Encoding and Sending Formatted Text Binary  Text

The Internet is powerful We send text over internet – how? We know that we only send bits over the internet… We need a way to encode text with bits If it were up to you, how would you encode text in binary? (Just an outline to the structure – not detailed)

Review We explored how to encode numbers in binary, and we also developed protocols for sending a list of numbers. Today we’re going to take that method one step further and look at how we can encode text with a binary representation. if we can figure out a way to represent information as a set of numbers, then we can encode it in bits and store that information in a computer or send it over the Internet. Your task was to attempt to come up with a protocol for translating decimal into text – we did not use the ASCII key, but rather you and your partner had to come up with you own method. The Code.org internet simulator translated binary to decimal to text (ASCII) for us, but how would we send messages with bold, italics, color, underline, etc.?

Text ASCII (“Ask-Key”) American Standard Code for Information Interchange Originally 7 bits long – so only 128 possible values 0-31 are control characters (defunct) 32 – 126 are printable characters (0-9, alphabet, punct.) 127 – delete Standard 8 bit When I mention “7 bits long” or any other number of bits, the reason we need to know this is because the number of bits determines how large a number we can express in decimal. Think of it this way: for every bit, we can roughly double the amount of numbers we can express in decimal. One bit (0 or 1) – we can express only two numbers in decimal (0 or 1) Two bits (00 – 10) we can express four numbers in decimal (0 - 3) Three bits (000 – 111) we can express eight numbers in decimal (0 – 7) Four bits (0000 – 1111) we can express sixteen numbers in decimal (0 – 15) * Remember to count zero as one of the numbers we can express… so 0-3 is actually 4 numbers. Aside from why we convert binary to decimal for representing text using ASCII – we (we will study this later but… the amount of bits is important when determining IP addresses [ again, just foreshadowing. We haven’t learned this yet])