### On a 17 inch monitor, you can see the two slides side by side

1. If the number of 1 bits in a column is 0, 2, 4, 6, 8, etc. then you set the mod 2 sum equal to 0. It is just like even parity in that respect.
2. If the number of 1 bits is odd, i.e. is 1, 3, 5, 7, 9, etc. then you set the mod sum for that column to 1.
Hamming codeword practice questions (see #4, #5, #6 and #7).

Animation of hamming codewords concept.

What if the Hamming codeword for the letter k was received with ONE of the bits being an error and the opposite of what it should be?

1. Suppose that the receiving computer takes the 8 data bits as the ASCII code for a left brace "{" instead of the ASCII code for "k". Can you tell me what bit was wrong when the Hamming codeword was received?

2. Suppose the receiving computer 8 data bits indicate "j" instead of "k". What happened during the data transmission if only one bit was in error?

3. Suppose the receiving computer 8 data bits indicate "i" instead of "k". What happened during the data transmission if only one bit was in error?

4. Suppose the receiving computer 8 data bits indicate "c" instead of "k". What happened during the data transmission if only one bit was in error?

5. Suppose the receiving computer 8 data bits indicate "o" instead of "k". What happened during the data transmission if only one bit was in error? What bit was in error for lower-case o ASCII pattern to be stored in the data bits locations of the ASCII code word? Lower-case O, i.e. little "oh" character "o".

6. Suppose the receiving computer 8 data bits indicate "K" instead of "k". What happened during the data transmission if only one bit was in error and the data bits at locations 12, 11, 10, 9, 7, 6, 5, and 3 indicate an UPPER-CASE "K" instead of a lower-case "k"?

7. CRC example 1 and CRC example 2 and Quiz questions to try out.