1. Working with text ASCII and UNICODE

2.  0 1 1 0 0 0 0 1  0 1 0 0 0 0 0 1  0 0 1 1 0 0 0 0

3. From the CAS curriculum KEY STAGE 3  Representations of:  Unsigned integers  Text. [Key point: each character is represented by a bit pattern. Meaning is by convention only. Examples: Morse code, ASCII.]  Sounds [both involving analogue to digital conversion, e.g. WAV, and free of such conversion, e.g. MIDI]  Pictures [e.g. bitmap] and video.  Many different things may share the same representation, or “the meaning of a bit pattern is in the eye of the beholder” *e.g. the same bits could be interpreted as a BMP file or a spreadsheet file; an 8-bit value could be interpreted as a character or as a number].

4. Today’s session 5:00 – 6:00 Computers and text 6.00 – 7.00 Programming in Scratch

5. Encoding and decoding See Boston University CS101 presentation – go to first lecture (whole series is good!) Boston University CS101 presentation An excellent introduction to Computer Science and what a bit pattern might mean

6. 1010001100000011010000000111011110110010100111110 011101111011 0000000100100011011101010110010111010 000010100110000001001011 1010110100100100111110010 111100011111000000010000110001110110 0011001100110 001110110110101110110110001100001110100110001011 0 101001111000010001101010001001011111101001010000111010010000 11010011111010111010001110010011000010 10010001100011011010010 00011010001000010100000101010101110000001011001000110010010110 01000100011111100000110111010111001101110110011001111110011101 11010100010101010110011111011111000000100011001111110010000111 1000110001101111001011110010100001101 100111110110100011001101 10110011101010001111001010001001010110111101011000101011110100 01010101101101001110001111011010011011010100101010011101110000 00111001010110010010010011001111001110111111100100101101001110 10011011011010010101011010111010011011011000010101000001001101 01001111001110111001110111100101011110011110011001101010110000 0010010110 001100010101001110110000000101000011001010101001100 01011011011111001100100001001101110011000011010 01011101010001 00101010110110101001010111010110000111011110010101100011100000 00010110000011101101110101000011111001110000010111000001001011 10011111111011111110001110111100000000101000011110100101001001 111010101100001001000111011011100010000010010 0111011000101000 111000000001111011011111101110101 0100011001000000100000010000 100100000011111001101 1010101110101101000110000101001010110110 Text?

7. 1010001100000011010000000111011110110010100111110 011101111011 0000000100100011011101010110010111010 000010100110000001001011 1010110100100100111110010 111100011111000000010000110001110110 0011001100110 001110110110101110110110001100001110100110001011 0 101001111000010001101010001001011111101001010000111010010000 11010011111010111010001110010011000010 10010001100011011010010 00011010001000010100000101010101110000001011001000110010010110 01000100011111100000110111010111001101110110011001111110011101 11010100010101010110011111011111000000100011001111110010000111 1000110001101111001011110010100001101 100111110110100011001101 10110011101010001111001010001001010110111101011000101011110100 01010101101101001110001111011010011011010100101010011101110000 00111001010110010010010011001111001110111111100100101101001110 10011011011010010101011010111010011011011000010101000001001101 01001111001110111001110111100101011110011110011001101010110000 0010010110 001100010101001110110000000101000011001010101001100 01011011011111001100100001001101110011000011010 01011101010001 00101010110110101001010111010110000111011110010101100011100000 00010110000011101101110101000011111001110000010111000001001011 10011111111011111110001110111100000000101000011110100101001001 111010101100001001000111011011100010000010010 0111011000101000 111000000001111011011111101110101 0100011001000000100000010000 100100000011111001101 1010101110101101000110000101001010110110 Sound?

8. 1010001100000011010000000111011110110010100111110 011101111011 0000000100100011011101010110010111010 000010100110000001001011 1010110100100100111110010 111100011111000000010000110001110110 0011001100110 001110110110101110110110001100001110100110001011 0 101001111000010001101010001001011111101001010000111010010000 11010011111010111010001110010011000010 10010001100011011010010 00011010001000010100000101010101110000001011001000110010010110 01000100011111100000110111010111001101110110011001111110011101 11010100010101010110011111011111000000100011001111110010000111 1000110001101111001011110010100001101 100111110110100011001101 10110011101010001111001010001001010110111101011000101011110100 01010101101101001110001111011010011011010100101010011101110000 00111001010110010010010011001111001110111111100100101101001110 10011011011010010101011010111010011011011000010101000001001101 01001111001110111001110111100101011110011110011001101010110000 0010010110 001100010101001110110000000101000011001010101001100 01011011011111001100100001001101110011000011010 01011101010001 00101010110110101001010111010110000111011110010101100011100000 00010110000011101101110101000011111001110000010111000001001011 10011111111011111110001110111100000000101000011110100101001001 111010101100001001000111011011100010000010010 0111011000101000 111000000001111011011111101110101 0100011001000000100000010000 100100000011111001101 1010101110101101000110000101001010110110 Image?

9. Text Data  Are sets of characters  Characters could be letters, digits, symbols (£, &),  Telephone numbers are text data (should be encoded as text)

10. Morse Code  Morse code is one kind of coding system for text  Try these activities: http://ascii-table.com/morse- code.php http://www.youtube.com/watch?v= Lki3jxNLVCI http://invigorate.royalsociety.org/ks3 /keeping-secrets/codes-and-code- breaking.aspx

11. ASCII code – another coding system for text. Used by computers space010000000110000A1000001a1100001 !010000110110001B1000010b1100010 "010001020110010C1000011c1100011 £010001130110011D1000100d1100100 $010010040110100E1000101e1100101 %010010150110101F1000110f1100110 &010011060110110G1000111g1100111 '010011170110111H1001000h1101000 (010100080111000I1001001i1101001 )010100190111001J1001010j1101010 *0101010:0111010K1001011k1101011 Note how the codes for A.. Z, a.. Z and 0.. 9 are sequences

12. ASCII & Unicode  ASCII uses 7 bits to encode characters  Extended ASCII uses 8 bits  Unicode uses 8, 16 or 32 bits and is usually shown in Hex. 16 bits is the most common system used.

13. ASCII codes are a subset of Unicode Unicode uses the same code for A

14. Explore the ASCII codes using the Insert Symbol option in MS Word What different alphabets are there? Note the character code can’t be represented in 1 byte

15. Now try…  James Robinson’s Binary Messaging System James Robinson’s Binary Messaging System  Can you create your name in ASCII?  Good for binary practice as well as understanding ASCII coding