Components Of A Personal Computer Flashcards
Computer hardware
Computer organisation
Main physical components of a computer system:
Input/output
CPU
Memory unit
Others: Motherboard Power supply Storage devices Ports and cards
Hardware
Describes the physical components of a computer system which can be categorised as input devices, a CPU, internal and external memory and output devices
Mother board/ system board
A circuit board inside the mirror computers plastic case. It contains integral components including:
CPU chip
Memory chips (RAM and ROm chips)
I/O interface: the channel between the CPU and other devices (keyboard, monitor, etc)
Expansion slots: connectors on the motherboard where expansion cards like display card can be connected
Other logic circuits
Cooling systems
Perform better when kept cool
They are kept cool using active and passive cooling solutions
Active solutions require power while passive don’t
Passive solutions for cooling usually involve reducing the speed at which a component is operating or adding heat sinks to computer chips
E.g. a case fan is an active cooling
CMOS (Complementary metal-oxide-semiconductor )
Attached to the mother board
Its the same as a watch battery or a battery for a remote to your cars alarm system
Keeps the memory for fare and time for BIOS setting
Power supply
A computer uses Direct Current (DC)
Power supply is a device that converts AC (Alternating Current) to DC to run the computer
Power supplies vary in size and Power (in watt)
UPS (Uninterrupted Power Supply) keeps the computer running for a few minutes even when the electricity supply goes off
A desktp PCs powee supply has a fan in it and when you start up the PC, the fan starts up too. The fan pulls hot air out of the power supply and has a side benefit of circulating air through the entire system unit too.
Cards
An expansion device that provides an existing computer with certain added capabilities
Eg
Video/display card: generates the text and graphic images for the monitor while sound card generates sound.
Sound card
I/O card: provide a place for connecting your mouse and printer
Controller card: connects cables of hard disks and floppy disks.
Memory card
Network Interface Card (NIC): a computer circuit board or card that is installed in a computer so that it can be connected to a network.
Ports
Components used as pathways for flow of data. The rear of a PC has many empty holes or external sockets.
Eg
Serial port: used to connect a mouse, modem or scanner
Parallel port: used to connect a printer
Game port: used to connect a joystick while a video port is a connector for the monitor
USB (Universal Serial Bus): can be used to connect many types of input, output and storage devices.
Video Graphics Adapter: the older, analog type used for display
The audio component for plugging in speakers, headphones and microphones. Pink for microphone, green for speakers or headphones and blue for line input.
Central Processing Unit (CPU)
Performance all the processing of input data
It accepts instructions and data and executes them, storing the result in memory
Determines how fast your computer will run and is measured by its Gigahertz (GHz) (Billion instructions per second) or Megahertz (MHz) (Million cycles per second) speed.
Components:
Arithmetic/Logic unit
Control unit
Registers
Arithmetic/Logic Unit
Responsible for all arithmetic operations like additional as well as logic operations such as less than. Logic operations: Evaluates conditions Males comparisons Can compare
Control Unit
Responsible for controlling the transfer of data and instructions among other units of a computer. It manages and controls all units of a computer.
Functions:
Directs and coordinates all operation called for by the program
Activates the appropriate circuits necessary for inputs and output devices
Causes the entire computer system to operate on an automatic manner
Machine cycle: Fetch the instruction Decode the instructions Execute the instructions Store the results
Registers
Holding areas for both data and instructions
Types
For holding data (Data registers)
Hold instructions (instructions registers)
Store logical ststes
Temporary values that serve as increment counters
Small memories inside the CPU They are: Special purpose High speed Temporary storage Located inside CPU
System unit
Houses the primary devices that perform operations and produce results for complex calculations.
Memory unit
Used to store data, instructions and information before, during and after processing by the ALU
Volatile/ dynamic memory: stores data only until the computer is turned off.
Non volatile/ static memory: retains whatever you put in it indefinitely.
Read Only Memory (ROM)
Stores the BIOS (Basic Input Output System) that runs when the computer is powered on
Data and instructions can be read but not modified and instructions are typically recorded at factory.
Its permanent and not erased when the computer is switched off. (Non volatile)
