The purpose of this assignment is to become comfortable writing simple assembly language programs. For this assignment you will write two programs:

• A program to read two integers as input, print their sum as output, and exit.

• A program that reads up to 100 positive numbers into an array and then prints them out (one number per line) in the reverse order in which they were entered. When reading the numbers, a -1 will indicate that there are no more numbers to be read. After the numbers have been printed, your program should exit.

The assembly language we will use is the SPIM system. SPIM is a simulator that lets you write assembly language programs and provides an environment to help you debug them. The SPIM simulator runs on the Shakespeare cluster (hamlet.umd.edu, macbeth.umd.edu, yorick.umd.edu). You have an account on the cluster. When you first use your account, don't forget to change your password. Your user name and password are shown on the paper version of the handout. Presshere to login to your account (you must have the telnet supporting application configured for this to work).

To run the SPIM simulator, you will need to run the command ~hollings/Spim/spim. This will bring up a command interpreter that permits you to load an run the assembly language programs. There are also X and Windows based versions of the simulator. XSPIM is located in ~hollings/Spim/xspim. Press here to download the Windows version. If you use the Windows version, you will still need to transfer your program to your UNIX account to submit it. The official supported version of SPIM for this class is the UNIX version, you are welcome to use the Windows version, but we can't help you with configuration problems.

Once you have completed your two programs, you will use the submit program to turn them in electronically. To run the submit program, type:

~jh01/BIN/submit <program #> <file>

Replace <program #>, by the number of the programming assignment. Part 1 is program number 1, and part two is program 2. <file> is the name of the file that contains your program. When you submit your programs, it is important to remember that:

• each program should be in a separate file.
• each program must contain a comment line indicating your name.
• assembly programs must be well commented. To receive full credit for the programs, they must contain comments.

Late Policy: No late assignments will be accepted.