EE 361 LAB 2
                        MC68HC11 Program Debugging

References:    EE361 texts, MC68HC11 Reference Manual

Schedule: Week of: 9/15 Pre-lab due
          Week of: 9/22 Programs demonstrated

1    Pre-Lab:  The pre-lab is to be handed in at the start of
               the lab.  
     Submit a memo report to answer the following questions:
          What do the following monitor commands do?:  MD,
               RM, MM, T, BR.
          What does each of the following monitor routines do and how do you use them?  OUTSTRG0,
               OUTLHLF, and OUTRHLF.

2    Using the Buffalo Monitor, assemble the following program at $c000.  After you have entered it,
     trace through it one step at a time.  Explain to your lab instructor what you see on the screen.  In
     particular, explain what is happening to the condition code register at each step.

          LDX  #C000
          LDAB #2
     LOOP LDAA 0,X
          INX
          DECB
          BNE  LOOP
          SWI

3    Assemble the following program.  The program is to allow you to enter a character from the
     keyboard and to print the hexadecimal code used by the computer to represent that character.  For
     example, if you type A after starting the program the display should show A=41.  It doesn't do it. 
     Why not?  Fix it so it does.  Demonstrate to your lab instructor.  

     Operation Operand   Comment
     JSR       INCHAR    Get a character from terminal
     TAB                 Save it temporarily
     LDAA      #3E       Load ASCII code for =
     JSR       OUTA      Print =
     TBA                 Get the data back
     JSR       OUTLHLF   Print the left half byte
     JSR       OUTRHLF   Print the right half byte
     SWI                 Return to the Buffalo Monitor

4    Using elements of this program and other monitor utility routines, modify the program to print
     A = $41 or B = $42, etc. (including the spaces in the string).  Use the OUTSTRG0 monitor routine
     to do this.

5    Grading:  Pre-Lab 5 points, Program demos (part 3, 5 points; part 4, 5 points).