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KnowledgeBase 00015: Using GDI-only printers in Windows
Windows supports two modes of operation for printers; the Graphical Device Interface (GDI) and the non-GDI mode that is frequently referred to as raw mode or text mode.
Essentially, GDI mode allows an application to construct a page as a graphical image enabling use of non-printer resident fonts, etc whereas raw mode simply sends text to the printer.
There is a growing trend, especially for the lower cost printers, for the printer to ship with only a GDI driver. QM uses raw mode by default and the effect of printing in raw mode to a GDI-only device is undefined but often causes the print job to appear in the Windows print queue, apparently complete successfully, but without actually printing anything.
Using GDI Mode
The SETPTR and SET.QUEUE commands both support a GDI option when used on Windows systems. This option causes QM to use the Windows Graphical Device Interface when creating printed output. Although this may at first appear to be a perfect work-around for the lack of a raw mode printer driver, using GDI mode in this way prevents applications sending control codes such as PCL escape sequences directly to the printer and also uses whatever the default GDI font is for the printer.
QM release 3.0-4 added the FONT and FONT.SIZE options to the SETPTR command to set the font name and size for a GDI mode printer.
Recognising that this trend by printer manufacturers not to ship raw mode drivers is causing problems for some applications, several software vendors have created packages that look like raw mode drivers but translate the data output by the application into GDI format.
Ladybridge Systems does not specifically endorse any particular product but we have received good reports regarding DosPrn. Details can be found on the internet at www.dosprn.com.