There are two subsets within each category of graphics driver: old-model drivers and minidrivers. Microsoft supports and strongly encourages the development of minidrivers for graphics devices. A display minidriver is a graphics driver that uses the Microsoft device independent bitmap (DIB) engine to accomplish most or all of actual drawing. For display minidrivers, most of the thirty or so required functions call directly into the DIB engine. For printer minidrivers, even less coding is required. Printer-driver developers use the Microsoft Windows UniTool application to initialize required structures and rely on a second Microsoft-supplied DLL, UNIDRV.DLL, to make calls into the DIB engine.
For specific details about creating a display driver, see Part 5, "Display Drivers"; for specific details about creating a printer driver, see Part 6, "Printer Drivers".