Serial communications is sufficiently complex that special chips have been designed to do the work of
forming and timing the strings of bits that comprise serial data. Such a chip is called a universal
asynchronous receiver transmitter or UART. Without UARTs, communications programming would
be very complicated. The IBM family of microcomputers use the Intel 8250 UART.
The Intel 8250 is a programmable Universal Asynchronous Receiver/Transmitter packaged in a 40-
pin integrated circuit.