How to determine what UART is in your Internal hardware modem

Software requirements: DOS 5.0 or higher or Windows 3.1

Hardware requirements: IBM compatible computer

There is a program that can be found in both your Windows and DOS directories (MSD.EXE). This MicroSoft Diagnostic program can be used to determine what Serial Ports are on the system, including the presence of a 16C450 or 16C550 UART.

Follow the instructions following to determine what UART is used for all Serial Ports on your system (Including your External Serial Ports on your I/O card):

1. From the DOS prompt type CD\DOS or change to the directory where DOS 5.0 (or higher) or Windows 3.1 is located.
2. Type MSD and press ENTER.
3. After the MSD finishes examining the system and the opening screen appears, press C   for Com Ports.
4. A screen will appear listing the Com Ports found on the system.

This screen lists the addresses of the Com Ports found on the system including other information about the Com Ports found. The bottom of each column has a field labeled UART Chip Used. This is where the information you are looking for is located.