Serial Cables
The serial port is a legacy connection interface where data is transmitted over one wire one bit at a time.
- Start, stop, and parity bits are used to format and verify data transmission
- also referred to as Recommended Standard #232 (RS-232)
- While modern interfaces like USB are also serial, an RS-232 interface uses much less sophisticated signaling methods
- supports data rates up to about 115 Kbps only
- Serial ports are generally associated with connecting external modems, used to establish dial-up Internet connections
- this function has largely been superseded by USB
- may also come across serial ports on network equipment, where a serial connection can be used to manage the device
- RS-232 specifies a 25-pin hardware interface
- in practice, PC manufacturers used the cheaper 9-pin D-subminiature (DB-9) female port
- In Windows, the serial port is referred to as a Communications (COM) port
Info
You might also come across PS/2 serial ports. PS/2 is used to attach mice and keyboards. PS/2 ports use a 6-pin mini-DIN format. The green color-coded port is used to attach a mouse, and the purple one is for a keyboard.
