Version 1.0
System Software系統軟件
System sofware refers to programs which make your computer works.
Operating System操作系統
Functions:1. allocate system resource2. manage files3. monitor activites
example
Windows
Apple OSX
Linux
types
single tasking
be able to handle ONE task at a particular time.
multi tasking
be able to handle multiple tasks at the same time.
single user
only one user can use the computer at a particular time.
multi user
several users can be using the same computer or even the same program on that computer at the same time.
User Interface用戶介面
Command Line Interface (CLI)
1. need less system resource2. difficult to learn and master3. works faster
Graphical User Interface (GUI)
1. easier to learn and master2. consume a lot more system resource3. works slower
Utility Program實用軟件
programs to maintain your computer's health and improve the computers performance.
examples
Anti-virus
Disk Defragmentation
Data Compression
Data Recovery
Encryption
System optimizer
Screen Saver
Driver 驅動程式
programs which helps an OS to communicate and manage a peripheral device.
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.
Word Processing
Database (DBMS)
Spreadsheet
Presentation
Graphics
Sound editing
Communication
System Unit
CPU
Control Unit
Arithmetic Logical Unit
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 is1. faster2. small in capacity 容量較RAM少 (usually measure in MB)3. more expensive
performance factor
clock speed時鐘頻率
Hz
1 instruction cycle
the faster the better
e.g. 2.8GHz
2.8GHz means in a second there are 2.8 billion instruction cycles.
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.
Motherboard
slots
bus 總線
ports 連接埠
USB
PS2
LAN
VGA
DVI
Main memory
RAM
1. volatile - loss data when power off2. store temporary data and instructions to be used by CPU3. upgrade - memory capacity can be changed
ROM
stores:1. S (Basic Input Output System) - a program to be loaded into RAM for checking the computer hardware configuration2. Boot program - a program to start the computerCharacteristics:1. store permanent instruction2. read ony / can't be written3. small in capacity4. non-volatile
CMOS
1. non-volatile2. store system information (e.g. date, harddisk info, RAM info etc)3. data inside it can be updated/ changed.
Peripherals週邊設備
devices other than the system unit
input devices
pointing
mouse
touch pad
track ball
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.
finger print
iris recognition
scanner
barcode reader
output devices
monitor
resolution
The number of pixels can be displayed. There are many standards, for example , VGA, SVGA, XGA etc.
color depth
Number of colors can be displayed. Usually measured in bit. For example, 4-bit color means 2^4 = 16 colors.
pixel
speaker
printer
dpi (dot per inch) - quality
ppm (page per minute) - speed
storage devices
secondary storage
storage devices which are not the main memory all fall into this category.
magnetic
floppy
harddisk
The major secondary storage device.
magnetic tape
Mainly for server backup.
optical
CD
DVD
semi-conductor
flash memory card
CF
SD
Memory Stick
xD
USB thumb drive
units
bit
the smallest / basic computer storage unit. It stores eithe a 0 or a 1.
byte - 8 bits
KB
MB
GB
processing
display / graphic card
sound card