Chapter 1: Data Representation
Definitions
Binary- Based on the values 1 and 0 only
A Switch ON can be represented by 1
A Switch OFF can be represented by 0
Bit- Abbreviation of binary digit
Byte: A group of eight bits
Nibble- A group of 4 bits
Hexadecimal- A number system based on the value 16
Memory Dump- Used for troubleshooting and debugging, the contents of the RAM output to
the computer screen
Binary-coded Decimal (BCD) - A system which uses nibble represent each denary digit
Packed BCD- Two BCD nibbles stored in one byte
ASCII (American Standard Code for Information Interchange)Code- Primarily used for
characters in the english language, it uses 7-bit binary numbers to represent 128 characters
Character Set- It is all the possible characters a computer can use. Each character has its own
corresponding binary number.
, Unicode- A Coding system that represents all the languages in the world (with the 1st 128
characters the same as ASCII)
Denary Numbers- Decimal numbers that are written using 0,1,2,3,4,5,6,7,8,9 for each denary
digit.
Decimal Prefix- Includes kilo, mega, giga and tera representing factors of 103, 106, 109 and 1012
respectively.
Binary prefix- Includes kibi, mebi, gibi and tebi representing factors 210, 220, 230 and 240
respectively
Overflow- When the result of a calculation is too large to fit into the number of bits for
storage in a system.
One’s complement- Each 0 is switched to 1 and vice-versa
Two’s complement- The one’s complement of a binary number, plus 1
Register- A small hardware component in the CPU where information is stored temporarily
Definitions
Binary- Based on the values 1 and 0 only
A Switch ON can be represented by 1
A Switch OFF can be represented by 0
Bit- Abbreviation of binary digit
Byte: A group of eight bits
Nibble- A group of 4 bits
Hexadecimal- A number system based on the value 16
Memory Dump- Used for troubleshooting and debugging, the contents of the RAM output to
the computer screen
Binary-coded Decimal (BCD) - A system which uses nibble represent each denary digit
Packed BCD- Two BCD nibbles stored in one byte
ASCII (American Standard Code for Information Interchange)Code- Primarily used for
characters in the english language, it uses 7-bit binary numbers to represent 128 characters
Character Set- It is all the possible characters a computer can use. Each character has its own
corresponding binary number.
, Unicode- A Coding system that represents all the languages in the world (with the 1st 128
characters the same as ASCII)
Denary Numbers- Decimal numbers that are written using 0,1,2,3,4,5,6,7,8,9 for each denary
digit.
Decimal Prefix- Includes kilo, mega, giga and tera representing factors of 103, 106, 109 and 1012
respectively.
Binary prefix- Includes kibi, mebi, gibi and tebi representing factors 210, 220, 230 and 240
respectively
Overflow- When the result of a calculation is too large to fit into the number of bits for
storage in a system.
One’s complement- Each 0 is switched to 1 and vice-versa
Two’s complement- The one’s complement of a binary number, plus 1
Register- A small hardware component in the CPU where information is stored temporarily
