Printer driver data files provide information to the printer graphics and printer interface components that indicate the printer’s capabilities. These capabilities include the printer’s memory configuration, the number and type of cartridges, and the number and size of the paper trays. Driver data files can be either minidriver, PPD, or PCD files, depending on the printer type.
A printer minidriver is the GPC data file that RasDD uses to print to a raster printing device. It contains a collection of data structures referred to as the printer’s data table. A data table contains data such as the printer’s resolution, color capabilities, metrics for device fonts, and the strings that correspond to various printer commands. It also specifies printer model-specific aspects of how primitive bitmap and text operations are to be performed.
To create a printer description file for a new printer, use the Unitool program, supplied with the Windows NT DDK. Unitool automatically combines the printer description file with a layer of RasDD interface code to create a printer driver DLL, called a minidriver. For more information about using Unitool, refer to Printer Minidrivers and RasDD or the Unitool online Help.
The PostScript driver uses .PPD files. Each PPD file contains PostScript keywords that provide resource data for a PostScript printing device. For example, the PPD file contains the printer model name, nickname, default resolution, page size, printable area of the page, and a list of device fonts. Unlike the minidriver’s GPC file, which is converted to a DLL when defined, a PPD file is an ASCII text file that must be read by the PostScript driver as part of the device initialization during DrvEnablePDEV.
The PostScript driver can support any PostScript printer as long as it has access to a PPD file for that printer. There must be a PPD file for each PostScript printer supported.
The Windows NT PostScript driver supports Adobe version 4.0-compatible .PPD files.
The plotter driver uses .PCD data files. A PCD data file is generated from an ASCII text file that contains the capabilities of a plotter device. The Windows NT DDK supplies two sample text files; it is recommended that you copy and edit one of these files to define your device. The DDK also supplies the plotgpc program to convert the text file into a .PCD file.