A value which enables special heuristic functions. The value is a sum. This sum initially takes the value zero, Then, for each heuristic function, H, in the range 1 through 32, that is enabled, 2 raised to (H - 1) is added to the sum. The heuristic functions are: H Heuristic Function 1 system reset when an invalid buffer is detected 2 system reset when free and transmit lists are mixed 3 system reset when the buffer counter overflows 4 system reset when the frame status overflows 5 system reset when queue head passes tail 6 system reset when the self-monitor loopback fails 7 system reset when the port status interface hangs 8 system reset when the LED interface hangs 9 system reset when the buffer interface hangs 10 system reset when the frame DRAM interface hangs 11 system reset when invalid hardware activities are detected 12 reserved (must be zero) 13 reserved (must be zero) 14 reserved (must be zero) 15 reserved (must be zero) 16 reserved (must be zero) 17 reserved (must be zero) 18 reserved (must be zero) 19 size of transmit queue is 1.5K. 20 reserved (must be zero) 21 reserved (must be zero) 22 reserved (must be zero) 23 unfreeze LEDs upon a POST failure 24 reserved (must be zero) 25 reserved (must be zero) 26 reserved (must be zero) 27 reserved (must be zero) 28 reserved (must be zero) 29 reserved (must be zero) 30 reserved (must be zero) 31 reserved (must be zero) 32 reserved (must be zero)