1,885
edits
Changes
→Lab 1
=== Writing Code, Part 2 ===
6. Extend the previous code to draw a yellow line down the left side of the screen and a purple line down the right side.
=== Optional: Experiments ===
# Add this instruction after the <code>loop:</code> label and before the <code>sta ($40),y</code> instruction:
tya
# What visual effect does this cause, and how many colours are on the screen? Why?
# Add this instruction after the <code>tya</code>:
lsr
# 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.
# Remove the <code>tya</code> and all <code>asl</code> and <code>lsr</code> instructions.
# 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.
== Write-Up ==