1984: Tape cartridge improves ease of use
Magnetoresistive head & new media increase speed and density
IBM announced a major departure from traditional reel-to-reel tape for bulk data storage in 1984. At about 25% of the size of a standard 10.5-inch reel of tape, the IBM 3480 magnetic tape subsystem employed a new, easier to handle, 200 MB capacity 4 x 5 x 1 inch rectangular cartridge that addressed the demand for smaller size while delivering faster data rates, improved reliability, and reduced maintenance costs. The format attracted other producers, including Fujitsu, M4 Data, Overland Data, StorageTek and Victor Data Systems (VDS) who manufactured 3480-compatible products until the early 2000s. DEC, Philips and other vendors offered rebranded systems. The rectangular cartridge form factor continues to be used today in modern tape drives.
Designed at an IBM Tucson, AZ facility devoted to advanced tape drives and storage control units, the 3840 incorporated important new features. These included the first successful commercial use of magnetoresistive (MR) thin-film read heads in a magnetic recording application,multi-bit error correction code enabled by embedded software (microcode), elimination of tall vacuum columns by using buffers, and a new chromium dioxide tape. DuPont had introduced chromium dioxide (CrO2) particle tape in the late 1960s for its higher coercivity and magnetic stability compared to ferric oxide and licensed it to BASF, Memorex and Sony for audio and video recording. IBM improved the media with binders and lubricants for data system applications.
The 3480 18-track head family was extended to 36-tracks in the 3490E drive in 1991. Together with a longer chromium dioxide tape, the 3490E provided 800 MB of storage in the same cartridge format as the 3480. Improved Data Recording Capability (IDRC) data compression later expanded the capacity of the 3490E to over 2.4 GB.
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- “Rodriguez, Juan oral history” Computer History Museum Oral History # 102702129 (2009-07-13)
- “IBM Tape History - Session 1: Tape media” Computer History Museum Oral History # 102737992 (2015-10-12)
- “IBM Tape History - Session 2: Overview of tape products and product management” Computer History Museum Oral History # 102737994 (2015-10-13)
- “IBM Tape History - Session 3: 3480 tape drive” Computer History Museum Oral History # 102738021 (2015-10-14)
- “IBM Tape History - Session 4: LTO Virtual Company panel” Computer History Museum Oral History # 102738023 (2015-10-15)
- “IBM Tape History - Session 5: Recovery of tapes damaged in Challenger disaster” Computer History Museum Oral History # 102738025 (2015-10-15)