1. Lesson 3.7 Parity Error Checking
Announcements
Quiz Friday – we will review tomorrow.
The last day for Unit 2 late work is Tuesday, 10/31.
Monday we build our next App.
Lesson 3.7 Parity Error Checking

2. Why is this important? Scenario…
You take an Uber to the movies. The bill that gets charged to your account is supposed to be dollars.
Instead, you are actually billed dollars.
How much were you actually billed?

3. Computers must have a way to check for errors in code that gets sent out.
One way to do this is through even and odd bit parity schemes.

4. Even Parity Scheme The eighth bit is the parity bit:
Makes the number of 1s even.

5. Odd Parity Scheme The eighth bit is the parity bit:
Makes the number of 1s odd.

6. Extra cards are redundant: an extra bit, added to the data to allow us to detect if one of the data bits has been flipped from its original value.

7. What Percent Of Data is Redundant?
5 x 5?
3 x 3?
7 x 7?

8. Another Method ISBN numbers