OSLab: Module 1 - Basic Device Drivers

Overview

Module 1 deals with the physical devices required for OSLab: the clock, the keyboard, and the interrupt controller. The target executable module, M1.EXE, exercises both the clock and the keyboard; if a key is pressed within the first 30 seconds of running the program, the program stops and displays the number of 1000s of a second that have elapsed. If a key is not pressed, the program terminates after 30 seconds.

Support Files

The .H (header) files contain data structures required for this module and the devices. The .C files contain the source code for:

• the device drivers (CLK.C, clock and KB.C, keyboard),

• module initialization (MOD1INIT.C),

• the mainline (M1.C), and

• determining the actions to be taken when external input is received (HWDATA.C).

Note that the keyboard software is designed to capture the CTRL-ALT-DEL sequence and return control to DOS. All subsequent modules that use the keyboard software can be terminated using CTRL-ALT-DEL.

Typing CTRL-ALT-DEL inside a Windows 95 DOS window will cause Windows 95 to issue a prompt to the user, asking which process/window is to be terminated.