The disadvantage of tape drives is that they are sequential-access devices, which means that to read any particular block of data, you need to read all the preceding blocks. This makes them much too slow for general-purpose storage operations. However, they are the least expensive media for making backups.

Exabyte's home page 
Home page for Exabyte Corporation, a manufacturer of tape drive products. This page offers links to products and technology, support and service, and company information.

Comparing helical-scan and digital linear tape (DLT) technology
From Quantum, this technical information paper compares DLT tape drives to helical-scan tape technology.

Transitional Technology, Inc.
Home page of Transitional Technology Inc., designer and manufacturer of 8mm, AIT, DLT, and DTF tape subsystems and libraries.

Yahoo!'s tape drives page
Yahoo!'s directory of tape drives.