These lecture notes are copyrighted material. Some of the material is taken from slides provided by the text Operating Systems Concepts, by Silberschatz, Galvin, and Gagne.  The rest is due to CMSC 412 instructors.   Use of these pages for the class CMSC412 at the University of Maryland is permitted. Personal use of these notes by individuals at other locations is also permitted.  Any other use of this material requires permission of the author (Michael Hicks, and Jeff Hollingsworth).

<>Please don't hesitate to ask, we just like to know where the notes are being used.