Abstract: A task scheduler system including an array of priority queues for use in a real time multitasking operating system including equation lists, configuration lists, a function library, input and output drivers, user-created task definition lists of major and minor tasks and interrupt handlers. The system includes task scheduling apparatus which, upon the completion of each library function, interrogates the priority queues and finds the highest priority task segment whose requested resource is available and executed, and which executes task segments in the same priority queue in round-robin fashion. The system further includes task creation apparatus and apparatus for maintaining the status of all major tasks in a system in the states of unlocked and done, unlocked and active, unlocked and waiting, locked and active, or locked and waiting.