{{Chris Tyler DraftAdmon/important|This lab is not used in the current semester.|Please refer to the other labs in the [[:Category:SPO600 Labs|SPO600 Labs]] category.}}[[Category:SPO600 Labs- Retired]]{{Admon/lab|Purpose of this Lab|In this lab, you will learn some of the basics of [[6502]] assembly language, in preparation for learning more complex x86_64 and AArch64 assembly language.}}

# 1. Enter the breakout room assigned to you.# 2. Select one person to be the "Driver", who will type/operate the computer for the group. # 3. The driver will open the [[6502 Emulator]] at [http://6502.cdot.systems] (and, ideally, this lab page as well).

54. Test the code by pressing the Assemble button, then the Run button. If the there are any errors assembling (compiling) the code, they will appear in the message area at the bottom of the page. Make sure the code is running correctly and that everyone in your group understands how it works. Try some experiments: use different colours, or draw only every second dot.

6=== Writing Code ===5. Add this instruction after Write code to draw a green line across the <code>loop:</code> label top of the bitmap screen and before a blue line across the <code>sta ($40),y</code> instruction: tyabottom.

76. What visual effect does this cause, Extend the previous code to draw a yellow line down the left side of the screen and how many colours are on a purple line down the screen? Why?right side.

97. In the [[#Resources|Resources]] section, the opcode/instruction references will tell you the number of machine cycles that each instruction will take. If your system is running at 1 MHz (a typical speed for a 6502 processor), each machine cycle will take 1 microsecond (uS). What visual effect does this cause, and how many colours are on is the screen? Whytotal time that your code (from step 6) will take to execute?

11Go back to the bitmap code above, and try these experiments:# Add this instruction after the <code>loop:</code> label and before the <code>sta ($40),y</code> instruction: <code>tya</code># What visual effect does this cause, and how many colours are on the screen? Why?# Add this instruction after the <code>tya</code>: <code>lsa</code># What visual effect does this cause, and how many colours are on the screen? Why?# Repeat the above tests with two, three, four, and five <code>lsr</code> instructions in a row. Describe and explain the effect in each case. # Repeat the tests using <code>asl</code> instructions instead of <code>lsr</code> instructions. Describe and explain the effect in each case. 12. # Remove the <code>tya</code> and all <code>asl</code> and <code>lsr</code> instructions. 13. # The original code includes one <code>iny</code> instruction. Test with one to five consecutive <code>iny</code> instructions. Describe and explain the effect in each case. '''Note:''' ensure that the Speed slider is on its lowest setting (left) for these experiments. === Writing Code, Part 1 ===14. Write code to draw a green line across the top of the bitmap screen and a blue line across the bottom. === Writing Code, Part 2 ===15. Extend the previous code to draw a yellow line down the left side of the screen and a purple line down the right side.

# The results from the ''Bitmap Writing Code'' portion portions of the lab, describing what happened in each case including the code, a description of how the code works, and the reasons for itresults produced.# The results from Your answers to the two ''Writing CodePerformance'' portions of the labquestion, including the code, a description of how you reached your answer.# Optional (Recommended): the code worksresults of the Experiments section (above), and the results producedyour explaination for each observed result.# Your experiences with this lab -- your impressions of the Assembly Language, what you learned, and your reflections of on the process.