Page description languages

A page description language works just as its name says it does. It describes the whole page being printed by sending commands that describe the text as well as the margins and other settings. The controller in the printer interprets these commands and turns them into laser pulses (or pin strikes). 

Also, with graphics, the commands to draw a shape on the page are relatively complex. For example, to draw a square, the computer (or printer) has to calculate the size of the square and convert that into lots of "strike pin x" (or "turn on laser") and "print nothing" commands. This is where the other types of page description languages come into the picture. 

Another page description language is the Printer Control Language, or PCL. Currently in revision 5 (PCL 5), it was developed by Hewlett-Packard for its LaserJet series of printers as a competitor to PostScript. PCL works in much the same manner as PostScript, but it s found mainly in Hewlett-Packard printers (including its DeskJet bubble-jet printers). Other manufacturers use PCL, however. In fact, some printers support both page description languages and will automatically switch between them. 

When you need to print, you select the printer driver for your printer from a preconfigured list. The driver you select has been configured for the type, brand, and model of printer as well as the computer port to which it is connected. You can also select which paper tray the printer should use, as well as any other features the printer has (if applicable). Also, each printer driver is configured to use a particular page description language. 

I n this chapter, we discussed how the different types of printers work as well as the most common methods of connecting them to computers. You learned how computers use page description languages to format data before they send it to printers. You also learned about the various types of consumable supplies and how they relate to each type of printer. 

Which of the following are page description languages (Select all that apply.)... 

B, D. Of those listed, only PostScript and PCL are page description languages. 

One important aspect of using graphics is the ability to produce hardcopy -- that is, to print it. Here, there seems to be only one logical choice PostScript [18]. This page description language is widely used in the HEP community and is a de facto industry standard many software vendors provide for PostScript output from their i)rograms. PostScript supports color, and has the merit that the files are ASCII, and so can readily be transported, and can even be edited. 

PostScript. PostScript is a page description language developed by Adobe Systems Incorporated. Today, most word processors and desktop publishing systems support PostScript as one of their output formats. Most laser printers and many document production systems support PostScript as input. An extension of PostScript, called encapsulated PostScript, creates an output format which can be imported into some document production systems as a way of integrating information from different systems. PostScript is not strictly an interchange format, since the imported material in encapsulated PostScript cannot be edited, merely printed. This may change in the future. 

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