Printer Command Language facts for kids

Printer Command Language, or PCL, is like a special language that computers use to talk to printers. It tells the printer exactly how to put text and pictures on paper. This language was created by a company called Hewlett-Packard (HP) in 1984.

PCL started with early inkjet printers. Over time, it was updated to work with many different types of printers. These include thermal printers, dot matrix printers, and laser printers. PCL became a very common way for printers to understand what to print.

Sometimes, people mistakenly think PCL stands for "Printer Control Language." But PCL is actually a type of page description language. This means it describes how a page should look.

Understanding PCL Levels: From 1 to 5

PCL has gone through many updates, like different versions of a video game. Each new version, or "level," added more features. Levels 1 through 5e/5c use commands that the printer follows one by one. When you print something, your computer's print driver creates these PCL commands.

• PCL 1 was the very first version, released in 1984. It allowed basic text and simple pictures. The quality was up to 150 dots per inch (dpi).
• PCL 1+ was a small update to PCL 1.
• PCL 2 added features for printing business documents and transactions.
• PCL 3 came out in 1984 with the first HP LaserJet printer. It could print better quality pictures (up to 300 dpi). It also supported bitmap fonts, which are like images of letters.
• PCL 3+ (for black and white) and PCL 3c+ (for color) were used in newer HP DeskJet and PhotoSmart printers.
• PCL 3GUI was made for specific HP printers like DesignJet and OfficeJet. It used a special way to compress images.
• PCL 4 was introduced in 1985 with the HP LaserJet Plus. This version added macros, which are like shortcuts for common tasks. It also supported larger fonts and graphics.
• PCL 5 arrived in 1990 with the HP LaserJet III. A big new feature was Intellifont. This allowed fonts to be scaled (made bigger or smaller) smoothly. It also added support for vector graphics, which are images made of lines and shapes.
• PCL 5e (enhanced) came out in 1992. It allowed the printer and computer to talk to each other both ways. This meant the printer could send information back to the computer.
• PCL 5c was also released in 1992. The "c" stands for color, as this was the first PCL version to support color printing.

What is PCL 6?

HP introduced PCL 6 around 1995. It was a big change from earlier versions. PCL 6 is made of three main parts:

• PCL 6 "Enhanced": This part is designed to work best with modern computer screens. It's like a special language for printing from programs that use pictures and icons. It's also compressed to print faster. This part used to be called PCL XL or PXL.
• PCL 6 Standard: This part is like PCL 5e or PCL 5c. It's included to make sure newer printers can still understand older PCL commands.
• Font synthesis: This part helps printers create and manage different fonts. It also stores forms and fonts.

PCL 6 "Enhanced" was built in a way that makes it easier to update for future printers. It can print complex pictures faster and uses less network data. Most of the time, PCL 6 Enhanced is created by your computer's printer drivers. It's not usually used directly by custom programs.

PCL 6 Enhanced is similar to another printer language called PostScript. However, PCL 6 Enhanced uses a special code that computers understand, while PostScript can also be sent as plain text.

PCL 6 Class Revisions

PCL 6 has had several updates, called "class revisions," that added more features.

Class 1.1

This version added tools for drawing shapes like lines, circles, and rectangles. It also supported different colors and ways to compress images. Printers could handle various paper sizes and print on both sides of the paper. It supported both bitmap and TrueType fonts.

Class 2.0

This update added JPEG image compression, which helps make image files smaller. It also allowed printers to send paper to different output trays. More preset paper sizes were added.

Class 2.1

This revision improved color matching. It also added another way to compress images called Delta Row. More paper sizes were included.

Class 2.2

This version added support for JFIF, another common image format.

Class 3.0

This class allowed printers to use different settings for colors in pictures, text, or graphics. It also allowed PCL 5 features to be used within PCL 6 print jobs.

What is PJL?

PJL (Printer Job Language) was introduced with the HP LaserJet IIIsi printer. PJL adds commands that control the entire print job. For example, it can tell the printer to switch between different printer languages. It can also separate print jobs, give feedback on the printer's status, and manage files on the printer.

See also

In Spanish: Printer Command Language para niños

• CaPSL
• Encapsulated PostScript
• Foomatic
• Hewlett-Packard Raster Transfer Language (HP RTL)
• GNU Plotutils
• PostScript Printer Description
• Ghostscript