The Help file states:
With that in mind, if you cannot get the cards seen by BI5, then the next option could be an NVR with analogue inputs. That can either be used as a standalone device, or again **some** can be used as an interface for Blue Iris. It's up to you.USB, Firewire (IEEE-1394) and Analog cameras (via digitizing device) may be added. In all cases, compatible Windows DirectShow drivers must be available. That is, the camera should be working outside of Blue Iris using general Windows software such as Movie Maker or AmCap. If the device requires proprietary software from the manufacturer for operation, it may not be compatible with Blue Iris. When a compatible device is selected,
you may edit its Advanced properties