COSC 065 Hardware Systems

Fall 2008

Homework Assignment #10

Basic x86 Assembly Language

Due: Tuesday, Nov 25, 11:59PM CST

Submit: Turn in your source files using the turnin command on Morbius. Please name your files "q1-stats.S", "q2-exp.S", and "q3-ctof.S". Failure to follow this simple convention may significantly delay grading of your assignment.

Work may be completed in teams of two. The names of both partners must appear in a comment block at the top of your file for credit to be given.


Take time to familiarize yourself with the UNIX environment, using the tutorial here.

Intel x86 assignments are to be compiled and run natively on our Linux workstations in the systems lab. You will not require the MIPS Playground or the mipcon tool for this assignment. Instead, compose your program in an empty file, perhaps starting with the Intel x86 demo as a template.

Your work must be compiled on a machine with the proper tools, such as the dual-head Linux boxen in the Systems Lab (CU 310). Consult the professor for advice on connecting remotely if the lab is full or you must work from elsewhere. Intel x86 machines can be identified by running the command uname -p; look for machines that identify themselves as i586, i686 or x86_64. Your x86 programms will not compile or run on the PowerPC and MIPS hardware we have in the lab. You may also consult the Systems Lab machine list to check current architectures available. All of these machines are remotely accessible by secure shell. (E.g. ssh, etc.)

In order to assemble your program, use the command "gcc -m32", followed by the name of your assembly file. In order to run your program, use the command "./a.out". If you do not want your compiled program to be called "./a.out", you may use the "-o" option to gcc to alter the outputed program. Runaway programs can often be killed using Control-C.

Few rules govern the format of assembly language programs. Make an effort to keep your programs readable and well-documented; sometimes the professor gives partial credit if he can tell what you were trying to do, even if it doesn't quite make it.

Q1 - Stats

Write an assembler program that reads in integers from the user until a zero is entered. Print the total, the average (total divided by number of items, truncated to an integer), the highest integer seen, and the lowest integer seen.

? 3
? 4
? 5
? 0

You may assume that overflow and underflow do NOT occur.

Q2 - Exponent

Write an assembler program that reads two positive integers, x and y, and prints x to the y power. Your program should continue asking for integers until it has gotten two positive numbers.

? 2
? 30

You may assume that overflow and underflow do NOT occur.

Q3 - Celsius to Fahrenheit

Write an assembler program that reads a positive integer, and converts that integers from a temperature on the Celsius scale to a temperature on the Fahrenheit scale. You need only use integer precision for the conversion.

? 100

You may assume that overflow and underflow do NOT occur.

[Revised 2008 Nov 19 13:22 DWB]