ctos

from The Free On-line Dictionary of Computing (8 July 2008)

CTOS

   1. <operating system> {Computerised Tomography Operating
   System}.

   2. <operating system> {Convergent Technologies Operating
   System}.

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

CTOS
       Cassette Tape Operating System (OS, Datapoint)

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