【Fujitsu】 FACOM 6475 Cartridge Tape Unit

Completed in June 1985, the FACOM 6475 was a cartridge tape unit for the Fujitsu FACOM M Series. FACOM 6475 used VHS media. At the time, backing up data from magnetic disk units to magnetic tapes involved problems like the need to secure a storage location, increasing complexity of management, and an increase in the backup work load due to the increase in processing time and the number of tapes. This unit was developed to resolve these problems, and it had the following features:

(1) High-speed backup processing
Twice the performance of the FACOM 613A magnetic tape unit—Fujitsu's fastest at the time.
(2) Improved tape storage space efficiency
A maximum memory capacity of 280 Mbyte per tape was achieved using VHS media and high-density recording (32,000BPI), thereby reducing storage space to approximately 1/8 compared to full-size open reel tape.
(3) Easier operation
The burden on the operator was greatly reduced by using easy-to-handle cartridge tapes, and a cartridge magazine capable of holding a maximum of 10 tapes (Note 1), thereby enabling backup processing for a maximum of 2.8Gbyte (Note 2) in a single operation.

(Note 1) In case of the FACOM 6475A2

(Note 2) The size of one FACOM 6425 magnetic disk unit (4 volumes) at that time

FACOM 6475 Cartridge Tape Unit Specifications
  FACOM 6475A1/A2
Cartridge tape unit
(Reference) FACOM 613A
Magnetic Tape Unit
Completion date June 1985 December 1977
Tape media VHS Cartridge tape
(Width 1/2inch,Length 800feet)
Open reel tape
(Width 1/2inch,Length 2400feet)
Number of drive decks (deck/unit) 2 1
Recording density(byte/inch) 32,000 6,250/1,600
Number of recording tracks 18 9
Recording system bi-GCR GCR/PE
Data transfer speed (MB/s) 2.5 1.25/0.32
IBG length (inch) 0.08 0.3/0.6
Tape running speed(inch/s) 78.1 200
Memory capacity (*1) (MB/volume) Max. 280 Max. 170/44
Access time (ms) 22 1.0
Repositioning time (ms) 85 -
Rewind time (s) Max. 52 Max. 45
Cartridge magazine mechanism Yes (FACOM 6475A2)

*1: When recorded with 32Kbyte block size

FACOM 6475 Cartridge Tape UnitFACOM 6475 VHS CartridgeFACOM 6475 magazine