128k Modem Single Channel Configuration


I got a conceptronic 128k isdn modem which I can use with windows laptop and G4 imac os panther. (even though the shop guys here in Ireland were telling me I couldn't get an external isdn modem to run on both platforms!)

The windows laptop 95%of the time will only grab one channel and drops the other one while connecting.

The imac on the other hand ALWAYS grabs the 2 channels...which I don't want. I can set it to drop one channel when a phonecall comes in, but I can't seem to do this BEFORE hand.

There must be something in the depths of the computer that I don't know about....?

I'd like to use one channel for the phone and one channel for the internet.

The isdn box has my isdn modem plugged into the digital bit, and I have 2 normal phones plugged into the slot for the normal phones. There is one digital slot free.

The conceptronic modem..is a Tiny usb modem...so hopefully the answer to this is generic rather than specific software.

thanks guys, hope this is not too garbled.
I'm in Ireland by the way.
Moved from Design & Media to Networking & Compability.