What is a Null-modem Serial Cable

Typically with serial ports, you connect a computer to something like a modem. This is how serial ports are designed: you connect a computer, or Data Terminal Equipment (DTE), to a modem, or Data Communication Equipment (DCE). When you connect a computer to another computer, or DTE to DTE, you need a special cable called a null-modem cable. WDEB386 requires only the most basic null-modem cable, the three-line null-modem cable. The following illustration shows the null-modem cable's connectors. (The pin numbering would be backwards if you were looking at the computer's ports.)

The following table shows the pin numbers and names of the cable's three lines.