What are serial ports?
Serial ports are a type of computer interface that suits the standard RS-232. These are 9 -pin connectors that pass information, incoming or outgoing, one byte at a time. Each byte is divided into series of eight bits, so the term is a serial port.
These ports are one of the oldest types of interface standards. Before the internal modems became common, external modems were connected to computers through serial ports, also known as communication or ports "com". Computer mice and even keyboards also used them. Some of the 25-pine connectors used, but the 9-round variety was more common. They are controlled by a special UART (Universal Asynchronous receiver).
Serial ports differ from 25-pin parallel ports in that the parallel ports transmit one byte at the same time using eight parallel wires that each bears one bit. In parallel with the data that move in parallel, the transfer rate was greater. Parallel port couldSupporting measures of up to 100 kilobytes of the second, while serial ports supported only 115 kilobites per second (KBPS). Later improved technology moved serial speed to 460 kbps.
In traditional computers, serial ports were configured as follows:
configured for using com 1 and com 3 ports could not be active at the same time because they shared an IRQ 4 interruption. The same was true for COM 2 and Port COM 4.Slexii.
Today, serial ports are used mainly for dialing modem and current operating systems automatically process configuration. Newer and faster USB (Universal Serial BUS) and Firewire technologies have otherwise replaced both serial and parallel ports. USB supports speeds of 1.5 megabites per second up to 60 megabytes per second. Firewire boasts transmission rates between 100 and 400 megabits per second.