a merger agreement with
Exabyte in August 2001. As of November 2001, Ecrix's operations were fully integrated with Exabyte and
now operate under the Exabyte name.
Exabyte will continue to focus its VXA technology on the low-cost market segment. The next-generation
VXA-2 became available in June 2002. The VXA-2 drive offers a compressed capacity of 160GB and a
compressed data transfer rate of 12 MB/sec. VXA-2 pricing is expected to be comparable to the VXA-1 at
introduction. The VXA roadmap includes at least two more product generations following VXA-2. The
VXA-3 is projected to support 320GB of compressed capacity at a 16 MB/sec compressed data transfer
rate, while VXA-4 is expected to offer 640GB of compressed capacity at speeds up to 32 MB/sec
compressed.
VXA offers a unique approach to data recording that allows it to address some of the inherent
weaknesses associated with streaming tape technologies. In order for a linear or helical tape drive to
operate at peak efficiency, large blocks of data must be read or written from the drive while the tape is

moving at a constant speed (or "streaming") to keep the drive's data buffer full. When "streaming" is
interrupted, the drive must reverse direction and reposition the tape before read/write operations can
resume.
VXA uses a proprietary data format and algorithms for data verification and correction. Instead of
formatting data on a tape in long strings, which requires the drive to stream for optimum read/write
performance, VXA breaks the long data strings into smaller packets before being recorded on the media.
VXA's Discrete Packet Format (DPF) uses 64 bytes of user data per packet and 387 packets per track.
Data packets also contain a synchronization marker, unique address information, Cyclic Redundancy
Check (CRC) code and Error Correction Code (ECC).
During a read operation, the VXA drive uses all four leading and trailing heads to scan the tape and read
the data packets into a buffer segment. The packets that compose a data string may arrive at different
times in the data buffer. Because each packet has a unique address, the VXA buffer architecture
efficiently reassembles the packets in the correct order, regardless of the order in which they were
received. The VXA data buffer retrieves data with each pass of the read heads until all data packets are
loaded into the buffer.
Much like other streaming tape technologies, VXA does not rely on precise alignment of heads and data
tracks to read or write data reliably. Instead, VXA reads and writes data in packet form and overscans the
recorded area of the tape. Overscanning requires a system architecture that eliminates the dependency
on the alignment geometry between the tape path and the recording head. To read or write data,
streaming tape devices depend on a constant head-to-tape speed for linear recording or a constant track
angle for helical-scan recording. VXA's technique allows each channel of the drive to scan an area
greater than 100 percent of the recorded area of the tape, ensuring a full data recovery and increasing the
reliability of data interchangeability between different VXA drives.
VXA's Variable Speed Operation enables it to continually adjust the tape speed to match the actual data
transfer rate between the drive and the host. Because VXA can vary the speed at which it sends or
receives data, it is unlikely that VXA ever has to stop the motion of the tape completely. In the rare
instance that data transfer operations do stop, the VXA drive can gently slow down to a "Ready Mode"
and then restart from that location when read/write operations resume. By eliminating tape repositioning,
VXA reduces performance degradation as well as wear on the media and drive mechanism, which can
compromise the reliability of the data.
The combination of VXA's Discrete Packet Format, its ability to alter the speed of the tape to match
available host bandwidth and an overscanning technique which allows data to be read from any physical
location on the tape without having to follow a chain of tracks from beginning to end results in a new and
economical backup technology which is fast, reliable and less sensitive to media errors.

Advanced Intelligent Tape (AIT) Technology
Sony produced the first AIT tape drive in 1996 with the goal of doubling capacity and transfer rate every
two years. AIT falls into the 8-mm category, and its cartridge is the same size as other 8-mm tape
cartridges, but its recording method is proprietary and incompatible with 8-mm products from Exabyte. AIT
drives include a cartridge-sensing system to ensure that only cartridges designed for AIT drives are used.
AIT AME media contains a special ID that the drive will recognize. If an AIT AME cartridge is mistakenly
inserted into a non-AIT 8mm drive, a write-protect feature will be activated to protect it from possible data
corruption.
The first-generation AIT format, the AIT-1, supported a native capacity of 25GB (65GB compressed with a
2.6:1 data compression ratio) and a 3 MB/sec native sustained transfer rate (7.8 MB/sec compressed). An

