1. CSE111: Great Ideas in Computer Science Dr. Carl Alphonce 219 Bell Hall Office hours: M-F 11:00-11:50 645-4739 alphonce@buffalo.edu

2. cell phones off (please) 2

3. Announcements Exam 1 handback Exam 1 solution is posted Reminder: HW2 due on Friday 3

4. Today’s Agenda Operating Systems –Responsibilities –Components –Processes –Examples from Windows/Unix 4

5. Hierarchy of software User-level applications System utilities User-interface to operating system kernel (window manager, shell) Kernel 5

6. http://upload.wikimedia.org/wikipedia/commons/e/e1/Operating_system_placement.svg 6

7. http://commons.wikimedia.org/wiki/File:Kernel-exo.png 7

8. http://commons.wikimedia.org/wiki/File:Kernel_Layout.svg 8

9. Responsibilities Shell/Window manager –Interactions with users File manager –Manages files in secondary storage (e.g. stored on a hard drive) –Directories/Files/Permissions Device manager / device drivers –Printers, cable modems, USB sticks, displays, etc. Memory manager –Manages main memory –Virtual memory and paging Process manager –Controls access to CPU 9