What logical operation together with what mask can you use to change ASCII codes of lowercase letters to uppercase? What about uppercase to lowercase?                                  ...

What logical operation together with what mask can you use to change ASCII codes of lowercase letters to uppercase? What about uppercase to lowercase?                                                                      What is the result of performing a three-bit right circular shift on the following bit strings: a. 01101010 b. 00001111 c. 01111111