1. Binary a. express numbers in binary, binary-coded decimal (BCD), octal and hexadecimal;

2. Binary “There are 10 types of people in the world. Those who understand binary and those who don’t.”

3. Binary Computers use sequences of 0’s and 1’s to represent everything. Text, pictures, videos everything! A = 1000001 These sequences of 0’s and 1’s are called binary. Each individual 0 or 1 is called a bit (short for Binary Digit)

4. Where does Binary come from? Computers are powered by electricity. The current is either: On (1) or Off (0) By rapidly altering the supply of power computers can create sequences of ON,OFF events which we interpret as binary. So ON OFF OFF OFF OFF OFF ON becomes 1000001 or A

5. Groups of Bits 8 bits = 1 byte 1024 Bytes = 1 KB (Kilobyte) 1024 Kilobytes = 1 MB (Megabyte) 1024 Megabytes = 1 GB (Gigabyte) 1024 Gigabytes = 1 TB (Terabyte) 1 byte can be arranged in 2^8 combinations. So it can represent 256 different colours or letters or ….

6. Binary characters There are a few ways of using binary to represent characters the most widely used are ASCII (American Standard Code for Information Interchange) and UNICODE. A = 1000001 B = 1000010 It’s important they lots of people use the same method or you wouldn't be able to communicate.

7. Binary number systems So 10000110 is 128 + 4 + 2 = 134 What is 00000010? 11001100? 1286432168421 10000110

8. Binary Coded Decimal Another way of encoding numbers in binary is to use BCD Binary Coded Decimal. In BCD each number is represented by a 4-bit binary code. 0001 0011 1001 0010 Represents the number 1392

9. Hexadecimal In order to make reading memory contents easier binary digits are sometimes put into 4 bit groups and displayed as Hex. Hex uses BASE 16 to represent the numbers 1-9 and letters A-F.

10. Denary - Binary - Hex DenaryBinaryHexadecimal 111 2102 3113 41004 51015 61106 71117 810008 910019 101010A DenaryBinaryHexadecimal 111011B 121100C 131101D 141110E 151111F 16100010

11. Conversions - Exam questions It is easy to convert between binary and denary and binary and hexadecimal. BUT converting between denary and hexadecimal is a pain. How would you work out how to display the number 179 in Hex? Convert to Binary (10110011) then split into 4 bit sections (1011,0011) the convert to Hex B3

12. Octal Is a BASE 8 number system that can be used instead of Hexdecimal. It also groups digits into 4 bit groups. DenaryOctal 1001 2002 3003 4004 5005 6006 7007 810