The QBUS is wired from slot 1 to slot 2 to slot 3 on the A-B connectors, with CD interconnect between slot 1 to slot 2 to slot 3 on the C-D connectors. Starting in slot 4 continuing to slot 8 the QBUS is wired in a serpentine pattern with QBUS on both the A-B and C-D connectors.