Computer Science - Paper 1 Fundementals of Computer Systems

Hardware

The physical parts of a computer that you can touch

Software

Any program that can be run on a computer

Application Software

All the programs a user uses to perform a particular task

System Software

Covers a range of programs taht are concerned withe the more technical aspects of setting up and running the computer

What are the types of system software?

Utility Programs, Library Programs, Translators and Operating System Software

Utility Programs

Programs that perform specific common tasks related to running the computer

Library Programs

Code, data and resources that can be called by other programs

Example of utility software

Compression software, Anti-virus software, Back-up software, Registry cleaners

Translator

Software that converts programming language instructions into 1s and 0s

What are the 3 types of Translators?

Compilers, interpreters, assemblers

Operating System Software

A collection of software designed to act as an interface between the user and the computer and manages the overall operation of the computer. (It links together hardware, the applications and the user but hides the true complexity from the user and other software)

Virtual Machine

The concept that all complexities are hidden from the user and other software by the operating system

Resource Management

How an operating system manages hardware and software to optimise the performance of the computer

Scheduling

a technique to ensure that different users or different programs are able to work on the same computer, seemingly at the same time

Round-Robin Scheduling

Allocates each task a time slice of equal amount of processor time and passing access to the processor one task at a time

I/O Device Management

Controls the way in which the various inout and output devices are allocated, controlled and used by the programs that are using them

Device Driver

Every I/O device has a device driver which is the piece of software that enables the device to communicate with the OS

Memory Management

How the OS uses RAM to optimise the performance of the computer

Memory Management Routines

Check if there is enough memory available then allocate the apporopriate memory and load the file into those locations

Memory Map

Shows which blocks of memory have been allocated to each task

Paging

File Management

How an OS stores and receives files

What type of structure does file management use?

Hierarchical structure

Machine Code

The lowest level of code, made up of 1s and 0s

Disadvantages of Machine code

Not user-friendly, difficult to spot errors, easy to make mistakes, not portable as it is written fro a specific processor

Benefits of Machine code

No need for translation, will be executed quickly, processor will do exactly what you tell it to do