extended-length tape for the AIT-1 drive was later added to increase the maximum native capacity to
35GB (91GB compressed). An AIT-1 enhancement, dubbed the "Valueline" AIT-1, was introduced in
January 2001 and leverages elements of the AIT-2 design to increase the AIT-1 drive's native data
transfer rate to 4 MB/sec (10.4 MB/sec compressed). The Valueline AIT-1 also added an Ultra Wide SCSI
interface, a 10MB data buffer and increased the rotational speed of the drum to 6,400 RPM. It uses a
Partial Response Maximum Likelihood (PRML) data-encoding scheme to support its high linear recording
density of 116,000 bits per inch (bpi). The high compression rate is achieved using a customized and
optimized version of IBM's Adaptive Lossless Data Compression technology (ALDC), which delivers a
2.6:1 data compression ratio, although actual compression efficiency largely depends on data type.
AIT-1 uses a unique head geometry and tension control system which helps to reduce tape tension by as
much as 50 percent when compared with competing technologies. Tape tension is a critical factor in head
and media wear, and AIT's extremely low and carefully controlled tape tension results in a 50,000-hour
head life. Its Auto Tracking Following (ATF) servo system senses and corrects any off-track positioning,
keeping the tape perfectly centered on the read/write head for data accuracy.
Introduced in March 1999, the second-generation AIT drive, AIT-2, provides full backward compatibility
with AIT-1 while doubling the native capacity of the original AIT-1 drive to 50GB (130GB compressed).
The native data transfer rate was likewise doubled to 6 MB/sec (15.6 MB/sec compressed). This doubling
of capacity and speed was accomplished through technological advances in both the drive (recording
heads, channel coding, media formulation and mechanism design) and recording media. AIT-2 also has a
10MB data buffer and uses a Trellis-Coded Partial Response (TCPR) encoding method, which increases
its linear recording density to 167,000 bits per inch. The rotational speed of the AIT-2 drum was increased
from 4,800 RPM to 6,400 RPM. AIT-2 uses Sony's patented HyperMetal laminate heads and an on-drum
amplifier to enhance the signal to the head and reduce noise, thereby minimizing read errors.
AIT drives use an Advanced Metal Evaporated (AME) tape media, which reduces the accumulation of
deposits on the head. AME media is made without nonmagnetic binder materials that can contaminate the
read/write heads or produce other media-related drive errors. AME's Diamond-Like Carbon (DLC)
abrasive resistant coating limits wear on the head and media and eliminates the need for cleaning tapes.
The head itself detects any accumulation of deposits on the head from changes in error rates. When the
head detects deposits, it automatically initiates a self-cleaning process using the built-in head cleaner,
thus eliminating the need to clean the head regularly using a cleaning cartridge.
AIT's key differentiating feature is intelligence embedded into the tape cartridge called Memory-In-
Cassette (MIC). Sony's MIC technology was introduced with the first-generation AIT-1 drive and later
enhanced in the AIT-1 extended-length tape model and on AIT-2. MIC is a 64Kb flash memory chip (16Kb
on SDX1-25C tape media) that is incorporated into the data cartridge and stores various system and user
information directly within the MIC structure to enhance data reliability, error prediction and access
performance. On-chip data includes system logs, search map and user-definable information, allowing
fast access to data anywhere on the tape. Storing key data parameters in nonvolatile memory that is an
integral part of the cartridge rather than on the tape media provides fast access to on-tape structures and
media statistics by any MIC-compatible AIT drive without having to first read the physical tape media. The
MIC detects ID data for the requested information and moves the tape at its rewind speed (122
inches/second on AIT-1 and 160 inches/second on AIT-2) to the approximate location of the data. Then it
slows down to read the ID blocks on the tape to locate the specific data requested. AIT supports an
average data access time of 27 seconds (using a 170m tape), which is more than 2x improvement when
compared with competing technologies. Other tape technologies maintain directory information in a
header area on the tape media itself that must be read each time a tape is loaded and rewritten when any
modifications to data are made. The MIC also supports multiple partitions and load points, which allows

