Universal Serial Bus (USB) port technology has emerged in response to the proliferation of external peripheral devices (scanners, digital cameras, removable drives, etc.), that are increasingly being connected to the latest generation of PCs. USB behaves in a similar fashion to conventional bus ports (i.e., serial, parallel, PS/2), but since it does not require any IRQs, more devices can be attached to the system, and the problem of an IRQ conflict is eliminated.