TITLE
    LaserWriters: Meaning of VMerror & Limitcheck Errors
Article ID:
Created:
Modified:
20681
11/27/96
2/10/99

TOPIC

    Sometimes when I print to my LaserWriter printer, I get an error that there was a VMerror or limitcheck error. What do these errors mean?


DISCUSSION

    The PostScript language does not restrict or limit the sizes or quantities of things described in the language, such as numbers, arrays, stacks, paths, and so on. However, a PostScript interpreter running in a particular printer does have limits: the interpreter in the printer cannot process a printjob that exceed these limits. If the PostScript Interpreter attempts to perform some operation that would exceed one of these limits it may return the error "limitcheck," or "VMerror" if it exhausts virtual memory resources.

    If you print a lot of complex documents to a PostScript printer, you may someday encounter a limitcheck or VMerror error.

    Limitcheck

    The occurrence of a limitcheck error usually indicates the print job itself contains an error or the job has some operation that exceeds one of the printers limits. There are different types of limitcheck errors; the specific limitcheck encountered error is typically listed when the error is reported. Appendix B of the PostScript Language Reference Manual provides an explanation and the typical values for such limits.

    VMerror

    A VM error may occur if the memory becomes too low for the PostScript interpreter to reallocate memory to finish processing a job, or perhaps even provide a more accurate or specific error message, or to display any error message at all. It is impossible to predict accurately how much VM available to the PostScript interpreter a printjob will consume, and though by adding more memory to the printer may resolve a VMerror, there may be other workarounds to printing a complex document as well.

    To workaround limitcheck and VM errors, try:

    - Try reducing unused page size area by printing to US Letter small (or US Legal small) or by removing the check from "larger print area" in page setup options. By reducing the page area, the printer needs less memory to image each page.

    - Try removing all postscript page setup options except for "unlimited downloadable fonts". This will change the way that fonts are sent to the printer to more efficiently maximize the use of memory.

    - Make sure your Macintosh is configured properly, such as you are using the latest or fashionably current version of the LaserWriter driver (which are v8.3.4 and 8.4.1 at the time this article was written).

    - Make sure the proper PPD is selected. Instructions for selecting the proper PPD are listed in the Selecting a PPD File section later in this article. Old versions of the LaserWriter driver prior to LaserWriter 8.x did not use PPDs.

    - If you are printing to an old printer with PostScript Level 1 ROMs, print instead to a printer containing PostScript Level 2 ROMs.

    - Install more memory in the printer, particularly if it is a printer that contains an old implementation of PostScript (PostScript Level 1).

    - Try creating a new document, then copy and past the contents of the old document into the new, then print.

    - If you are using fonts that are non-resident to the printer, fonts not built-in to the ROM, select the Page Setup menu option, "Unlimited Downloadable Fonts in Document." One side effect is this option may be your print times may increase. Alternatively, use fewer non-resident fonts in your document, perhaps one or two typefaces, or merely use the built-in fonts. (A list of resident fonts can be displayed with the Apple Printer Utility, or found in the printer's specification sheet or manual.)

    - Reduce the complexity of the document by removing unnecessary graphics.

    - Cut down on the complexity of the graphics in a document. For example, some programs will "auto-trace" graphics, and sometimes the auto-trace results in excess bezier points. In this example, try hand-tracing the document with an illustration program, or edit out some of the unnecessary points.

    - Reduce the number of graduated fills (fills that go from one color to another in a rainbow-type fashion) in your document, or choose a solid screen or single percentage gray tone.

    - Print the document a few pages at a time.

    - If you notice that the document always stops printing when processing a certain page, try printing that page by itself, then print the pages that follow.

    - Look for corruption in your document. For instance, if only a some pages do not print, look for in those pages a repeating element such as a font or graphic. Try placing that font or graphic on a page by itself and print just that page. If that page will not print, the font or graphic itself may be corrupted, requiring you to reinstall the font or obtain/create a new graphic.

    Selecting a PPD File

    Step 1
    ------
    Open the Chooser

    Step 2
    ------
    Select the LaserWriter 8 driver

    Step 3
    ------
    Locate and select the printer from the printer list

    Step 4
    ------
    Choose Setup. . ."

    Be patient after selecting Setup for a dialog to appear: it may take a little while, particularly if someone else is printing to that printer.

    One dialog may appear stating "setting up PostScript printer." When a PPD has been selected, another dialog stating "Current printer Description File (PPD) Selected: name of PPD" is displayed.

    Step 5
    ------
    Verify the proper PPD has been selected. If the proper PPD was not select, for example Generic is listed as being the selected PPD, click on the Select PPD button, then select the PPD for your printer. If no PPD appears in the listing of PPDs (which are stored in the Printer Descriptions folder), then reinstall the printer software so that the correct PostScript Printer Description file becomes available, then repeat these steps to configure your Macintosh printer driver to use the proper PPD.


    References
    ==========
    PostScript Language Reference Manual, Adobe Systems Incorporated. ISBN 0-201-181274-4

    This article appeared in the 27 November 1996 issue of the Information Alley.

Document Information
Product Area: Apple Software; Printers
Category: LaserWriters
Sub Category: General Topics

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