Processor surrogate for use in multiprocessor systems and multiprocessor system using same

A processor surrogate ( 320/520 ) is adapted for use in a processing node (S 1 ) of a multiprocessor data processing system ( 300/500 ) having a plurality of processing nodes (P 0 , S 1 ) coupled together and to a plurality of input/output devices ( 330, 340, 350/530, 540, 550, 560 ) using corresponding communication links. The processor surrogate ( 320/520 ) includes a first port ( 372, 374/620, 622 ) comprising a first set of integrated circuit terminals adapted to be coupled to a first external communication link ( 370/590 ) for coupling (P 0 ) of the plurality of processing nodes ( 310, 320/510, 520 ), a second port ( 382, 384/630, 632 ) comprising a second set of integrated circuit terminals adapted to be coupled to a second external communication link ( 380/592 ) for coupling to one ( 350/550 ) of the plurality of input/output devices ( 330, 340, 350/530, 540, 550, 560 ), and an interconnection circuit ( 390, 392/608, 612, 614 ) coupled between the first port ( 372, 374/620, 622 ) and the second port ( 382, 384/630, 632 ).