Programming Assignments

• As stated in the syllabus, programming assignments constitute 10% of your final grade.
• Each assignment has a window of opportunity during which you can get credit for a correct solution.
• Standard practice will be for these windows to close one second before midnight on the given day.

• The web site for processing these assignments is now up.
• You have been assigned a user name and a password for this site. The user name is derived from your campus email address.
• For example, if your address is "youngwildandwasted@g.cof.edu", then your user name is "youngwildandwasted".
• Your password is your 8-digit campus-wide ID number. You should immediately change this to something more secure.
• Here is the address of the web site. You can copy it and paste it into your browser.

• The first page you see after logging in has a choice button that lets you choose from among the available assignments.
• Once you choose an assignment, you get a page with a text area and a "submit" button.
• Paste your code into the text area and push the button.
• The web site will assemble and run your code and test the results that it gets.
• During the assignment's window of opportunity, the site will record success or failure for each attempt that you make.
• For purposes of your grade, the only thing that matters is whether or not your number of successes is 0.
• I.e. 10 failures and 1 success is the same as 14 successes and no failures.

• Because of the campus firewall, you have to be on campus to get to the grading site.
• You can get to this page from anywhere, so we will keep a list of all the available programming assignments here.
• This page will tell you when any particular assignment is due and what it requires your solution to do.

Here is your workflow for programming assignments.

1. come here to this page and find out what your program needs to do
2. write and debug a solution in MARS
3. next time you are on campus, go to the grading site, copy your code from MARS, paste it into the grading window, and push the "submit" button
4. if you have properly debugged your program, that's it; log out and do something else

Here are some suggestions for doing the programs that involve subroutines.

• In some cases the grader supplies part of the program, and you supply the rest.
• Nevertheless, you need to write all of it in order to test it in MARS.
• The grader replaces your variables in the data segment with its own, so the relevant part of the text segment is all that you need to submit.
• Once you have a working program, you can copy the part that you need to submit for grading and paste just that much into the grading window on the web site.
• Always include this line: ".globl main" in your program. A good place for it is right before the label "main:". That is the correct spelling -- ".globl".
• Any subroutine that you submit will begin with a label; that label should also be declared global in the same way.
• Your main program should always end with these two lines: "li $v0 10; syscall".
• You don't have to, but I find it convenient to put the part that you need to submit at the beginning of the text segment.
• There's a prototype of your complete file for program 7 below. You can copy it from here, paste it into the edit window in MARS, and replace the parenthesized parts with your code.
• Once you have it working, submit the indicated part.
• You can use the same prototype for program 8, but in that case, you should submit the code below the second long comment line.

.data
(your variables here)

################# for program 7 submit the part between this line and the next comment line ################
.text
.globl main
main:
       (your main program code here)
       li  $v0  10    # exit program
       syscall
############################## for program 8 submit the part below this line #####################

.globl inc3
inc3:
       (your code for inc3 here)
       jr  $ra

Here is the list of the programming assignments that are on the grading site.

1. Load the value 1 into register $t0 and the value 2 into register $t1.
2. Add the value in memory location x to the value in memory location y and put the answer into memory location z.
3. Write a program that implements this python statement: z = a + b + c - d
4. Due 18 March -- Write this in assembly language:

   if (x == y) {
       z = 14;
       w = 23;
   }
   u = x + 5;
           

5. Due 20 March -- Write this in assembly language:

   if x == y:
       z = 21
       w = 15
   else:
       u = 17
   x = 29
           

6. Due 20 March -- Write this in assembly language:

   if x == y:
       z = 21
       w = 15
   else:
       z = 15
       w = 21
   x = y = 76
           

7. Due 23 March -- We have a function already written:

   public int inc3(int i)
   
   that adds 3 to its parameter and returns the result.
   
   Write this main program that calls it:
   
   int x = inc3(x);
           

8. Due 27 March: Write a function inc5 that adds 5 to its parameter. I will call it.
9. Due 1 April: Take the strcount1 program on OAKS and turn it into a function
   • the function's name is strcnt
   • it takes one parameter: the address of the string that it is to count
   • it returns the number of characters in the string
   • obviously you'll have to write a main program to call strcnt for testing
   • submit the function for grading, not the main program
10. Due 4 April: Write a function that copies a string.
    • the function's name is strcpy
    • it takes two parameters: the address of the string that it is to count and the address of the location in memory that is to receive the copy
    • there is no returned value
    • there's a .space assembler directive that reserves memory bytes
    • submit the function for grading, not the main program that calls it
    • the test strings won't be insanely long; no more than 80 characters
11. Due 7 April: Write a program that makes y the same as x but with bit4 and bit10 set.
12. Due 9 April: Write a program that makes y the same as x but with bit2 and bit14 cleared.
13. Due 19 April: Write a function named clrfun that clears bit5, bit6, and bit11 in its parameter and returns the result.
14. Due 19 April: Write a function named setfun that sets bit3, bit9, and bit14 in its parameter and returns the result.