Once Upon A Z80

Readings from the Z80 user's manual
Due February 11, 2008

We know enough now that we can start to use the Z80 user's manual and connect it with what we are doing in class. Below is a guide to what we have covered in class and how it is referenced in the book. Please read and make sure that you understand the following from the manual. If you have any questions, email the list:

• Registers, ALU: (pages 22 -26)
  • The Gameboy does not have the alternate register set, nor does it have IX or IY. We have covered the others, except I and R.
  • R is used for refreshing dynamic RAMs --- not relevent for assembly language programming. We will ignore it for this class
  • I will be covered when we introduce interrupts. Don't worry about it for now.
• Flag register (pg. 76)
  • focus on the carry flag and the zero flag. You won't make as much use of the others.
• Opcodes: (don't worry about T states and M cycles. This is timing and we will get to it soon. Make sure you understand the condition bits affected.)
  • NOP (pg 172)
  • DEC (pg 164, 187)
  • INC (pg 160, 184)
  • LD (pg 82, 83, 86, 89, 92-97, 102, 105-106, 109-110, 113)
  • JP, JR (pg. 238 - 250)
  • PUSH (pg 116)
  • POP (pg 119)
  • CALL (pg. 255-257)
  • RET (pg. 260-261)
  • CP (pg. 158)
• addressing modes (pg. 44-48) :
  • Here on the ones we have covered: Immediate, Immediate extended, Relative (as in JR), Extended, Register and Register Indirect