【Hitachi】 H-6495 Cartridge-Based Magnetic Tape Unit

Hitachi began shipping the H-6495, a magnetic tape unit using a new 128-track format, in June 1997. The 128-track format, along with three-times data compression, enabled high-density recordings — about 30 GB of data per tape cartridge (10 GB of uncompressed data). Data transfer speeds over ACONARC channel connections were raised from the previous 9 MB per second to 17 MB per second.

Hitachi provided two H-6495 magnetic tape units to connect to magnetic tape libraries: the H-6495-524L with four drives and the H-6495-522LB with two standalone drives. With the H-6495-524L, up to eight units (32 drives) could be connected to one library unit. It could be connected to the enhanced H-6952 libraries, the H-6952-5 and the H-6952-6. Depending on the configuration, the tape storage capacity per library ranged between 9.9 and 263 terabytes.

Specifications of the H-6495 magnetic tape unit
Model name H-6495-524L H-6495-522LB H-6488-1(for reference)
Magnetic tape specifications width: 1/2 inch, length: 315 m width: 1/2 inch, length: 315 m
width: 1/2 inch, length: 165 m
Number of tracks 12836
Recording density [bytes/inch] 864,00076,000
IBG(mm) 22
Tape speed [m/s] 22
Tape speed [m/s] 9.0 /17.0 *13.0/6.0 /9.0
Number of drives 424

*1. When connected to an ACONARC channel.