Real time system applications are increasing every day. Real-time systems span from microcontrollers in automobile engines to very complex applications, such as aircraft flight control or process control in manufacturing plants. Failure in meeting the tasks'' deadlines can lead to catastrophic consequences. Recently, there has been an interest in techniques for developing real-time applications on general- purpose operating systems (GPOSs), like UNIX, MINIX, LINUX etc. With this in view, this work aims at adding real time extensions to the MINIX (Mini-UNIX) system. This work required a detailed study of the MINIX source code - process management, clock, inter- process communication, and interaction between the various modules during system calls. Along with an overview of our work, this book also outlines the file system backup tool and versioning tool that we had to develop in order to mitigate the problems of frequent system crashes as are inherent in any work involving kernel debugging.