Modem hangs(just screams) instead of fully connecting.

I am having issues connecting to other QNX 4 machines. I am using an IBM T42 laptop running QNX4 through a microsoft virtual machine. I have tried two different init strings “ATDT” & “at+MS=v90” but neither of them are working. The modem I’m trying to connect to on the other end is a Black US Robotics v.92 modem with pins 3,5,7,& 8 down.
The modem just hangs and gives me a continuous tone that doesn’t change pitches.

I’m looking for someway to troubleshoot this. I can connect to the same machine with a “Best Data v.92 PCM/CIA” modem without issue.