Using MicroSoft Diagnostics

• Enter MSD by typing the letters "msd" (no quotes), at a DOS Prompt. (NOT in a Windows DOS Box).
  • MSD will report several computer configuration items. We are interested in the COM Ports in this case.

  • Type the letter "C" (or click the button for "COM Ports" if a dos mouse driver is loaded).

  • The port assignments will be listed. The port with the "Clear to Send" marked "Yes" is most likely the modem port.
    (The modem must be switched on and connected to the port).

  • Note the UART chip used on this port. An 8250 or 16540 UART chip will NOT support high speed communications through the port.

  • If MSD does not report a 16550 UART chip on the modem port, the UltraNet Account Configuration Utility can be used to reset the port speed to 19,200 kbps. (Even this has been unsuccessful in some cases with 28.800 kbps modems).

  • A com board having high speed UARTS should be installed, and the existing ports disabled.

• While in MSD, verify that the port address is correct for the number of the port you are utilizing.
  
  • ie: COM 1 = 03F8, COM 2 = 02F8, COM 3 = 03E8, COM 4 = 02E8.
    

  • Check the port addresses to see if they have shifted, (offset), which will prevent proper communications between the computer and the modem .
    This is a most likely result when there is a modem configured for COM 4 and nothing located at COM 3.

  • AMI BIOS are noted for this phenomenon called "address packing".
    MSD will show 02E8 as the address of COM 3.

  • In addition, many video cards occupy address space at 02E8 (COM 4), and will prevent its use for modem communications.

  • Many non-interrupt driven communications programs such as those used by AOL an CompuServe will run under these circumstances, TCP/IP communications programs required for Internet access will NOT.

• TRY TO AVOID INSTALLING AN INTERNAL MODEM ON COM 4.
  • Re-configure the modem switches (or jumpers) to COM 3 at IRQ 5. Sound or network cards may already be set to IRQ 5 and must be moved up to other (free) IRQ's.
    Windows 95 may be able to resolve these conflicts by using the Device Manager if the modem and other devices are of the "Plug and Play" variety.

  • MSD shows free IRQ's as "reserved" under IRQ Status.
    Note that IRQ 5 is usually assigned to a non-existant port, (LPT2), and can be used for other devices.

  • Go the Windows Control Panel, open the "Ports" section, verify the address assignment, and the IRQ setting. Non standard port addresses and IRQ's must be registered here for Windows to be able to communicate with the device on the port in question. (The "Port Speed" setting here has no effect on modem communications).

• Conflicts will result if ports and/or interupts are shared.
  • The computer may "lock up" if there is a port or interupt assigned to more than one device.

  • Your modem will not function properly for TCP/IP (Internet Access), if it is in conflict with a sound board, CD Rom drive or other device sharing its port or IRQ assignment.

  • Have your computer shop determine if all accessories are installed on individual ports and assigned separate IRQ's

Go to Account Configuration.

Go to Trumpet Winsock.

Go to Modems.

Go to Index.