Categorias: Todos - output - input - memory - peripherals

por stephen chen 13 anos atrás

609

CompSys

A computer system can be divided into several key components, each with specific functions and characteristics. Peripherals are devices that connect to the system unit, facilitating input and output operations.

CompSys

Computer System電腦系統

Version 1.0

Hardware硬件

Peripherals週邊設備

devices other than the system unit

processing

sound card

display / graphic card

storage devices

units

GB

MB

KB

byte - 8 bits

bit

the smallest / basic computer storage unit. It stores eithe a 0 or a 1.

secondary storage

storage devices which are not the main memory all fall into this category.

semi-conductor

USB thumb drive

flash memory card

xD

Memory Stick

SD

CF

optical

DVD

CD

magnetic

magnetic tape

Mainly for server backup.

harddisk

The major secondary storage device.

floppy

output devices

printer

ppm (page per minute) - speed

dpi (dot per inch) - quality

speaker

monitor

pixel

color depth

Number of colors can be displayed. Usually measured in bit. For example, 4-bit color means 2^4 = 16 colors.

resolution

The number of pixels can be displayed. There are many standards, for example , VGA, SVGA, XGA etc.

input devices

barcode reader

scanner

biometrics

the use of personal characteristics / features to identify a computer user. In that way, people don't need to remember their computer passwords as they use their body traits as passwords.

iris recognition

finger print

pointing

track ball

touch pad

mouse

System Unit
Main memory

CMOS

1. non-volatile

2. store system information (e.g. date, harddisk info, RAM info etc)

3. data inside it can be updated/ changed.

ROM

stores:

1. S (Basic Input Output System) - a program to be loaded into RAM for checking the computer hardware configuration

2. Boot program - a program to start the computer

Characteristics:

1. store permanent instruction

2. read ony / can't be written

3. small in capacity

4. non-volatile

RAM

1. volatile - loss data when power off

2. store temporary data and instructions to be used by CPU

3. upgrade - memory capacity can be changed

Motherboard

ports 連接埠

DVI

VGA

LAN

PS2

USB

bus 總線

slots

CPU

performance factor

word length字長

It means the number of data that can be processed at one time. Usually measured in bits, for example, 16-bit, 32-bit and 64-bit.

clock speed時鐘頻率

e.g. 2.8GHz

2.8GHz means in a second there are 2.8 billion instruction cycles.

the faster the better

Hz

1 instruction cycle

cache快取記憶體

fast memory unit located inside CPU to store frequently used instructions and data for the CPU. Compare to RAM, it is

1. faster

2. small in capacity 容量較RAM少 (usually measure in MB)

3. more expensive

Arithmetic Logical Unit

Control Unit

Software軟件

Application Software應用軟件

Application software refers to programs that help users get their works done by using the computer. The list is only a small sample.

Communication
Sound editing
Graphics
Presentation
Spreadsheet
Database (DBMS)
Word Processing
System Software系統軟件

System sofware refers to programs which make your computer works.

Driver 驅動程式

programs which helps an OS to communicate and manage a peripheral device.

Utility Program實用軟件

programs to maintain your computer's health and improve the computers performance.

examples

Screen Saver

System optimizer

Encryption

Data Recovery

Data Compression

Disk Defragmentation

Anti-virus

Operating System操作系統

Functions:

1. allocate system resource

2. manage files

3. monitor activites

User Interface用戶介面

Graphical User Interface (GUI)

1. easier to learn and master

2. consume a lot more system resource

3. works slower

Command Line Interface (CLI)

1. need less system resource

2. difficult to learn and master

3. works faster

types

multi user

several users can be using the same computer or even the same program on that computer at the same time.

single user

only one user can use the computer at a particular time.

multi tasking

be able to handle multiple tasks at the same time.

single tasking

be able to handle ONE task at a particular time.

example

Linux

Apple OSX

Windows

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