Operating System-IV

1. Describe the Buddy system of memory allocation.

Free memory is maintained in linked lists, each of equal sized blocks. Any such block is of size 2^k. When some memory is required by a process, the block size of next higher order is chosen, and broken into two. Note that the two such pieces differ in address only in their kth bit. Such pieces are called buddies. When any used block is freed, the OS checks to see if its buddy is also free. If so, it is rejoined, and put into the original free-block linked-list.

Operating System-III

1. What is an Operating System (OS)?

An operating system is basically software that makes everything in the computer work together smoothly and efficiently. Basically, it controls the "overall" activity of a computer.

Operating systems have three basic jobs they must do:

•Control Hardware - The operating system controls all the parts of the computer and attempts to get everything working together.

•Run Applications - Another job the OS does is run application software. This would include Microsoft Office, WinZip, games, etc.

•Manage Data and Files - The OS makes it easy for you to organize your computer. Through the OS you are able to do a number of things to data including copy, move, delete, and rename it. This makes it much easier to find and organize what you have.