Topic 1 -Data rapresentation Flashcards
(48 cards)
what is denary
a base 10 number system with 10 digit
why do computers use binary
computers can only undestand binary as it is the simplest language and computers can’t count double figures
what is hexadecimal
it is a number system which uses base 16
As we only have 10 digits, it uses 0-9 and then letters A to F(represent 10 to 15)
why is hex good
Easier to read and interpret
It uses fewer digits to represent the same value
Less likely that digit will be written down incorrectly
how is data processed
using logig gates and stored in registers
what is analogue data and digital data
contineous data, data that has only 2 values
0+0 in binary
0
0+1 in binary
1
1+1 in binary
10
1+1+1 in binary
11
what is an overflow error
result of an addition is too large for the number of bits the computer works with
when will an overflow error occur
if the value is greater than 255 in an 8 bit register
how do you multiply in binary
to multiply by 2 all digits shift one place to the left
how do you divide in binary
to divide by 2 all digits shift one place to the right
conversion from hex to denary
Multiply the left-hand digit by 16, then add the units
Denary to hex conversion
Divide the denary number by 16 to get the number of 16s (the left-hand hex digit)
The remainder gives you the units
Binary to hex conversion
Convert each nibble into its hex value and rejoin
Hex to binary conversion
Split the two hex characters
what are check digits
an additional digit at the end of a string of other numbers designed to check for mistakes in input or transmission
formula for Determining the number of combinations
2n where n = the number of bits
what is a character set
complete collections of characters
what does ASCII stand for
american standard code for infomation interchange
what is each character on keyboard rapresented by?
binary number
what happen when you press a character on the keyboard
number is sent to the CPU which will check the ASCII table
