A Description of Computers
Data
Bit- each individual ‘1’ or ‘0’ is a bit-short for binary digit.
Byte- 8 bits are a byte.
Kilobyte-is 1000 bytes (1024)
Megabyte-is 1,000,000 bytes
Gigabyte-is 1,000,000,000 bytes
Each character on keyboard-8 bit
Computer systems v Manual systems
Benefits of computer system:
Takes up less space
Searching is very quick
More than one person can access the same data form their network PC.
The data stays in the computers memory
Fewer staff are needed to look after a computer system
Reports can be generated very quickly-automated
Problems of a computer system:
Setting up is very expensive
Computer systems need people to maintain them
POWER CUTS!
It is easy to hack into a computer system.
Types of computer
Mainframes-biggest
They are the most powerful
They are very large
VERY expensive
They are used in BIG businesses-banks, insurance companies.
Minicomputers-middle
Less powerful than mainframe but more powerful than micros
Microcomputers-most common-usually called PC’s.
Are designed to stand alone
Much less powerful than mainframes.
Networks-LANS AND WANS
Local area network-LAN-small-offices and schools.
Wide area network-WAN-large-link together different places.
Advantage of using networks-peripherals such as printers can be shared amongst several users.
Software can be shared amongst several users.
Communication across network is fast + cheap
Disadvantage of using networks-cabling can be expensive to install and replace
A fault with the server will prevent the whole network from working
Security measures are needed to restrict access to network
WANS are vulnerable to hackers and viruses.
'Networks-security
SERIAL NUMBERS
ALARMS
DOORS
FIRE PROTECTION
LOCK
AVOID
BLINDS
JUST REMEMBER SADFLAB
Passwords-should be changed frequently.
Backup-and files should be kept secure-in locked fireproof rooms.
Input devices
Keyboards
Mouses-touchpad, tracker balls.
Graphics pads make drawing easier and more
Bit- each individual ‘1’ or ‘0’ is a bit-short for binary digit.
Byte- 8 bits are a byte.
Kilobyte-is 1000 bytes (1024)
Megabyte-is 1,000,000 bytes
Gigabyte-is 1,000,000,000 bytes
Each character on keyboard-8 bit
Computer systems v Manual systems
Benefits of computer system:
Takes up less space
Searching is very quick
More than one person can access the same data form their network PC.
The data stays in the computers memory
Fewer staff are needed to look after a computer system
Reports can be generated very quickly-automated
Problems of a computer system:
Setting up is very expensive
Computer systems need people to maintain them
POWER CUTS!
It is easy to hack into a computer system.
Types of computer
Mainframes-biggest
They are the most powerful
They are very large
VERY expensive
They are used in BIG businesses-banks, insurance companies.
Minicomputers-middle
Less powerful than mainframe but more powerful than micros
Microcomputers-most common-usually called PC’s.
Are designed to stand alone
Much less powerful than mainframes.
Networks-LANS AND WANS
Local area network-LAN-small-offices and schools.
Wide area network-WAN-large-link together different places.
Advantage of using networks-peripherals such as printers can be shared amongst several users.
Software can be shared amongst several users.
Communication across network is fast + cheap
Disadvantage of using networks-cabling can be expensive to install and replace
A fault with the server will prevent the whole network from working
Security measures are needed to restrict access to network
WANS are vulnerable to hackers and viruses.
'Networks-security
SERIAL NUMBERS
ALARMS
DOORS
FIRE PROTECTION
LOCK
AVOID
BLINDS
JUST REMEMBER SADFLAB
Passwords-should be changed frequently.
Backup-and files should be kept secure-in locked fireproof rooms.
Input devices
Keyboards
Mouses-touchpad, tracker balls.
Graphics pads make drawing easier and more