System and method for synchronizing operations among a plurality of independently clocked digital data processing devices

TLDR: In this paper, a system for maintaining synchrony of operations among a plurality of devices having independent clocking arrangements is described, where each task is associated with a time stamp that indicates a time, relative to a clock maintained by the task distribution device, at which group members are to execute the task.

Abstract: A system is described for maintaining synchrony of operations among a plurality of devices having independent clocking arrangements. A task distribution device is to distribute tasks to a synchrony group comprising a plurality of devices to perform tasks distributed by the task distribution device in synchrony. The task distribution device distributes each task to synchrony group members over a network. Each task is associated with a time stamp that indicates a time, relative to a clock maintained by the task distribution device, at which synchrony group members are to execute the task. Each synchrony group member periodically obtains from the task distribution device an indication of current time indicated by its clock, determines a time differential between the task distribution device's clock and its respective clock and determines therefrom a time at which, according to its respective clock, the time stamp indicates that it is to execute the task.