2.6 Data representation Flashcards
What must all data processed by a computer be in?
binary format
computers and how binary works
a computer processor uses billions of transistors acting s switches, which only act on the binary states on and off
all data and instructions are represented by the binary digits 1 (on) and 0 (off)
representation of data using binary strings
to be processed, instructions and data are converted to binary strings
images and sounds must be digitised and other inputs send binary strings to the processor
units
one unit (a 1 or 0) is called a bit (short for binary digit)
4 bits = 1 nibble 8 bits = 1 byte 1000 bytes = kilobyte 1000 KB = megabyte 1000 MB = gigabyte 1000 GB = terabyte 1000 TB = petabyte
list of units in order
bit nibble byte kilobyte megabyte gigabyte terabyte petabyte
number systems
binary system is base 2 and uses two digits
the denary/decimal system is base 10
hexadecimal system is base 16
place value of binary numbers
2[n] gives the amount of characters in a certain place
2[7] = 128
An image file has a size of 57 600 000 bits.
Express this in megabytes. You may use the decimal prefix 1000 in your calculation [2]
57 600 000 bits / 8 = 7 200 000 bytes
7 200 000 / 1000 = 7200 kilobytes
7200 / 1000 = 7.2 MB
Showing your working, express 1 petabyte in bits.
You may use the decimal prefix 1000 in your answer [2]
8 000 000 000 000 000 bits