This article is from the storage FAQ part2, by Rodney D. Van Meter with numerous contributions by others.
MountainGate has announced that they will have, later this year, a 300-cartridge autochanger. IBM of course makes numerous autochangers for NTP; the 3494 and 3495 models both support it. More info at http://www.storage.ibm.com/storage/hardsoft/tapls.htm. (They probably have smaller libraries, too.) Word in the newsgroup has it that STK robots won't support Magstar due to the rivalry between IBM and STK. (rdv,1996/3/12)