Instructor Notes

March 10, 2008

---

Assignment Reminders

• Initial Project Proposal was do yesterday at midnight
• Midterm: March 12
• Hello Noise: March 25th
  • focus on sound effects for the games

midterm review

• DAA

• JR. Example:

  Mem Loc     Hex            Op Code
  0351        18 01          JR $0354
  0353        00             NOP
  0354 

• indirect addressing
• EQU, db
• review of the generic qualities of labels
• jp [hl]
• ldi a,[hl] = ld a,[hl+]
• ldh vs. ld
• bit, set, reset, shifts and rotates (see upper right hand corner crib sheet page 1.
• carry flag
• bit mask
• T states and M cycles

Test Questions

1. Write something that will do a simple task.
   • I give you all the comments but not the opcodes
   • make sure you understand how the tiles relate to ASCII for this one
   • uses DAA
   • understand swap, bit masks
2. hand-assemble some code.
3. calculate how long something takes to execute
   • understand the distinction between T states and M cycles.

   • Know how to read the GameBoy crib sheet for this information

4. Write a simple routine to do simple 16-bit integer arithmetic
5. Show you understand the distinctions of labels, EQU, DB, etc.
   • You will be given two very small snippets of code and asked if they perform their intended function.
6. Verbatim from the exam:

   • hello-broken.asm is hello-sprite.asm with some lines changed from the original and shown in bold.

     • Compare hello-broken.asm with hello-sprite.asm. For each changed line, write if the altered code will still operate with the same functionality as the original.
     • If the altered line breaks the code or significantly alters its functionality, explain why. If the altered line does not significantly change the functionality, explain why not.
     • Show in your answers that you understand the functionality of both the original and the altered lines. An example correct response for a specific line might be “This line breaks the code. We need to load register a into the contents of the memory location pointed to by 16-bit register pair hl, rather than the value of register hl itself.” In contrast, a correct observation but incorrect response would be “line should read ld [hl],a instead of ld hl,a.” This latter response does not show that you understand the function of the original code and the function of the altered code.

7. Construct a simple macro. I give you hello-sprite.inc to remind you of macro syntax

Questions you might have

• Ascii and tile maps
• hand assembly