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title=Fundamentals of Data Representation: Error checking and correction

< A-level Computing‎ | AQA‎ | Problem Solving, Programming, Data Representation and Practical Exercise‎ | Fundamentals of Data Representation

UNIT 1 - ⇑ Fundamentals of Data Representation ⇑

← Unicode Error checking and correction Parity bits →

When you send data across the internet or even from your USB to a computer you are sending millions upon millions of ones and zeros. What would happen if one of them got corrupted? Think of this situation: You are buying a new game from an online retailer and put £40 into the payment box. You click on send and the number 40 is sent to your bank stored in a byte: 00101000. Now imagine if the second most significant bit got corrupted on its way to the bank, and the bank received the following: 01101000. You'd be paying £104 for that game! Error Checking and Correction stops things like this happening. There are many ways to detect and correct corrupted data, we are going to learn two.