What is an operating system (OS)?
Which OS have you used? Which do you know exist?
Why do you study operating systems?
What does an OS do? Which parts (components) does it consist of?
OS sits "between the hardware and the software".
From few, extremely expensive and slow, computers, to modern interactive computing.
Abstractions of hardware makes the computer easier to use and program.
Program which can run on CPU, using other resources
Operations: create, start, stop, schedule (when should it run?), interact (with processes/users)
All programs (instructions) and data must be in main (physical) memory for CPU to use (fetch/store).
Files, directories, file systems: stored on secondary/persistent storage medium.
I/O using keyboard, screen, disk, network...
What time is it now? How long time has passed now? Awake me in 3 ms! (Needed also internally, e.g. for scheduling)
Examples of classifications/aspects:
Follows book pretty closely (chapters 1-15).
Lab: process management in Unix/Linux.
Lab: process synchronisation and shared memory
Lab: Unix file system
An opportunity to learn more, in depth: write a short PM on a subject in operating systems and present it to the others.