【Fujitsu】 F6484 Magnetic Tape Unit

The F6484, which began shipping in June 1999, was Fujitsu’s high-speed magnetic tape unit that used IBM 3590-format tape media. Fujitsu already had the F6470 magnetic tape unit (which started shipping in September 1987) that worked with IBM 3480-format tape media, the F6473A (which started shipping in March 1991), which could be expanded to house up to four drives, and the F6473K (which started shipping in July 1993), which recorded in a 36-track format. The F6484, however, dramatically increased the storage capacity per tape over 36-track magnetic tape units by recording in a 128-track format and, thus, met mounting needs for more data storage.

The F6484 had the following features:
  • (1)The 128-track magnetic head, which used thin-film technology, could record 86,360 bytes per inch, allowing up to 10 GB of data to be written to one tape
  • (2)The F6484 recorded 128 tracks by making eight 16-track passes in a serpentine pattern
    Note: The name serpentine came from the snake-like pattern that resulted from multi-pass tape recording
  • (3)The F6484 could transfer data at 13.5 megabytes per second
Specifications of the F6484 magnetic tape unit
magnetic tape unit
(for reference)
magnetic tape unit
(for reference)
magnetic tape unit
Initial shipping date June 1999 July 1993 March 1991
Tape media Single-reel tape cartridges
(width: 1/2nch, length: 2,070 feet)
Single-reel tape cartridges
(width: 1/2nch, length: 1,080 feet*1)
Single-reel tape cartridges
(width: 1/2 inch, length: 540 feet)
Cartridge dimensions [mm] 110 x 128 x 26 (w x d x h) 110 x 128 x 26 (w x d x h) 110 x 128 x 26 (w x d x h)
Number of drive decks [decks/unit] FACOM6484B4:4
Recording density [bytes/inch] 86,360 75,742 37,871
Recording tracks 128 (eight-pass 16-track serpentine) 36 (two-pass 18-track serpentine) 18
Recording format RLL GCR GCR
Data transfer speed [MB/s] 13.5 3.0 3.0
Tape speed [inches/s] 156 78.7 78.7
Storage capacity [per cartridge] 10 GB max.*2
(~20 GB with data compression)
800 MB max.*2
(~2,400 MB with data compression)
200 MB max.*3
(~400 MB with data compression)
Access time [ms] 20 25 25
Rewind time [s] 55 40/80(*1) 40
Unload time [s] 20 7/10*1 7
Autoloader Autoloader with 12-cartridge capacity Autoloader with six-cartridge capacity Autoloader with six-cartridge capacity

*1. With double-length tape.
*2. When recording data in 32 Kbyte blocks with double-length tape.
*3. When recording data in 32 Kbyte blocks.

F6484 Magnetic Tape Unit