H a r d w a r e  

FAQ

There are four main components of the hardware of a computer:

• Input devices
• processor
• output devices
• storage devices

CPU and Memory

CPU: Contains electronic circuits, should transfer "data" into "information".
Microprocessor chip for PCs.

Computer memory or primary storage, RAM: holds data temporarily before, during or after processing by the CPU. Holds also the programs needed by the CPU.

Peripheral devices

• input devices
• output devices
• secondary storage

Input devices

• mouse
• keyboard
• scanner/bar code reader
• microphone
• touchscreen/touchpad
• digital camera

Output devices

• monitor
• printer
• speaker
• beamer

Secondary storage

like floppy disk, hard disk, CD, ...

Difference between primary and secondary storage

• primary storage (memory):
  • most of it is RAM: volatile, limited, very quick access.
  • only part of it is ROM (non-volatile)
• Secondary storage: non-volatile, unlimited, "slow" (several milliseconds) access.

Secondary storage may be

• "random access" like magnetic disk (hard disk, diskette, CD), or
• "sequential access" (magnetic tape).

Classification of Computers

• Supercomputers
• Mainframes,
• Minicomputers, Workstations
• PCs
• Notebooks, Laptops
• ......