Abstract: In a multi-tasking system a writer task generates real-time and non real-time messages having multiple priority levels in an ascending order arranged in a plurality of priority bands. The real-time messages have predetermined timing deadlines. A plurality of queues indexing the messages by pointers, there is one queue for each priority band. A dispatcher moves pointers from a lower priority queue to a higher priority queue in response to a time-out signal dependent on the timing deadline. A data push agent transmits the messages indexed by the pointers according to the multiple priority levels.