The CP611, called an "assignment" processor board, becomes part of a multiprocessing system for the CompactPCI bus when configured with a system controller processor board such as the firm's CP610. As many as seven CP611 boards can be configured in a standard CompactPCI backplane to offload the system controller of relatively independent processing tasks.The CP611 uses DEC's 21554 Drawbridge IC, which implements a non-transparent PCI/PCI bridge. This enables the CP611 to act as a slave to the system controller and to appear as a single virtual device. The system controller is prevented from finding and allocating the "hidden" resources of the CP611. Each CP611 board retains its autonomy to perform its assigned duties. The board accommodates most Socket 7 CPUs, including low-power versions and those with clock rates of 300 MHz or more. Full peripheral support is included on-board.