Credit Card Reader
From MerchantOS Manual
The magnetic card reader needs no software installation or reconfiguration. MerchantOS software is designed to work with the factory default settings of the recommended card reader (Magtek 21040108). Just Plug the Reader into an available USB port.
[edit] Mac Users
Do not go through the keyboard identification process when plugging in your credit card reader. Cancel the process if you are prompted to identify a keyboard after plugging in the credit card reader.
