IBM 3480 Family
Encyclopedia
The 3480 tape format is a magnetic tape data storage
format developed by IBM
. The tape is one half inch wide and is packaged in a 4"x5"x1" cartridge. The cartridge contains a single reel; the takeup reel is inside the tape drive.
Because of their speed, reliability, durability and low media cost, these tapes and tape drives are still in high demand. A hallmark of the genre is transferability. Tapes recorded with one tape drive are generally readable on another drive, even if the tape drives were built by different manufacturers.
Tape drives conforming with the IBM 3480 product family specification were manufactured by a variety of vendors from 1984 to 2004. Core manufacturers included IBM, Fujitsu
, M4 Data, Overland Data, StorageTek and Victor Data Systems (VDS). Various models of these tape drives were also marketed under other brands, including DEC
, MP Tapes, Philips
, Plasmon, Qualstar
, Tandem
, and Xcerta.
IBM designated all versions of 3480 and 3490E tape drives as members of the 3480 Product Family.
and high voltage SCSI
interfaces. The advent of the SCSI interface made it possible to connect 3480 family tape drives to personal computers, which enabled mainframe-to-pc data exchange.
It was also distinguished by a relatively high data transfer rate: 3 megabyte
s per second. This was because it was able to read and write linear data across 18 recording tracks simultaneously, or 38,000 bytes per inch of tape. IBM's prior technology employed 9 recording tracks with a data density of 6,250 bytes per inch of tape, so the 3480 format was greeted as a major breakthrough. The IBM 3480 cartridge stored 200 megabytes in a modest 4x5 inch cartridge compared to the previous technology's 140 megabytes on a 10.5 inch diameter (2400 foot length) reel of 1/2" tape. The 3480 its successors are streaming drives. The 3480 was initially a disaster, because it would consistently underrun as the 3 MB/s bus and tag channels and the 3 MB/s drives could not feed the 3MB/s second tape drives because of various interferences such as seeks. The streaming drives would then have to stop, back up and restart, reducing throughput to under 200 KB/s.
While IBM offered 3480 tape drives with bus and tag interfaces, other manufacturers sold models with SCSI interfaces.
A 3480 tape drive with IDRC uses the same data cartridges as a standard 3480 tape drive. It can read and write standard 3480 tapes.
3490E tape drives were available from a variety of manufacturers with bus and tag, ESCON, or high voltage SCSI interfaces, and were capable of data transfer speeds up to 20MB per second.
While 3490E data cartridges are the same dimensions as 3480 cartridges, the tape media is the same only longer. 3490E tape is optimized for 36-track recording heads, instead of 18-track recording heads. Nevertheless, some 3480 tape drives can record on 3490E media.
Some 3490E tape drives are able to read tapes recorded by 3480 tape drives. Others can also write tapes that can be read by 3480 tape drives. But many 3490E tape drives can only read/write 36-track tapes.
Evolution of the IBM
3480 Product Family
ECMA Standards
Magnetic tape data storage
Magnetic tape data storage uses digital recording on to magnetic tape to store digital information. Modern magnetic tape is most commonly packaged in cartridges and cassettes. The device that performs actual writing or reading of data is a tape drive...
format developed by IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
. The tape is one half inch wide and is packaged in a 4"x5"x1" cartridge. The cartridge contains a single reel; the takeup reel is inside the tape drive.
Because of their speed, reliability, durability and low media cost, these tapes and tape drives are still in high demand. A hallmark of the genre is transferability. Tapes recorded with one tape drive are generally readable on another drive, even if the tape drives were built by different manufacturers.
Tape drives conforming with the IBM 3480 product family specification were manufactured by a variety of vendors from 1984 to 2004. Core manufacturers included IBM, Fujitsu
Fujitsu
is a Japanese multinational information technology equipment and services company headquartered in Tokyo, Japan. It is the world's third-largest IT services provider measured by revenues....
, M4 Data, Overland Data, StorageTek and Victor Data Systems (VDS). Various models of these tape drives were also marketed under other brands, including DEC
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
, MP Tapes, Philips
Philips
Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....
, Plasmon, Qualstar
Qualstar
Qualstar Corporation is an American manufacturer of magnetic tape data storage products, based in Simi Valley, California. It was founded in 1984 as a 9 track tape drive manufacturer, and now makes tape library products...