the loading and unloading of a cartridge to occur without having to rewind the tape to the beginning. The
ability to park the tape at any one of the 64 on-tape partitions means that an AIT drive can support a
"midpoint load" (similar to the StorageTek 9840), which would essentially halve the search time to the end
of tape in either direction, resulting in fast data access speeds during restore operations. This assumes
that before unloading a cartridge from the drive, the tape was positioned to its midpoint location for future
use.
Sony's third-generation AIT product, the AIT-3, was made available for sale in November 2001. The AIT-3
doubles the capacity and performance of AIT-2 and is fully backward read and write compatible with all
AIT-2 and AIT-1 media, enabling users to seamlessly migrate to the higher capacity of AIT-3 without
losing access to previously backed-up data. A new 230-meter data cartridge, the SDX3-100C, has been
designed for use with the AIT-3. AIT-3 supports a native capacity of 100GB (260GB with 2.6:1 data
compression) and a native data transfer rate of 12 MB/sec (31.2 MB/sec compressed). The increased
capacity of AIT-3 was achieved by narrowing the track pitch from 11 microns on AIT-1 and AIT-2 to 5.5
microns on AIT-3. The increase in data transfer rate results from a number of factors, including doubling
the number of channels (from two to four), doubling the number of heads (from four to eight),
simultaneously utilizing two recording heads on tape, and the increased area density. The data buffer has
also been increased from 10MB on AIT-1 and AIT-2 to 18MB on AIT-3.
Like the AIT-1 and AIT-2, the AIT-3 is designed in a 3.5-inch form factor. AIT-3 supports an Ultra 160
Wide SCSI LVD/SE interface, allowing it to support up to a 160 MB/sec synchronous burst data transfer
rate, whereas AIT-1 and AIT-2 both use an Ultra Wide SCSI LVD/SE interface with a maximum
synchronous burst data transfer rate of 40 MB/sec. AIT-3 drives incorporate Sony's new Remote-Memory-
In-Cassette (R-MIC) media interface system. The R-MIC enables the drive to access key tape parameters
embedded in the data cartridge without the tape being loaded, improving access time to data. This is a
particularly useful feature for tape automation applications.
Sony continues to maintain its commitment to the AIT roadmap and its design goal of doubling both
capacity and performance every two years for six generations. In doing so, it has provided general
visibility for AIT-4, AIT-5 and AIT-6 capacity and performance, which is in keeping with its design goal.

S-AIT
In November 2001, Sony made a technology announcement indicating its plans to develop a next-
generation AIT format called S-AIT. Like AIT, S-AIT is based on helical scan recording technology. The
new specification will allow for native capacities up to 500GB on a single cartridge, with native data
transfer rates up to 30 MB/sec. With 2.6:1 compression, the first-generation S-AIT drive will be capable of
storing up to 1.3TB of data on a single cartridge at transfer rates up to 78 MB/sec. Like it did with AIT,
Sony has stated its goal of doubling capacity and performance every two years, allowing the S-AIT
architecture to reach native capacities of 4TB and native transfer rates of 240 MB/sec. S-AIT drives will be
housed in a full height 5.25-inch extended drive form factor, whereas existing AIT models use a 3.5-inch
form factor. First-generation S-AIT drives are expected to support Ultra 160 SCSI and fibre channel
interfaces. S-AIT is expected to leverage some of Sony's technology and component research done for
AIT, but will use a 600m single-reel, half-inch tape cartridge housed in a cartridge similar to an LTO or
SDLT cartridge. The form factor of S-AIT drives and its media should allow for quick integration into
existing automation solutions. S-AIT media will include R-MIC technology, which enables fast load times
and data searches. Sony has partnered with Matsushita, a company with expertise in helical-scan product
design and manufacturing, to bring S-AIT to market in the late 2002 or early 2003 time frame.

Tape Automation Products
As data storage capacity requirements increase, the need for higher-capacity tape storage solutions
grows. One way to gain additional capacity and simplify the backup and retrieval process at the same
time is through automation. In fact, today's tape drives are frequently designed with the automation
market in mind, with drive manufacturers working closely with automation vendors to ensure compatibility
before the new drives are even released.
There are two types of automation products for users who need more storage capacity than a single tape
can hold-autoloaders and tape libraries. Autoloaders are single-drive mechanisms that exist in an
enclosure that features a multiple-cartridge magazine and a robotic system to insert and remove the
cartridges from the drive automatically. Tape libraries go a step further with multiple drives and many
more cartridges for even greater storage and faster archival and retrieval.

Technology Analysis
In an industry where the time between a product's launch and its obsolescence can sometimes be
counted in mere months, it is extraordinary that tape drive technology remains such a predominant
component of the storage mix. Tape has been the technology of choice for data backup since the advent
of computing, and continued breakthroughs in drive, media and automation robotics design should help it
maintain its leadership position.
The key to the survival of tape technology may well be the manufacturers' willingness to adapt and evolve
the technologies to the changing needs of the market. Customers expect tape technology providers to
deliver improved capacity and performance on an ongoing basis and at roughly the same cost per
megabyte. Depending on the scalability of the technology, manufacturers may modify a particular design
to deliver improvements in data transfer rates, capacity and reliability. In other instances, a complete new
architecture is required to make the improvements necessary to remain competitive. Exabyte went
through this transition when it moved from its original 8-mm tape drive technology to its first-generation
Mammoth technology and then again as it transitioned to its second-generation Mammoth-2. Likewise,
IBM, Hewlett-Packard and Seagate, through their cooperative design effort, have all gone through a
similar process, resulting in the development and introduction of LTO Ultrium-based products. Quantum
progressed from its DLTtape technology to SDLTtape, which, although it is positioned as the follow-on
product to DLTtape, incorporates a significant number of new technologies as well.
Although the customer's alignment around one camp or the other (linear or helical technologies) has
historically been at the center of the decision criteria, both technologies have evolved over the years, and
many of the negative factors of each one have been addressed.

