A real time multitasking kernel for the IBM personal computer

Abstract

The purpose of this study is to design a simple, efficient, single-user multitasking kernel for real-time applications on the IBM Personal Computer. Since real-time application consists of many tasks and their order of execution cannot be predetermined, it is almost impossible to write a monolithic block of code that can meet the response time of all the tasks. By using multitasking, each task is assigned a priority based on the urgency of its response time. The kernel uses a priority-based preemptive scheduling strategy to select a new task to run, so the highest-priority task can always get to run when it is ready. The Basic Input/Output System of the PC is rewritten to be reentrant so that it can be shared by multiple tasks.