CS609 Assignment 2 Solution Spring 2018

Semester: Spring 2018

CS609: System Programming

Total Marks: 20

Due Date:

May 29, 2018


Please read the following instructions carefully before submitting assignment. It should be clear that your assignment will not get any credit if:

§  The assignment is submitted after due date.

§  The submitted assignment does not open or file is corrupt.

§  You have not followed steps described in Detailed Instructions of the problem statement.

§  Assignment is copied(partial or full) from any source (websites, forums, students, etc.) Strict action will be taken in this regard.

Note:You have to upload only .doc or .docx file. Assignment in any other format (extension) will not be accepted and will be awarded with zero marks.


The objective of this assignment is to provide hands-on experience ofSystem Programming concepts including:

·         Interval Timer

·         Accessing PC Speaker

·         Loading divisor values in Interval Timer

For any assignment related query, contact at CS609@vu.edu.pk

Problem Statement:

Write a C program that will turn on PC speaker (for variable-pitched sound) by using port 61H of Interval Timer. The divisor value for Interval Timer will be last eight digits of your Student ID.

Detailed Instructions:

1)      In this program,you will access internal PC speaker by using port 61H. Least two significant bits of port 61H are used for connecting PC speaker to Interval Timer.

2)      In order to program Interval Timer, you have to first load the Command Byte into the Command Register. Calculate Command Byte according to following criteria:

a.       Channel: 2

b.      Interval Timer Mode: 2

c.       Counter: Binary

d.      Divisor bytes to be loaded: All (For calculating divisor value, read instruction 4)

3)      You will first load last four digits of your Student ID as a divisor value (see the purple color digits in below example ID), and then after a delay of 2 seconds, you will again load new divisor value which will be next four digits of your Student ID (see the orange color digits in below example ID).


4)      For producing delay, use Timer Count, a double word variable in the BIOS data area which is placed at the location 0040:006C

5)      After loading each divisor value, turn on the PC speaker

6)      You can check the output of the program by booting your system in DOS mode and then running the exe file. But does not worry if PC speaker does not produce sound; the host operating system may restrict you to directly access PC speaker. Just focus on the concepts.

7)      Your assignment file should be a single Word file (.doc or .docx) containing complete code.

8)      You can use Consolas font for enhancing readability of the code in Word file.