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.
| 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 | 128 | 36 | |
| Recording density [bytes/inch] | 864,000 | 76,000 | |
| IBG（mm） | 2 | 2 | |
| Tape speed [m/s] | 2 | 2 | |
| Tape speed [m/s] | 9.0 /17.0 *1 | 3.0/6.0 /9.0 | |
| Number of drives | 4 | 2 | 4 |
*1. When connected to an ACONARC channel.