Business Use
Demand for tape and tape automation products continues to expand in spite of predictions that it is a
technology on the decline. Tape technologies continue to evolve in an effort to meet customer demands
for performance, capacity, scalability and reliability in storage solutions.
As businesses commit more and more of the time that used to be available for backup tasks to around-
the-clock operations, backup windows are rapidly shrinking, and the cost of downtime has increased
significantly. With the advent of such storage management applications as remote copy and snapshot
copy, users now have the ability to make a rapid copy of their data and then utilize tape technology to
back up the data faster than ever. While there is the threat of optical technologies on the horizon, for the
time being tape technologies are holding their own. In 2001, the total industry expenditure for tape drives
of all formats (factory revenue based on worldwide shipments) was approximately US$2.62 billion,
according to Gartner Dataquest figures. That was down from US$3.01 billion in 2000.

Technology Leaders
Leaders in the tape storage market include Benchmark Tape Systems, Exabyte, Hewlett-Packard, IBM,
OnStream Data B.V., Quantum, Seagate Removable Storage Solutions, Sony Electronics, Storage
Technology and Tandberg Data.
Benchmark Tape Systems Corporation (Boulder, Colorado)
Founded in May 1998, Benchmark Tape Systems Corporation develops tape and storage solutions that
are based on standard DLTtape technology licensed from Quantum Corp., a minority investor. In 2001,
Benchmark achieved a 4.6 percent unit market share (3.1 percent based on factory revenue) of the "small
form factor half-inch cartridge/other data cartridge" market segment, according to Gartner Dataquest.
Exabyte Corporation (Boulder, Colorado)
Exabyte was one of the pioneers in 8-mm data storage technology and created both the Mammoth and
the M2 standards as a means of moving the technology into midrange markets. Exabyte also offers a line
of tape automation solutions based on MammothTape, VXA, AIT-2, DLTtape and LTO Ultrium
technologies. In November 2001, Exabyte and Ecrix Corporation completed a merging of operations
operating as a single entity under the name Exabyte. Ecrix pioneered the development of VXA tape
technology, which offers an innovative approach to improving data reliability across all price points.
Hewlett-Packard Corporation (Cupertino, California)
Hewlett-Packard's tape products compete in three market segments-minicartridge, 4-mm helical scan,
and "small form factor half-inch cartridge/other data cartridge" (with its two LTO Ultrium drives). In 2001
the company achieved unit market shares of 3.9 percent for minicartridge, 44.4 percent for 4-mm helical
scan, and 8.4 percent for "small form factor half-inch cartridge/other data cartridge" and factory revenue
market shares of 4.6 percent for minicartridge, 54.2 percent for 4-mm helical scan, and 14.2 percent for
"small form factor half-inch cartridge/other data cartridge," according to figures from Gartner Dataquest.
HP was one of three members of the open architecture LTO consortium that developed the two LTO
specifications, demonstrating its commitment to tape technology by dedicating vast R&D resources to the
new format's development.

IBM (Armonk, New York)
IBM offers products in both the high-end and the low-cost half-inch cartridge market segments, as well as
in the "small form factor half-inch cartridge/other data cartridge" segment (with its Ultrium entry). IBM was
not only one of the three founding members of the LTO open tape architecture consortium, it was also the
first to release a product to market based on the Ultrium specification. According to Dataquest, the
company had a 7.7 percent share of the small form factor half-inch cartridge/other data cartridge market
segment based on units shipped (17.5 percent based on factory revenue) in 2001.

OnStream Data B.V. (Eindhoven, the Netherlands)
OnStream Data B.V. is a new company formed in May of 2001 through the acquisition of intellectual
property and other assets from the former OnStream, Inc., after they ceased operations in March of 2001.
Philips Electronics originally developed OnStream's ADR technology. A sister company, OnStream MST,
manufactures the state of the art thin film heads used in the ADR tape drives manufactured by OnStream
Data. In 2001, OnStream Data achieved a 15.6 percent unit market share (24.7 percent based on factory
revenue) of the minicartridge market segment, according to Dataquest.

