computer systems Flashcards
What is hardware?
the physical components of a computer system e.g.hardrive
What is software?
the non-physical components of a computer system e.g.applications
What is application software?
programs that help the user perform specific tasks e.g.word processor
What is system software?
software used to control the computer and run applications e.g.OS
What is utility software?
helps maintain the system e.g.encryption
What is volatile memory?
memory where data is lost when the computer is shut down
What is ROM?
read-only memory
non-volatile
What is RAM?
random-access memory
volatile
What is virtual memory?
volatile memory created in storage drive temporarily
What is memory?
has short term memory
What is storage?
location for saving and accessing data on a long-term basis
What is the CPU and what does it do?
the central processing unit which controls the computer
How can you improve CPU performance?
Cores- more cores means multiple instructions can be processed at once
clock speed- higher clock speed means more pulses per second and data is processed faster
What is the fetch, decode and execute cycle?
fetch- control unit reads memory address, instruction stored in that address,memory address incremented
decode-instruction from memory decoded and control unit prepared
execute- carries out process
What are the 3 levels of cache?
L1-stored in CPU
L2-traditionally outside CPU now stored in the CPU
L3-stored in chip between CPU and memory
How do magnetic disks work?
use magnetic fields to magnetise individual sections off a metal spinning disk.
How do optical disks work?
use a laser to scan the surface of a spinning disk
How does solid state work?
can be used as external secondary storage
What are the advantages of magnetic disks?
large storage capacity faster than optical disks power not required to retain data cheap easily replaced
What are the disadvantages if magnetic disk?
moving parts will eventually fail crashes can lead to loss of data fragile high power consumption can be noisy
What are the advantages of optical disk?
easy to store portable wide compatibility east to use can last a long time
What are the disadvantages of optical disk?
data on write-once discs permanent require special drive to read and write cost of storage is high easily broken longevity not confirmed
What are the advantages solid state?
read speeds faster than normal hard disk drives power not required to retain information lightweight and durable no moving parts require less power and are silent
What are the disadvantages of solid state?
limited storage capacity
write speeds can be 4x slower than magnetic disks
cost per unit storage is higher than magnetic drives
information can only be modified a certain amount of times
What is cloud storage?
storage over the internet, stored in multiple different servers
What is an embedded system?
a computer system with a purpose inside a larger mechanical system
What are the advantages of cloud computing?
unlimited storage capability
automatic back ups
universal access
device independence
What are the disadvantages of cloud storage?
requires reliable internet connection requires high bandwith slower to access than local files user doesn't have control over their own data less safe
What are the advantages of embedded systems?
cheaper to design and build
require less power
can be built using cheaper, less powerful processors
What are the disadvantages of embedded systems?
Difficult to upgrade
hardware is limited
hard to maintain
difficult to backup embedded files
What does user interface do?
allows a user to interact with a computer
What does processor management do?
allow more than one program to run simultaneously
What does memory management?
manages memory so that more than one program can run at the same time and more than one document can be opened at the same time
What is applications management?
it allocates memory space and determines time needed by a processor for an application to run
What is the Von Neumann model?
all instructions and data stored in the same memory in binary
instruction follow fetch, decode and execute cycle serially
What are the advantages of the von neumann model?
easier to program computers
no need to rewire computer circuits
simplifies hardware
Why would you use a solid state drive?
What does the bus do in Von Neumann?
transmits data from one part of the computer to another
What does the arithmetic logic unit in Von neumann?
allows arithmetic and logic operations to be carried out
What does the control unit do in Von neumann?
controls the operation of the ALU, memory and input/output devices
What does the register do in Von neumann?
high speed storage areas in CPU where data must be stored before it can be processed
What does the clock do in Von neumann?
every clock cycle an instruction is fetched from the memory, decoded then executed on the ALU
How do you convert from MB to GB?
1 mb = 0.001 gb
How is data stored on a hard disk drive?
stored in binary code
Why would you use a solid state drive?
accessing data- flashdrive
