Basic concepts of a computer system V1.0 (21/11/2005)

Basic concepts of a computer system Computer Systems is composed of hardware, software and data Hardware includes peripherals like keyboard, monitor, Central Processing Unit (CPU)

Software refers to programs that control hardware

Data refers to facts represented by words and number, like: –HKID –Age –Name –Examination Grades

Program is used to process Data to produce output Dataprocess  output 

Basic components of Computer Systems includes Central Processing Unit (CPU) 、 Main Memory 、 Peripherals Peripherals include input device, output device and back up storage A computer Mother Board

output device: Monitor input device: Keyboard backup storage: Floppy drive Processing Unit output device: Printer input device: Mouse

Central Processing Unit (CPU) is used to analyze and execute instructions Includes control units, arithmetic and logic processing units and some registers Central Processing Unit (CPU)

Main Memory include Random Access Memory (RAM) 、 Read Only Memory (ROM) RAM is used for short-term storage. Data will be cleared up on machine shut down ROM is used for long term storage ， data persists across machine shutdown cycles. But it is NOT rewritable.

input device includes keyboard, mouse, etc. To accept user input and transfer to CPU

output device includes printer, monitor, etc. A media to display result to users

backup storage is used for storing data to- be-used in future

Computer components are connected by cables input device Main Memory (RAM, ROM) CPU output device secondary storage System Unit

Exercises ： –1. List five components of Computer Systems hardware and give corresponding examples –2. List 3 examples of software and briefly describe its use