Laser Printer Language

Laser printers are controlled through page description languages (PDLs). There are two de facto standards for PDLs:

• PCL: Hewlett-Packard (HP) was one of the pioneers of laser printers and has developed a Printer Control Language (PCL) to control output. There are several versions of PCL, so a printer may be compatible with one but not another. In addition, many printers that claim compatibility cannot accept HP font cartridges.
• PostScript: This is the de facto standard for Apple Macintosh printers and for all desktop publishing systems.

For the printer controller and the host computer to communicate, they need to speak the same page description language. In earlier printers, the computer sent a special sort of text file and a simple code giving the printer some basic formatting information. Since these early printers had only a few fonts, this was a very straightforward process.

These days, you might have hundreds of different fonts to choose from, and you wouldn't think twice about printing a complex graphic. To handle all of this diverse information, the printer needs to speak a more advanced language.

The primary printer languages these days are Hewlett Packard's Printer Command Language (PCL) and Adobe's Postscript. Both of these languages describe the page in vector form -- that is, as mathematical values of geometric shapes, rather than as a series of dots (a bitmap image). The printer itself takes the vector images and converts them into a bitmap page. With this system, the printer can receive elaborate, complex pages, featuring any sort of font or image. Also, since the printer creates the bitmap image itself, it can use its maximum printer resolution.

RESOURCES:
WWW.PCWORLD.COM
WWW.PCMAG.COM
WWW.CTV.CONSUMERREPORTS.ORG
WWW.GEEKS.COM
WWW.COMPUTERWORLD.COM