The Programmer's Reference Manuals (PRM) describe the architectural behavior and programming environment of the chipset and graphics devices. The Graphics Controller (GC) contains an extensive set of registers and instructions for configuration, 2D, 3D, and video systems. The PRM describes the register, instruction, and memory interfaces and the device behaviors, as controlled and observed through those interfaces. The PRM also describes the registers and instructions and provides detailed bit/field descriptions. This information is critical to the development and maintenance of graphics drivers from Intel for this hardware.