Since PC/104-"Plus" is based on PCI, there is no need to set a Base Address, IRQ, or DMA channel on the peripheral boards. However, it is necessary to specify the PCI Slot Number of a peripheral board when it is installed. This is commonly set by a rotary switch, DIP switch, or jumpers on the peripheral board. Each PCI peripheral board in the system must have the PCI Slot Number set to a unique value. Failure to do so may cause erratic system behavior. The peripheral closest to the CPU should be set for the first slot, the next board should be set for the second slot, etc.