PC Serial Ports
E-4
Issue 1 January 1997
more than one COM port (that is, the COM1 and COM3 ports were both assigned to
IRQ4, and the COM2 and COM4 ports were both assigned to IRQ3). Then, under the
assumption that at most two serial ports would be active simultaneously (for example,
COM1 and COM2, which have unique IRQs), conflicts would not occur.