Installing a new gateway requires that you have the source code to Pinnacle Cart.
Here are the steps to add a new gateway to our system.
1) Your gateway should have the same object-oriented interface as of the other Pinnacle Cart payment classes. It has to inherit the base class PAYMENT_PROCESSOR (extends PAYMENT_PROCESSOR). For an example, take a look at payment_authorizenet.php. The easiest way to to this is to use one of existing gateway classes as a base. Choose the most similar to the one you are installing and modify it.
2) Next, add your gateway to the database in the payment_methods table
3) Keep the settings for your gateway in "settings" table.
4) Pinnacle Cart will automatically creates instance of gateway class and calls class methods when it is required
5) One of the most important methods is process(). All gateways contain validation code