Quantum Corporation (Milpitas, California)
According to Dataquest, Quantum, with its line of DLTtape and SDLTtape products, was responsible for
58.7 percent of the unit shipments and 54.8 percent of the factory revenue in the "small form factor half-
inch cartridge/other data cartridge" market segment for 2001.

Seagate Removable Storage Solutions (Costa Mesa, California
Like Hewlett-Packard, Seagate Removable Storage Solutions (RSS) competes in three different market
segments-minicartridge, 4-mm helical scan and "small form factor half-inch cartridge/other data
cartridge" (with its Viper 200 LTO Ultrium drive). In 2001, the company had a 79.9 percent unit market
share (69.8 percent factory revenue market share) in the minicartridge market, a 29.8 percent unit market
share (24.1 percent factory revenue market share) in the 4-mm helical-scan category and a 2.2 percent
unit market share (2.8 percent factory revenue market share) in the "small form factor half-inch
cartridge/other data cartridge" segment, according to Gartner Dataquest. Seagate is the third member of
the LTO open tape architecture consortium and has likewise committed enormous resources to the
development of the new format.

Sony Electronics, Inc. (San Jose, California)
Sony Electronics competes in both the 4-mm helical-scan and the 8-mm helical-scan segments, where,
according to Gartner Dataquest, it achieved market shares of 25.1 percent and 50.4 percent, respectively,
in 2001, based on unit shipments. Looking at market share by factory revenue, Sony had a 21.2 percent
share of the 4-mm helical-scan market and a 48.2 percent share of the 8-mm helical-scan market
segment in 2001. The company, which has been in the tape business for over 50 years, codeveloped the
4-mm DDS tape format and was the sole developer of AIT technology (its 8-mm offering).

Storage Technology Corporation (StorageTek) (Louisville, Colorado)
StorageTek remained the market leader in the high-end, half-inch cartridge segment, with 55.8 percent of
the units shipped and 53 percent of the factory revenue in 2001, according to Gartner Dataquest figures.
In addition, StorageTek is a player in the other helical-scan market, competing primarily with Sony and
Ampex.

Tandberg Data ASA (Oslo, Norway)
Tandberg Data has been the sole manufacturer of quarter-inch data cartridge (QIC) tape drives since
1998, with its tape drives based on SLR technology. Tandberg Data has an exclusive licensing agreement
with Quantum Corporation, which allows it to compete in the "small form factor half-inch cartridge/other
data cartridge" market segment with a line of DLTtape and Super DLTtape drives that it sells to
distributors and OEMs headquartered in Europe, Asia/Pacific and Japan. The agreement calls for
Quantum to focus its efforts on marketing and selling DLTtape and Super DLTtape drives in North
America and Latin America. According to Gartner Dataquest, the company had a 1.8 percent share of the
small form factor half-inch cartridge/other data cartridge market segment based on units shipped (2.0
percent based on factory revenue) in 2001.

Other Tape Drive Vendors
In addition to those named above, there are a number of other vendors who play a role in this market.
They include Ampex (other helical scan), Fujitsu (low-cost and high-end, half-inch cartridges), M4 Data
(low-cost, half-inch cartridge) MKE/Panasonic (4mm helical scan), NEC (high-end, half-inch cartridge),
Overland Data (low-cost, half-inch cartridge) and Victor Data Systems (low-cost, half-inch cartridge).

Insight
The tape market has long been characterized by the vast proliferation of competing technologies available
for use. Whereas users once lauded the flexibility of choice this provided, uncertainty and confusion grew
as the number of options increased. And as overall data capacity needs increase and data availability
requirements move to 7x24 continuous operation, demands to shrink backup windows and reduce restore
or recovery times continue to pressure tape technology manufacturers to deliver the innovative solutions
needed to address these requirements. Today, vendors are working hard to develop ever-faster and
larger-capacity drives while still paying close attention to the issue of backward compatibility in an effort to
retain the loyalty of their respective installed bases.
The introduction of LTO Ultrium and Super DLTtape opened the door for increased competition in the
user's favor as the natural flow of competition works to help keep costs in check. In the helical-scan camp,
the November 2001 introduction of Sony's AIT-3 and the expected introduction of its new S-AIT model by
end of year 2002 continues to put pressure on linear tape technology manufacturers as both sides
compete for end-user as well as automation OEM business.
As tape technology continues its evolution, there are still a multitude of different tape technologies to
choose from, each with its own advantages and disadvantages in the key metric areas of capacity,
performance, reliability and price. Customers should continue to evaluate their options based on their
unique storage environment, their future growth requirements, their backward-compatibility needs, and
the advantages and disadvantages of the various tape technologies.