Operating Systems

1. Briefly, what is an operating system?

An operating system serves as a hardware/software interface, acts as a repository for common, shared routines and defines a platform for constructing and executing application software.

2. An operating system presents an application programmer with a relatively "friendly" hardware/software interface. What does this mean? Why is it important?

The user interface, sometimes called the shell, provides a mechanism for the user and application programs to communicate with the operating system and request operating system support. It is important because it incorporates a user interface for file management routines, device management routines, memory management routines, and processor management routines.

5. List and briefly describe the five primary components of a modern operating system?

User Interface which provides a mechanism for the user and application programs to communicate with the operating system and request operating system support. File management which incorporates a routine that allows the user or programmer to create, delete, modify, and manipulate files by mane. The device management function is responsible for controlling communications with the system's peripheral devices such and the keyboard, the display screen, the printer, and secondary storage.

Memory management is concerned with managing the system's main memory resources as the computer runs, allocating space to applications as needed and ensuring that those applications do not interfere with each other. Processor management is concerned with efficiently managing the processor's time.

6. The components of an operating system are not independent; they work closely together. Briefly explain.

Say you have just issued a request to the shell to open a file. The file system accepts the file name and determines the file's actual location on disk. The device management routines then use that physical location to physically access the disk and read the file. Meanwhile, memory management ensures that space is available to hold the file once it enters memory, and processor management guides the processor through the task of supporting the I/O operating.