Parallel Port Data is exchanged parallel to this port. This interface is used for fast data exchange. It is usually called parallel port as 1 bit or 8 bytes of data is exchanged through 6 lines. Printers , scanners , CD or DVD drives , zip drives , etc. are connected to this port. This is why this port is also called printer port. Its logical name is LPT (Line print terminal) . Three types of LPT are used for MS -DOS . For example : LPT LPT2 LPT3 has three separate registers on such ports. Namely: 1. Data Register ( Data Register) 2. Status Register 3. Control Register