1. 
   QDOS
   Quick and Dirty Operating System
   Found op http://www.encyclo.co.uk/visitor-contributions.php
   
   
2. 
   QDOS
   (operating system) The Sinclair QL's proprietary operating system. The origin of the name is uncertain (a weak pun on kudos, perhaps, as Unix was on Multics). There was another OS around from the birth of personal computers called Q.D.O.S. - Quick And Dirty Operating System. QDOS might also stand...
   Found op http://foldoc.org/QDOS
   
   
3. 
   qdos
   1) Quick and dirty operating system
   Found op http://www.mijnwoordenboek.nl/EN/crossword-dictionary/qdos/1
   
   

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