We are upgrading a comm. module from VB3 with MSCOMM.vbx to VB6 with MSCOMM32.OCX v6.00.8169 DTD 6/24/98. With the new control found pattern that Dell pc's with internal USR 56k modems from Dell will not respond most of the time (i.e USR Model 0484 & 0584).
If switch back to old 16-bit comm module same modem works fine. Happens on all operating systems. On same Dell pc external USR works fine. Also tested switching to internal USR Winmodem as well as a USR 56k PCI modem off the shelf (not from Dell) and worked fine on same pc.
In the old VB3 version of the software had same problem and was solved by upgrading to newer version of MSCOMM.vbx (v126.96.36.199 DTD 5/12/93). In this case cannot find newer version of MSCOMM32.OCX.
Dell tech support heard of this problem and said try USR for a different driver. Since the Dell with internal modem is so common I'm looking for a way to make the app work without having to ask everyone to change drivers and/or modems. Thanks!