This article needs additional citations for verification. Please help improve this articlebyadding citations to reliable sources. Unsourced material may be challenged and removed.
Find sources: "Digital Data Storage" – news · newspapers · books · scholar · JSTOR (February 2013) (Learn how and when to remove this message) |
![]() |
This article provides insufficient context for those unfamiliar with the subject. Please help improve the articlebyproviding more context for the reader. (August 2021) (Learn how and when to remove this message)
|
![]() | |
Media type | Magnetic cassette tape |
---|---|
Encoding | Lossless real-time |
Read mechanism | Rotating head |
Write mechanism | Rotating head, helical scan |
Developed by | Sony |
Usage | Data storage |
Extended from | Digital Audio Tape |
Released | 1989; 35 years ago (1989) |
Digital Data Storage (DDS) is a computer data storage technology that is based upon the Digital Audio Tape (DAT) format that was developed during the 1980s. DDS is primarily intended for use as off-line storage, especially for generating backup copies of working data.
A DDS cartridge uses tape with a width of 3.81mm, with the exception of the latest formats, DAT-160 and DAT-320, both which use 8mm wide tape. Initially, the tape was 60 meters (197 feet) or 90 meters (295 ft.) in length. Advancements in materials technology have allowed the length to be increased significantly in successive versions. A DDS tape drive uses helical scan recording, the same process used by a video cassette recorder (VCR).
Backward compatibility between newer drives and older cartridges is not assured; the compatibility matrices provided by manufacturers will need to be consulted.[1] Typically drives can read and write tapes in the prior generation format, with most (but not all) also able to read and write tapes from two generations prior. Notice in HP's article that newer tape standards do not simply consist of longer tapes; with DDS-2, for example, the track was narrower than with DDS-1.
At one time, DDS competed against the Linear Tape-Open (LTO), Advanced Intelligent Tape (AIT), VXA, and Travan formats. However, AIT, Travan and VXA are no longer mainstream, and the capacity of LTO has far exceeded that of the most recent DDS standard, DDS-320.
![]() |
This section is in list format but may read better as prose. You can help by converting this section, if appropriate. Editing help is available. (August 2021)
|
Format | Date | Tape width (mm) |
Track pitch (μm) |
Tape length (m) |
Native capacity (GB) |
Capacity assuming 2:1 compression (GB) |
Drum rotation speed (RPM) |
Data transfer speed (MB/s) |
---|---|---|---|---|---|---|---|---|
DDS-1 | 1989 | 3.81 | 13.6 | 60/90 | 1.3/2.0 | 2.6/4 | 2000, 2551 | 0.183 |
DDS-2 | 1993 | 3.81 | 9.1 | 120 | 4.0 | 8 | 4000, 4400, 5737, 8500 | 0.360-0.720 |
DDS-3 | 1996 | 3.81 | 9.1 | 125 | 12.0 | 24 | 3825, 4252 | <1.5 |
DDS-4 | 1999 | 3.81 | 6.8 | 150 | 20.0 | 40 | 11400 | 1.0-3.2 |
DAT-72 | 2003 | 3.81 | 5.4 | 170 | 36.0 | 72 | 8609.7, 10000 | 3.2 |
DAT-160 | 2007 | 8 | 6.8 | 154 | 80 | 160 | 6457 | 6.9 |
DAT-320 | 2009 | 8 | 153[3] | 160 | 320 | 12 | ||
(Gen 8) | canceled | 8 | ~300 | ~600 | ≥16 |
The next format, Gen 8, was canceled.[citation needed]
{{cite web}}
: CS1 maint: bot: original URL status unknown (link)
Magnetic-tape data storage formats
| |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Linear |
| ||||||||||||
Helical |
|
Standards of Ecma International
| ||
---|---|---|
Application interfaces |
| |
File systems (tape) |
| |
File systems (disk) |
| |
Graphics |
| |
Programming languages |
| |
Radio link interfaces |
| |
Other |
| |
List of Ecma standards (1961 – present) |