Computer System電腦系統

System sofware refers to programs which make your computer works.

Functions:1. allocate system resource2. manage files3. monitor activites

be able to handle ONE task at a particular time.

be able to handle multiple tasks at the same time.

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

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

1. need less system resource2. difficult to learn and master3. works faster

1. easier to learn and master2. consume a lot more system resource3. works slower

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

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

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

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

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

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.

1. volatile - loss data when power off2. store temporary data and instructions to be used by CPU3. upgrade - memory capacity can be changed

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

1. non-volatile2. store system information (e.g. date, harddisk info, RAM info etc)3. data inside it can be updated/ changed.

devices other than the system unit

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.

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

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

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

The major secondary storage device.

Mainly for server backup.

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