The Macintosh computer uses an internal language called QuickDraw to create and display text and graphics on the video screen. Most printers, however, expect data from the computer in a different language (like PCL, PostScript, etc.). A printing extension is a Macintosh file which works with application programs to convert text and graphics from QuickDraw to the desired printer langauge. The extension is also responsible for managing the communication between the Macintosh computer and the printer. The name “extension” is used because it extends the functionality of the basic system software. Printing extensions are also sometimes called “drivers.”
What is “Laser Prep”?
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The “Laser Prep” file is a PostScript dictionary of commands which older printing extensions use to print your job. This file is downloaded into the printer by the printing extension before the first job is printed. This is called “Initializing the Printer.” The printer stays “initialized” until it is turned off. With the Apple “LaserWriter” printing extension version 7.0 and the HP LaserJet printing extensions which are based on that version (installable from this disk), the contents of the “Laser Prep” file are built-in. With these newer extensions, a separate “Laser Prep” file is not needed.
What are “laser wars”?
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Printing extensions and their accompanying “Laser Prep” files are matched sets. For example, the version 6.x series of the “LaserWriter” extension requires a series 6.x “Laser Prep” file to be downloaded to the printer. Similarly, version 7.x extensions require their own built-in “Laser Prep” to be downloaded. Since the printer can only be initialized with one “Laser Prep” at a time, a problem can occur if Macintoshes with different printing extension versions try to print to the same printer on a network. Any time a mismatch is detected by the printing extension, an error is displayed and the user is asked if the printer should be reinitialized. This annoying phenomenon is referred to as laser wars.
The only way to avoid this problem is to ensure that the same version of the appropriate printing extension is installed on all Macintosh computers that will be sharing a network printer so the “Laser Prep” contents will match.
So, which printing software should I use?
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To use your HP LaserJet printer with your Macintosh computer, you must install the appropriate printing extension on your system. If your HP LaserJet printer will be shared with other Macintosh computer users on the network, regardless of the system software version they are running (System 6 or System 7), then all of those users must install and use the same version of the printing extension. If any user tries to print using an older LaserWriter or LaserJet driver, the laser wars phenomenon may result.
Installing the LaserJet printing extension on your Macintosh computer:
Insert the “HP LaserJet Printing Tools” disk into the floppy drive on the target Macintosh computer. If necessary, double-click on the disk icon to open its window. To install the appropriate printing extension, double-click the “Install XXX” icon (where XXX represents your LaserJet model). Click OK at the Hewlett-Packard screen and follow the “Easy Install” instructions that appear. The installer first examines the system to determine which pieces of software need to be installed. These recommended components are listed for you, and all you need to do is click the Install button and follow the on-screen instructions. If you want some combination of the available components other than the recommended set, click the Customize button.
