In this paper, the authors describe a real-time USB 2 subsystem for the quest operating system. Quest is designed for real-time embedded systems. Such systems need to interact with their environment using sensors and actuators. On many embedded platforms today there is support for basic serial, USB 2.0 and 100 Mbps Ethernet. Of these, USB 2.0 supports the highest throughput, while also supporting real-time communication. They show how the quest USB 2.0 sub-system improves upon some of the deficiencies in USB software stacks in systems such as Linux through experimental evaluation.