In DP4 the term printing refers to far more than simply output to a printer. Output is formatted using maps, exactly as when interacting with the user. However, when printing, maps are commonly referred to as forms. Your DP4 program can control the destination of printed output in the following ways:
Your program can pre-select output to any combination of the screen, printer (including devices integrated with the OSDI) or file
You can give the user the option to select an output destination at runtime
You can send initialisation strings to select the paper type, font and other printer control information, or control an OSDI
In the Windows environment, DP4 can use the Windows Print Manager. Printing this way enables you to print using images, colour, and multiple fonts. DP4 does not then need any information about the actual device being used.
Your QA Build and C programs can output to several devices. You can use this facility to manage complex devices such as those used for a POS workstation