I notice that you talk about CMR. Maybe you typo'd CNR? If so, I didn't know that it was just attached to the PCI bus. What possible reason is there in having a different connector?)

The first version of the CNR slot was actually called AMR (Audio/Modem Riser). Maybe that's where the typo originated ? Anyway, here's a little info on the subject. AMR/CNR cards relie heavily on the CPU and do little more than provide the connector for the output. That, in combination with the fact that an AMR/CNR card costs practically the same as a real, self-sufficiant modem/audio/NIC card has prevented this technology from becoming a success.