components

Created by

Afton Abraham

Cards (48)

what is the purpose of a computer
to take data, process it, then output it
what is an embedded system
computers built inside a larger system for a specific purpose
what are advantages of embedded systems
-easier to design
-cheaper to produce
-more efficient at doing a specific task
what determines the processing power of a CPU
-clock speed
-number of cores
-cache size
what does the CPU do
acts as the brains of the computer: processes all data and instructions that make the system work
what is the role of the control unit
-controls the fetching, decoding and execution of program instructions(FDE cycles)
-controls the flow of data inside and outside the CPU
what is the role of the arithmetic logic unit
-in charge of doing all the mathematical and logical operations such as AND, OR and NOT/addition, subtraction
what is the role of the cache
-very fast memory that stores frequently/ recently used instructions
-helps CPU access instructions faster
-ordered in levels 1-3; level 1 is the quickest but has the lowest capacity whilst level 3 is the slowest but has the highest capacity
-expensive compared to RAM
what is the role of registers
holds temporarily tiny bits of data need by the CPU
what is the role of the MAR(memory address register)
holds any memory address of data/instruction currently going to be executed by CPU
what is the role of the MDR(memory data register) 
holds the actual data/instruction which may have been fetched from memory or is going to be written to memory
what is the role of the program counter
holds the next memory address of the instruction to be executed for each cycle
what is the role of the accumulator
stores results of calculations performed by CPU
describe the fetch execute cycle
1.copy memory address from program counter to MAR
2.copy memory instruction stored in MAR address to MDR
3.increment program counter to point to the address of the next instruction
4.instruction in MDR is decoded by the control unit
5.instruction is then executed which could include loading data from memory or writing data to memory
what is the difference between volatile and non volatile memory
-volatile memory is memory that is temporary requiring power
-non volatile memory is memory that is permanent keeping content when no power is available
what type of memory is RAM
high speed, volatile memory
what is RAM 
-acts as the main memory in computer
-files and operating systems are copied from secondary storage to RAM
-Ram is slower than CPU cache but faster than secondary storage
what is virtual memory
-secondary storage used as extra RAM
-used when RAM is full and stores data not recently used or too many apps open
-is considered slow
what is ROM 
-non volatile memory
-contains instructions needed for computer to properly boot up(known as BIOS)
what is clock speed
-the number of instructions a single processor core can carry out per second
-higher clock speed=greater number of instructions carried out per second
what are the downsides of overclocking
CPU can overheat
what is a core in a CPU
an independent processing unit which can process data and execute instructions
how does having more cores affect performance
more cores leads to more instructions that can be carried out
how does cache size affect performance
larger cache size means CPU can access more data needed to be processed faster
how does more RAM affect performance
-more RAM leads to a faster/smoother system due to not needing to use virtual memory
what is the role of a GPU
specialised circuits in charge of graphics and image processing for CPU
what is the difference between primary and secondary storage
-primary storage is memory areas CPU can access very quickly that is mostly volatile
-secondary storage is non volatile memory where data is stored when not in use making them slower
what is a hard disk drive
-internal storage in pc's
-made up of magnetised metal disks that spin thousands of times so data stored magnetically
-movable arm allows data to be accessed and read or write it
-long lasting and reliable
-portable
what is a solid state drive
-storage device with no moving parts
-fast and reliable
-portable
-hybrid drives use SSD for OS and programs and hard disk for data
advantages and disadvantages of SSD
-fast
-no need for defragmenting
-shock proof
-silent
-expensive
-only written certain number of times before deterioration
advantages and disadvantages of HDD
-cheap
-high capacity
-long read/write life
-noisy
-slower
what are optical discs
-cheap and robust secondary storage
-include things like CD, DVD and blue ray(in order of capacity)
-streaming services removed need for this
advantages and disadvantages of optical discs
-cheap
-portable
-not damaged by water
-low capacity
-slow read/write times
-poor reliability
what are magnetic tapes
-comes in plastic cassettes containing reels of tape
-needs special tape drive for read/writing
-used by large organisations
-tape is read from beginning to end or stopped by computer
advantages and disadvantages of magnetic tape
-very cheap
-fast read/write speed
-high storage capacity
-very slow when finding specific data
ranking of secondary storage
fastest: SSD
slowest: optical disk
priciest: SSD
cheapest: magnetic disk
highest capacity: magnetic tape
lowest capacity: optical disk
what is the role of the operating system
-manages hardware and runs software
-provides user interface
-deals with file management and manages system security
what do device drivers allow
allows the communication of operating systems and internal hardware
what is the use of a user interface
allows user to interact with computer system
what is the role of a graphical user interface(GUI) and command line interfaces
-graphical user interfaces allow visual and interactive interfaces for users everyday
-command line interface is text based making them less resource heavy but can also be more efficient and powerful for advanced users