Here are the OS/2 WARP settings that work for me and my Cardinal MVP144DSP Modem. I have OS/2 installed on E: drive so you may have to edit these files for your particular system configuration. I am running OS/2 on a 386SX25 with 8 megs RAM and have had no problem with the DSP modem using these settings.
Included are these files:
MODEM.BAT - batch file for loading DATA144C personality into DSP modem. Place this in your Startup folder.
FAX.BAT - Loads Fax personality.
MODEM.SET - Loadable settings for DOS session MODEM.BAT
PROCOMM.SET - Loadable settings file for ProComm Plus for DOS.
WINCIM.SET - Loadable settings file for WinCIM v1.4 (Note: The SESSION_PRIORITY is set so high as to give more accurate download times. You can turn this setting down for background operation.)
I hope these files are of some help. I don't know all the answers but this may get you started in the right direction. Good Luck!