This article is from the storage FAQ part1, by Rodney D. Van Meter with numerous contributions by others.
Square cartridge: serpentine IBM 3480 - 18 track - 200 MB/cartridge, 1984 IBM 3490 - Smaller packaging, IDRC standard, 1989 reports that it is a 3480 in ID string IBM 3490E - 36 track, double length - 800 MB/cartridge native, 1992 IDRC data compression is also available. These drives have traditionally come from the mainframe vendors -- IBM, Fujitsu, Storage Tek, etc. They were originally very large objects, with vacuum columns and mainframe interfaces, the size of large filing cabinets. However, recently they have become available in smaller packages, 19" rack mount or table top, and with interfaces such as SCSI. Here's one from last year that I recently dug out of some old mail: IBM has just made generally available the following: 3490E Model E SCSI tape drive fast/wide differential IDRC compression 3 MB/sec at the tape head, 6.5 MB/sec with compression approx 800 MB tape capacity with out compression, 2.4 GB with a 3:1 comp 7 tape CSL(cartridge stack loader) Desk top and rack mount List $27,000 email@example.com, 94/4/11 There's also a standalone drive with a small autoloader from a company called Overland Data. Their L490e is a win because it reads and writes both 18 and 36 track tapes. At $20K it's reasonably priced. For the www-enabled, see http://www.ovrland.com/~odisales. (firstname.lastname@example.org, 94/12/21)