In this paper, the authors present an open-source Serial ATA core designed for Virtex-4 FPGAs. This core utilizes the RocketIO Multi-Gigabit Transceiver (MGT) of the Virtex-4 to interface with hard drives at SATA Generation 1 (SATA I, 1.5 Gb/s) and Generation 2 (SATA II, 3.0 Gb/s) speeds. A full design hierarchy from host software to the physical layer is provided with the distribution to facilitate design use. A simple, FIFO interface allows for easy integration with other FPGA modules. The demonstration illustrates the correct write and read behavior of the core using a Xilinx ML405 board and a solid state disk.