July 2003
Beginner to intermediate
874 pages
38h 13m
English
Once you have installed and configured the serial port hardware, the next step is to configure the operating system to use it. Windows automatically recognizes proper IRQ and base address values for serial ports reported by the BIOS that use standard BIOS settings—COM1 and COM2 in this example. Depending on the BIOS, nonstandard COM port assignments are often detected, but the hardware settings may not be reported correctly. For example, when we installed COM3 on an older system using 0x3E8 and IRQ 10, Windows 95 detected COM3 on 0x3E8, but assumed that it used IRQ 4.