IBM 3490 Tape Subsystem
In the early 1990s, IBM extended the capabilities of its 3480 product family by launching the 36-
track 3490E drive and a new extended-length chromium dioxide tape. The 3490E provided 800MB
of storage in the same cartridge format as the earlier 3480. With Improved Data Recording
Capability (IDRC), introduced in 1986, the capacity of the 3490E was expanded to over 2.4GB, the
highest data capacity at that time.
The IBM 3490 Enhanced Capability (3490E) Model A10 and A20 Control Units and B20 and B40
Drive Units were the newest members of the 3490 family of Magnetic Tape Subsystems when they
were announced in February 1991. The B20 and B40 Tape Drive Units wrote in a new Enhanced
Capability format. The new Enhanced Capacity Cartridge System Tape doubled the storage capacity
of the cartridge and could reduce the number of cartridges needed for normal back-up and archival
operations. Another benefit of the 3490E was that it could use IBM's new ESCON (Enterprise
Systems Connection architecture) channel interface -- first delivered in 1987 -- to locate the tape
subsystem up to 23 km (14.2 miles) from the processor (ES/3090, ES/9000, ES/9370, 308x or
43 8 1).
Also announced in February 1991 were the Models D41 and D42, which offered significant
performance and cartridge capacity improvements to midrange and intermediate system users. They
were designed to be used primarily for save/restore and data interchange, and could be attached to -
IBM ES/3090, ES/9000, ES/9370, 308x or 4381 processors.
One year after the initial 3490E roll-out, IBM introduced the Models C10 (control unit with a single
tape drive), C11 (control unit with a single tape drive and ACL) and C22 (control unit with two tape
drives and ACLs) low-cost, rack-mountable members of the family. The 400MB or 800MB non-
compacted cartridge capacity, along with the IDRC standard feature and Automatic Cartridge
Loaders (ACL), significantly reduced operator media handling. These 3490E C models provided
midrange users -- such as the IBM AS/400 E35 and E45 -- with a very competitive tape solution,
and were excellent replacement products for older 10.5-inch reel drives. The C models supported
the AS/400 9406 models and the ES/9000 Model 9221 processors.
In February 1994 IBM debuted the 3490 Magnetic Tape Subsystem Enhanced Capability Models
E01 and E11 as the most reliable tape systems available from IBM for the RISC System/6000 and
AS/400 processors. Compared to other 3490E units, the new models offered: additional capacity,
higher performance in many situations, lower price and only 26 percent of the size of a Model C11.
The Model E01 was a table-top version and the Model Ell was a rack-mount version. Each
included a seven-cartridge Cartridge Stack Loader (CSL), a 16-bit, fast-and-wide, SCSI-2
differential interface, a 3490E tape transport and an integrated control unit. The maximum effective
throughput was up to 6.5MB a second.
The E01 and E11 with their seven-cartridge CSL provided an automated, unattended backup
capacity of up to 16.8GB with compressible data (uncompressed the capacity was up to 5.6GB).
The standard CSLs automatically loaded and unloaded cartridges as they were filled, improving
efficiency by reducing the need for operator handling.
The 3490E Models E01 and E11 could be used:
•	To create tapes for archive ﬁles.
•	To backup and restore systems in case of system or disk storage problems.
•	For off-site data storage for disaster recovery.
•	For data interchange with other systems.
Three years after the debut of the E models, IBM announced the 3490E F00, F01 and F11 models to
provide reading and writing capability to 3490 magnetic tape cartridges for small and midrange
system users. They could read and Write 36-track and 18-track cartridges with a single drive,
including Improved Data Recording Capability (IDRC), when attached to RS/ 6000, AS/400 and
open systems environments.
The new models included a single drive version (F00), a desk-side unit (F01) and a rack-mounted
model (F11). The desk-side and rack-mounted models featured an integrated 10-cartridge
autoloader. All three achieved sustained data transfer rates of 3MB a second, and -- with IDRC
enabled -- sustained data rates of up to 6.8MB could be attained.
The integrated autoloader on Models F01 and F11 allowed up to 8GB (24GB compressed) of
magnetic tape storage in two cubic feet of space.
In October of 1997, IBM announced the 3490E Model F1A tape drive to provide high-performance,
high-reliability 3490 tape cartridge access in the IBM 3494 Tape Library Dataserver. Standard A
features of the FlA are 18-track read and 36-track read/write, 3480 and 3490 tape interchange, and
IDRC -- which provides up to 2.4GB of capacity per tape cartridge.
The FlA provides effective data rates up to 6.8MB per second, sustained data rates of 3MB per
second and burst data rates of 20MB per second.