Unidrv

UniDrv (Universal Printer Driver or Unidriver) is a GDI-based Microsoft Windows universal printer driver and architecture for non-PostScript printers. It is used to simplify driver development of non-PostScript printers (also called Winprinters) for printer manufacturers. "Unidrv" allows the creation of a printer-specific minidriver in the form of a GPD (Generic Printer Description) file, similar to a PPD file, which is much simpler than kernel mode driver development. Starting with Windows Vista, Unidrv is intended to be succeeded by XPSDrv. The XPSDrv printer driver extends Microsoft's GDI-based, printer driver architecture to support consuming XML Paper Specification (XPS) documents and is more modular and extensible. With an XPSDrv printer driver, the XPS Document format is used as a spool file format and as a document file format.

Driver file details

The Unidriver is implemented as a set of DLL and GPD files along with other printer-specific support files:

* "UniDrv.dll" is the printer graphics driver file for printer languages based on raster images, including most inkjet and dot-matrix printer languages.
* "UniDrvUI.dll" is the configuration file. It displays the user interface for "UniDrv.dll".
* "UniRes.dll", "StdNames.gpd", "TtfSub.gpd" and some other support files.
* "Raster minidriver", which has the file name extension ".GPD", is the data file, and is also called the characterization file. The file name depends on the printer or printer family.

Newer "Unidrv"-based printer drivers from some printer vendors, e.g. Hewlett Packard, may contain many other support files to allow support for more printer-specific options.

Unidrv capabilities

The "Unidriver" is also called the raster driver because it supports raster (bitmap) graphics printing and is compatible with many printers. This driver supports the following features:
* Color printing at various depths, such as 4 bits per pixel (bpp), 8 bpp, and 24 bpp.
* Scalable TrueType and OpenType fonts, device fonts (including double-byte), grayscale printing, font substitution, run length encoding (RLE), Tag Image File Format (TIFF) version 4.0, and Delta Row Compression (DRC).
* An extension interface that allows printer manufacturers to extend and customize the driver for specific models.
* Vector graphics languages HP-GL/2 and PCL-XL, monochrome, and color. This is a change from the version of Unidriver that shipped with Windows 2000. (The added HP-GL/2 support, which is used with normal PCL5e printers, is different from the HP-GL/2 for plotters, which is used only for plotters.)

Determining if the printer driver is Unidrv-based

To determine whether a driver is "Unidrv"-based, the following steps need to be taken on Windows:

# Click the "Start button", and then open the "Printers" folder.
# From the "File" menu, click "Server Properties".
# Click the "Drivers" tab.
# Select a driver, and then click "Properties".
# Observe the driver list in the "Driver Properties" dialog box. If "UniDrv.dll" appears on the list of files, the driver is "Unidrv"-based.

References

* [http://msdn2.microsoft.com/en-us/library/ms802044.aspx Microsoft Universal Printer Driver (UniDrv) MSDN References]
* [http://technet2.microsoft.com/WindowsServer/f/?en/Library/41249604-bd14-41a2-b3e1-67f3a7685e831033.mspx Choosing the right printer drivers (Microsoft)]