Hardware Flashcards
Expand CPU
Central Processing Unit
What is CPU often referred to as?
Brain of the computer
Explain Fetch-execute Cycle
A computer process that locates a program instruction from internal memory, decodes the instruction and carries out the action required; this process is then repeated for the rest of the program instructions.
What are the three main components of CPU
Control Unit
Arithmetic and logic unit
Immediate access store
Explain Control Unit
Manages the execution of instructions one at a time using fetch execute cycle
What are the three jobs of Control Unit
1) decide which instruction to carry out next and fetch it from memory
2) To decode the instruction
3) to execute the instruction
Explain ALU
This component carries out arithmetic calculations to be carries out(+ - * /)
Perform logical comparison such as ‘And’ and ‘NOT
Explain Immediate access store (IAS)
This component stores all programs and data temporarily while they are in use
Explain the steps in Fetch Execute Cycle
1)The processor check the program counter to see which instruction to run next
2) the program counter gives an address value in the memory of where the next instruction is
3) The processor fetches the instruction value from its memory location
4) Once the instruction has been fetches, it needs to be decoded and executed
5) Once this is complete, the processor goes back to the program counter to find the next instruction
6) This Cycle is repeated until the program ends
What is Fetch-Execute cycle?
Fetching instruction from its memory and executes it
What is a Program counter?
The Program counter is the CPU register that stores the address( memory location reference) for the next instruction to be fetches
Expand MDR
Memory Data Register
Expand MAR
Memory Address Register
What is MDR
MDR temporarily stores data being fetched from or written to the main memory of the CPU
What is MAR
MAR Temporarily stores current instruction or data
What is an Instruction Register
Stores the current instruction to be decoded and then execution
What is an Accumulator
When calculations take place on data, the results are initially stored on accumulator before transferred and stored in the main memory
What are the factors that influence the speed of processing
Clock Speed
Cache
Processor Core
3 Types of Internal memory
RAM
ROM
Cache
Expand RAM
Random Access Memory
Expand ROM
Read Only Memory
Explain RAM
Can be read from or written
Volatile
used to hold programs and data that are currently being used(operating System)
Explain ROM
Non Volatile
Can be read but not written
Used to store programs that are frequently required by the computer ( boot program)
Explain Cache
Temporarily stored frequently used instructions and data
Quicker to store cache memory as it has a smaller storage capacity compared to RAM
What does Volatile Mean?
Means if the computer is closed then reopened, the RAM would stay open
Factors that influence the speed of processing
Clock Speed
Cache
Processor Core
Explain Clock Speed
Indicator of the speed at which the CPU can operate
Measurement of Clock Speed
Gigahertz( GHZ)
What does GHz represent?
The number of instruction cycles the CPU can deal with in a second
How to measure computer power?
Clock Speed
Explain Processor Core
Defined as a single processor with its own control unit, ALU and registers
What are Peripheral Devices?
Devices that are connected to the computer externally, including input, output and external storage devices
What are input devices?
hardware components which can be used to enter/pass data into the computer system
What are output devices?
Devices that are used to view output
What are keyboards, mouse and webcams?
Input devices
Explain Microphone
1) Accepts sound input or human voice into a computer system
2) A voice recognition system can covert sound to text
Advantages of Microphone
1) Relatively Cheap
2) People can speak faster than they type, so it is cheaper than a keyboard
Disadvantages of Microphone
1) Can have have limited battery life
2) Background noise can interfere with spoken words
Explain Mouse
1) A mouse has finger operated buttons
2) When these buttons are clicked they perform an action
3) Can also control the movement of cursor on the computer
Advantage of a Mouse
1) Easy to use
2) Can replace complex keyboard commands
3) Highly Accurate
Disadvantage of a Mouse
1) Can only be used in a flat and smooth surface
2) can easily be broken
Explain Graphic Digitiser
Consists of a flat surface where you can use a pen to write or draw with
As you draw on the surface, the image will appear on the screen
Used by architects
Advantages of a Graphic Digitizer
1) Enables the user to draw naturally
2) The stylus pen can be used as the same way as a pen
Disadvantages of a Graphic Digitizer
1) Much more expensive than a mouse
Explain Touch Screen
1) Works by using your finger to touch the screen
2) the touching is detected and is translated into instructions
Advantages of a Touch Screen
1) Easy to use as you don’t need excellent ICT skills to operate
2) Cheaper as you don’t need to purchase other peripherals such as mouse or keyboard
Disadvantages of a Touch Screen
1)Not suitable for inputting large amount of data
2)Can easily become dirty
Explain Speakers
Uses audio signals and then converts it into sound
Advantages of Speakers
1) Useful for visually impaired users
2) Natural ways to communicate with users
Disadvantages of Speakers
1) Good quality speakers tend to be expensive
2) Can disturb others in the room
Explain Laser Printer
1) A laser beam is used to scan the image of the page to be printed onto a drum by building a pattern of static electricity
2) This attracts toners (Printer Ink) to reproduce the page
Advantages of Laser Printer
1) Produces High Quality Prints
2) Prints very quickly
Disadvantage of Laser Printer
1) Produces shiny images
2)More suited for text printing
Explain 3D Printer
Gradually prints a solid 3D object one layer at a time
Advantages of 3D Printer
1) Time taken to produce an object is much faster that using conventional methods
2) Can print an a variety of surfaces
Disadvantage of 3D Printer
1) Limited form of printing as it can only print a prototype (not full scale)
2) Not economical for large-scale manufacturing
Explain Hard disc drive
1) Consists of a number of rigid discs stacked on a spindle and enclosed in a sealed unit
2) Formatting a disc divides the surface into a number of tracks and sectors
3) As the discs rotate at high speeds the read/write heads move back and forth across the surface
Advantages of Hard disc drive
1) The cost per gigabyte is cheaper than other forms of external storage
2) Storage capacity is much greater compared to solid-state storage devices
Disadvantage of Hard disc drive
1) Due to moving parts, such as read/write heads, they are prone to breaking down
2) Access speeds are slower than ‘flash’ memory devices
What are storage devices?
Pieces of equipment that store all the data in the computer
