Go to
https://books.google.com/books?id=mVQnFgWzX0AC&printsec=frontcover&dq=z80&hl=en&ei=QYeMTuCZJaTu0gHC5MC9BA&sa=X&oi=book_result&ct=result&resnum=1&ved=0CC0Q6AEwAA#v=onepage&q&f=false and skim through Chapter 3. Don't read it too carefully or you'll go blind.
1. Develop your own timing diagram for a memory read that is analogous to the write diagram for picture below. You can use whatever control lines you want.
2. Write a code fragment to add the numbers located in memory addresses 2000H through 2100H using your choice of either Register Indirect or Indexed addressing.
3. Write a code fragment to implement a "square root engine." Suppose the square roots of the numbers from 0 to 5 are stored in memory locations 2000H through 2005H in integer form (i.e., 0, 1, 141, 173, 200, 224 converted to binary). Write the code to read the number that happens to be in memory 1000H, find the square root, and store the result in address 1001H.