others Flashcards
Define memory dump
when memory contents are output to printer/monitor
Uses of binary (3)
ASCII value
unicode value
machine code
Advantages of hexadecimal (5)
easier to understand
easier to debug
shorter = takes up less space
faster to enter than binary
easier to convert from binary than denary
Define simplex data transmission (2)
data transmitted one way only
e.g computer to printer
Define duplex data transmission (2)
data transmitted both ways simultaneously
e.g broadband internet
Define half-duplex data transmission (2)
data transmitted both ways not at same time
e.g walkie talkie
Define serial data transmission (2)
one bit sent at a time over one wire
e.g computer to printer/USB
Define parallel data transmission (2)
multiple bits sent at same time using multiple wires
e.g computer to modem/internal computer components
Advantages of serial (4)
reliable over longer distances
cheaper
data not out of synchronization
less risk of electrical interference between wires
Advantages of parallel (2)
faster transmission
easier to program input/output operations
Features of asynchronous data transmission (3)
data transmitted in agreed bit pattern
data bits grouped together and sent with control bits
receiver of data knows when data starts/ends
Features of synchronous data transmission (5)
continuous stream of data
data accompanied by timing signal
synchronizes sender and receiver
receiver counts number of bits sent
reassembles into bytes
Advantages of synchronous data transmission
faster
Define USB
data transmission method
What ASCII stands for
American Standard Code for Information Interchange
Number of bits in standard ASCII
7 bit codes
Function of ASCII
represent letter/number/characters on keyboard
Denary value for a on ASCII
97
Denary value for A on ASCII
65
Denary value for 0 on ASCII
48
ASCII disadvantages
does not represent non-western characters
Define unicode (2)
coding system
represents characters of all languages
How is sound represented digitally (4)
computer samples sound using ADC
amplitude determined at set time intervals
gives approximate sound representation
sound wave sample encoded as binary
Define sampling
measuring amplitude of sound wave
Define sampling resolution/bit depth
number of bits per sample
Define sampling rate (2)
number of sound samples taken per second
measured in hertz
Benefits of having larger sampling rate/resolution (3)
better sound quality
larger dynamic range
less sound distortion
Disadvantages of larger sampling rate/resolution (3)
larger file size
requires greater processing power
longer to download music files
How do bitmap images work (3)
made of pixels
each pixel represent binary number
binary numbers represent colour
Define colour depth
number of bits to represent each colour
Define image resolution
pixel number in an image
Photos with lower resolution will have higher detail than photos with higher resolution
True or False?
false
Disadvantage of using high resolution images (2)
file size increase
increase in download speed
Define a bit (2)
basic unit of computing memory storage
either 1 or 0
Number of bytes in kibibyte
2^10
Number of bytes in kilobyte
1000
Equation for file size of image
image resolution (pixels) x colour depth (bits)