Interface Ports :
There are different interface versions of the same printer models that we sell. If you ordered the wrong interface port for your printer, in most cases this can be resolved by switching out the interface with an existing one at your location, or by shipping you the correct port without having to return or exchange the printer(shipping and difference in price will apply where applicable). Most of the models we sell have interface cards that are easily user interchangeable, but please make sure you are ordering the correct version for your needs before checking out. Contact Us if you have any questions about your order or selecting the proper printer interface version.

Square Hardware FAQ :
Only Star Micronics TSP650, TSP650II, TSP100 and SP700 Printers with ETHERNET or BLUETOOTH Connection are compatible with the Square Up App using a standalone tablet or phone. If you are using the Square Stand Hardware, you can use either the Ethernet, Bluetooth or USB version of these printers.

Identifying Types of Printer Interface Ports :
Epson interface cards used for reference, click on images for a supersized view.

Serial RS-232 Interface Port	Parallel Interface Port
Micros IDN Interface Ports	USB Interface Port
Ethernet Interface Port	Micros Ethernet Interface

Identifying the Interface Ports on the back of your POS Printer :

Epson TM-T88IV Printer with Serial Port Interface

Identifying Interface Ports on your Computer :

**Please note, some new computers may not have a serial or parallel port, only USB.
Please check your system compatibility before ordering**