Gemalto proposes a dedicated API designed to simplify the development of applications interfacing with serial GemCore-based smart card readers. This API is based on the GBP protocol that is a Gemalto proprietary protocol implemented in the GemCore chipset.
You can download the GBP Library Kit >> here.
The kit includes source code, samples and documentation.
Note that the GBP protocol is not implemented in the GemCore Pro based readers (like PC-Link).