, Tandem
Tandem
Tandem is an arrangement where a team of machines, animals or people are lined up one behind another, all facing in the same direction....
, and Xcerta.
IBM designated all versions of 3480 and 3490E tape drives as members of the 3480 Product Family.
Interfaces
Tape drives built for the 3480 were initially designed for mainframe computers. Therefore, the first 3480 tape drives communicated through a bus and tag interface. Later models were able to take advantage of ESCONESCON
ESCON is a data connection created by IBM, and is commonly used to connect their mainframe computers to peripheral devices such as disk storage and tape drives. ESCON is an optical fiber, half-duplex, serial interface. It originally operated at a rate of 10 Mbyte/s, which was later increased to...
and high voltage SCSI
SCSI
Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...
interfaces. The advent of the SCSI interface made it possible to connect 3480 family tape drives to personal computers, which enabled mainframe-to-pc data exchange.
3480
The first 3480 tape drives were introduced in 1984. The IBM 3480 was the first tape drive to employ thin-film heads and the first to use chromium dioxide tape.It was also distinguished by a relatively high data transfer rate: 3 megabyte
Megabyte
The megabyte is a multiple of the unit byte for digital information storage or transmission with two different values depending on context: bytes generally for computer memory; and one million bytes generally for computer storage. The IEEE Standards Board has decided that "Mega will mean 1 000...
s per second. This was because it was able to read and write linear data across 18 recording tracks simultaneously, or 38,000 bytes per inch of tape. IBM's prior technology employed 9 recording tracks with a data density of 6,250 bytes per inch of tape, so the 3480 format was greeted as a major breakthrough. The IBM 3480 cartridge stored 200 megabytes in a modest 4x5 inch cartridge compared to the previous technology's 140 megabytes on a 10.5 inch diameter (2400 foot length) reel of 1/2" tape. The 3480 its successors are streaming drives. The 3480 was initially a disaster, because it would consistently underrun as the 3 MB/s bus and tag channels and the 3 MB/s drives could not feed the 3MB/s second tape drives because of various interferences such as seeks. The streaming drives would then have to stop, back up and restart, reducing throughput to under 200 KB/s.
While IBM offered 3480 tape drives with bus and tag interfaces, other manufacturers sold models with SCSI interfaces.
3480 IDRC
In 1986, IBM added a hardware-based data compression option: Improved Data Recording Capability (IDRC). A 3480 tape drive with IDRC could record up to 400 megabytes on a single tape. The 3480 IDRC format is also commonly known as the 3490 recording format.A 3480 tape drive with IDRC uses the same data cartridges as a standard 3480 tape drive. It can read and write standard 3480 tapes.
3490E
IBM introduced the 3490E tape drive in 1991. Its 36-track head was able to record 800 megabytes of data on a single tape. The IDRC option allowed it to record up to 2400 megabytes on a single extended tape. The last 36-track tape drive manufacturer, VDS, discontinued production late in 2004, after IBM announced that it would no longer supply 36-track thin film tape heads.3490E tape drives were available from a variety of manufacturers with bus and tag, ESCON, or high voltage SCSI interfaces, and were capable of data transfer speeds up to 20MB per second.
While 3490E data cartridges are the same dimensions as 3480 cartridges, the tape media is the same only longer. 3490E tape is optimized for 36-track recording heads, instead of 18-track recording heads. Nevertheless, some 3480 tape drives can record on 3490E media.
Some 3490E tape drives are able to read tapes recorded by 3480 tape drives. Others can also write tapes that can be read by 3480 tape drives. But many 3490E tape drives can only read/write 36-track tapes.
Evolution of the IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
3480 Product Family
| Format | Intro Date | Capacity (MB) | Tracks |
|---|---|---|---|
| 3480 | 1984 | 200 | 18 |
| 3480 IDRC | 1986 | 400 | 18 |
| 3490E | 1991 | 800 | 36 |
| 3490E IDRC | 1992 | 2400 | 36 |
Beyond 3480
The 3480 magnetic tape format family has been superseded by the IBM 3590 Family of magnetic tape formats, which is distinguished by much higher transfer rates and densities. Tape head sizes at this writing: 128-track, 256-track and 384-track. IBM's name for these drives is Magstar.External links
ECMA Standards