Note: part 2 (bash scripting) of the original version of the lab is cancelled following our snow closures/revised schedules.

Schedule:

In the lab of week 7 (Feb. 20) we'll introduce Marie for assembly language programming.

The lab exercise is due at 5pm on Tuesday March 5th (after the study break).

Reference material:

• Marie web interface (github)
  resources from HWMath.com

Sample code:

Open Marie (either under Applications->Other->MARIESimulator in our lab, or using the github web interface) and try entering the following in the "Assembly Code" section

/ program to count down from user value to 1 input / get the starting value Top, skipcond 800 / we're not done while it's > 0 jump Done / if we reach this we're done, go to the end output / print the current value subt decr / subtract 1 from the current value jump Top / go back to the top of the loop Done, halt / end the program decr, dec 1 / variable named decr, initialized to decimal value of 1

• Click "Assemble", and fix any errors.
• Click "Run", enter the value 3 when prompted.
• In the output section you should see it count down from 3 to 1.
• Click "Restart", then use the "Step" button to go through the program again, one instruction at a time, watching the value in the Acc(umulator) and the output as you do so.
• You can also see the contents of the other registers (PC, IR, MAR, MBR, Input, Output) and the contents of memory (at the bottom of the window).

The Marie assembly language code above is roughly the equivalent of

   int acc = 0;
   int decr = 1;
   scanf("%d", &acc);
   while (acc > 0) {
      printf("%d\n", acc);
      acc = acc - decr;
   }

Lab exercises:

Obtain the lab 3 repository using the same techniques as previous labs, i.e.

cd csci162
ssh csci fork csci162/lab3 csci162/$USER/lab3
git clone csci:csci162/$USER/lab3
cd lab3

Lab exercises:

Once you have completed all parts of the lab, be sure to add, commit, and push your updates:

git add   .  
git commit -m "finish lab3"
git push

REMEMBER: if you miss the add, the commit, or the push then your changes never make it back to the central repository, so they'll never get marked!