Assignment 10, due Apr 19

On every assignment, write your name legibly as it appears on your University ID card! Homework is due on paper at the start of class on the day indicated (usually Friday). Exceptions will be made only by advance arrangement (excepting "acts of God"). Late work must be turned in to the TA's mailbox (ask the CS receptionist in 14 MLH for help). Never push homework under someone's door!

1. Background: Look at the specifications for the Hawk video display interface in chapter 12 of the notes.

   A Problem: Write a Hawk subroutine that accepts the following parameters:

   • R3 holds a character to plot on the screen
   • R4 holds the x coordinate where that character should be plotted
   • R5 holds the y coordinate where that character should be plotted

   Do this without calling PUTAT or PUTCHAR or other Hawk output routines. You are free to call multiplication or division routines in the hawk monitor, if you need them. Your goal is to go straight to the Hawk's I/O hardware, bypassing the Hawk monitor for I/O. (2 points)

   Note: This is not a machine problem, but you are welcome to test your work. We will only grade your code, we will not try to run it. We will be mercyless in grading unreadable or illegible code.

2. Background: Consider this code fragment written in something like python and Java:

   try {
      if (b == 0) throw;
      a = b;
   } catch {
      a = -a;
   }
   

   A Problem: Write equivalent SMAL Hawk code. (1 point)