The TL891 can provide years of fully automated operation for backup, save and restore, and hierarchical storage management of critical data when coupled with a wide array of qualified industry-standard backup applications. The TL891 is offered as a standalone tabletop unit or as a scalable / stackable rack mount unit, with a removable 10 cartridge magazine, and integral bar code reader and either one or two Compaq DLT 35/70 drives.The MiniLibrary Expansion Unit assumes control over all attached TL891 modules, allowing for the creation of a multi-module virtual library in a single rack mount configuration. It also provides an additional 1.1 TB of capacity (no drives). The Expansion Unit supports up to (5) five additional modules in a single rack mount configuration. With the use of a special pass-through mechanism, all tapes within this multi-module configuration are available to all DLT drives, making a single virtual library. This true scalability of performance and capacity allows the end user the opportunity to configure the device to meet their specific requirements, as well as offers a "pay as you grow" solution for easy capital management. The multi-unit configuration can also be disassembled at any time and each module redeployed independently to meet changing corporate backup strategies.