This article is from the storage FAQ part1, by Rodney D. Van Meter with numerous contributions by others.
A company called Creo, from Canada I believe, makes a large tape drive that uses ?1"? tape and gets a terabyte of data on a $10,000, 880 meter reel. The time to read the media (media granularity) is huge; at 3 MB/sec. it takes almost four days to read a tape! EMASS have aquired the rights to manufacture the optical tape drive from CREO. The drive ($350k) provides 1TB on line with data transfer at 3MBytes/sec and an average seek time of just 30 seconds. Optical tape media is supplied on 12.5" reels (capacity 1 TByte) by ICI Imagedata in the UK. Expected archival life 30yrs. Typical price of a reel is $8,500. (updated 1995/9/18, Duncan_Riddle@ici-imagedata.ccmail.compuserve.com) http://www.emass.com/Products/Hardware_Products/Drives/OTR/OTR_Top.html has some info.