Tandon builds tape drives. Tandem builds "fault tolerant" systems. When I was still at PacBell, we considered acquiring Tandem. It would have been a valuable addition to keep the IT shops up with fault tolerant systems. Tandem was excited about the new "non-stop UNIX". A demo was arranged at the San Ramon office. I couldn't attend due to deadlines, but my cohort in crime David St Pierre did attend. Tandem set up the machine and shortly thereafter the "non stop UNIX" stopped. It was down all day. It never ran while anyone of importance was present to see it. Suffice to say that we didn't proceed with the acquisition plans.
Thanks for the correction. You're right. Actually, a company that I was doing contract work for had a pair of the Tandems installed at their "hot site" for the very reason you mentioned... "Non-stop" computing. A terrific idea. However, not even the Compaq guys (former Tandem guys) could get the things to run reliably. One thing I remember was that the cache battery backups used D-cell alkaline batteries...
It was a really expensive disaster for a very large financial institution.
Mark