Innovations in tape storage automation at IBM

In the mid-1980s, tape storage appeared to be heading toward the graveyard. Storing information on large reels of tape that had to be manually mounted was expensive, inefficient, and prone to human error. In addition, competition from hard disk drives (HDDs) was growing. Data access on HDD was faster because the data was stored in a manner for rapid random access, not linearly as on tape, and HDD capacity was rapidly growing. Then, in 1984, IBM introduced the half-inch tape cartridge (3480), which was novel in its small form factor. In 1986, an automatic loading mechanism followed. In 1987 and 1988, competitors introduced the first automated tape libraries to use the half-inch tape cartridge. Suddenly, tape storage became considerably easier to use and more efficient. With automation, it also represented the least expensive way to store data. In 1993, IBM introduced the 3495 tape library, and now offers several different automated libraries ranging from the smaller 3575 MP and 3581/3583 models to very large libraries such as the 3494 and 3584 models. This paper examines the history of IBM tape storage and automation products, including the engineering challenges that were met in response to users' pressing requirements; it also examines the future of automated tape storage.