Printer and Peripheral Interface Types

Problem Description

This document will not explain details about the different interfaces. It is meant to help you identify the different interfaces used on your POS Computer and Peripheral Devices. 

Ports on the Printer

Confused about what interface your printer is using? 

Here are the common printer interface connectors As seen from the back or underside of your PRINTER


USB (Type B) interface. This is now the most commonly used printer interface, and is used on a multitude of computer peripherals.
36 pin Centronics interface (Parallel Port). It is the second most used printer interface, but has largely been replaced by USB.
9 Pin (Female) Serial Interface. It is one of oldest interfaces, but is still used on some printers and other peripheral devices such as barcode scanners, pole displays, scales and credit card pin pads.
25 Pin (Female) Serial Interface. It is the oldest of all the  interfaces listed here, but it is also still used on some printers, scales and pole displays.
Cash Drawer Interface Port. Sometimes referred to as the RJ11 or RJ12 port.

Ports on the Computer

Confused about what the Corresponding interface on your computer looks like? 

Here are the common interface connectors As seen from the back of your COMPUTER


USB (Type A) This is now the most commonly used printer interface, and is used to connect a multitude of computer peripherals to your PC. Most PCs today have between 2 and 8 of these connectors.
25 pin (Female) Parallel port connector used to connect your printer's Centronics port back to the computer.
9 Pin (Male) Serial connector. This port may not exist on most modern computers, but is still well used on many computers that are specially purposed as POS Terminals.

Other Special Purpose Ports

While these ports are not used for interfacing printers or Point of Sale specific devices, it may be helpful for you to identify these ports. 


15 pin VGA/SVGA Video output port (connects to the monitor).
Keyboard/PS2 Mini Din connector.
Mouse Mini Din connector.
HDMI port. This is an audio/video interface often used to connect to a computer monitor or digital television.



Other USB types. These are most commonly used on Laptops, Tablets and Smart Phones. 


Mini USB port.Mini USB cable.
Micro USB port.Micro USB cable.

Created by Steve Wind April 29 2016 

Updated July 22 2019