computer systems Flashcards
(36 cards)
how to work out range of values in twos complement
-2⁸-¹ to (2⁸-¹)-1
twos complement from negative denary
find positive number
flip 1’s and 0’s
flip 1’s and 0’s from right most 0
twos complement from binary
flip 1’s and 0’s
flip 1’s and 0’s from right most 0
determining whether exponent positive or negative
mantissa decimal moved left = positive
mantissa decimal moved right = negative
side of padding of floating point representation
sign- 1 bit
mantissa- 15 bit
exponent- 8 bit
what does the mantissa determine?
dictates precision of a number
more bits allocated, more precise number
what does the exponent determine?
dictates range of numbers that can be represented
more bits added, bigger the range
increased mantissa, decreased exponent means…
increased precision
decreased range
decreased mantissa, increased exponent means…
decreased precision
increased range
disadvantage of extended ASCII
only 8 bit code meaning maximum of 256 characters can be represented
3 advantages of unicode
16 bit code per character with maximum of 65,536 characters
first 128 characters of unicode are identical to ASCII, allowing for compatibility
universally accepted by computing platforms
disadvantage of unicode
uses more storage space per character for non- ASCII characters
advantage and disadvantage of bitmapped graphics
great for representing realistic images
images become blurred (pixelated) with scaling
advantage and disadvantage of vector graphics
not blurred by scaling
cant create photo realistic images very well
4 factors that can improve performance of computer system
number of processors (cores)
width of data bus
cache memory
clock speed
how can the number of processors improve performance of a computer system?
more cores a processor has, more sets of instructions the processor can receive and process at the same time
how can the width of data bus improve performance of a computer system?
increasing data bus from 32 to 64 bit means computer can transfer twice as much information in a single operation
how can cache memory improve performance of a computer system?
more cache memory, the more data that can be stored closer to the CPU, providing faster access time
how can clock speed improve performance of a computer system?
higher the clock rate, the faster the computer may complete
fetch execute cycle
(memory read operation)
processor sets up address bus with required address
processor activates READ line on control bus
address on RAM is located and opened, instruction put onto the data bus
instruction then interpreted by decoder and executed
fetch execute cycle
(memory write operation)
processor sets up address bus with required address
processor activates WRITE line on control bus
address on RAM is located and opened
instruction to be written is loaded onto data bus, sent to the RAM and stored
3 ways heating systems are energy efficient
remote control settings allows heating to be changed outside the home
adjusts heating depending on room usage
can be adjusted in comparison to weather
3 ways traffic control systems reduce effect on environment
smart traffic lights
smart motorways
satellite navigation
2 car management systems that reduce the effect on the environment
start stop systems
engine control units
