part, are made by other manufacturers. A UART function that is register-compatible with the 16550 is usually a feature of multifunction I/O cards for IBM PC-compatible computers and may be integrated on the motherboard of other compatible computers.

Replacement of the factory-installed 8250 UART was a common upgrade for owners of IBM PC, XT, and compatible computers when high-speed modems became available. Above 9600 baud, owners discovered that the serial ports of the computers were not able to handle