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. At speeds higher than 9600 baud, owners discovered that the serial ports of the computers were not able to handle a continuous flow of data without losing characters. Exchange of the 8250 (having only a one-byte received data buffer) with a 16550, and occasionally patching or setting system software to be aware of the FIFO feature of the new chip, improved the reliability and stability of high-speed connections.