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    Microsoft Product Support Services Application Note (Text File)
          DV0599: COMPILING AND LINKING QUESTIONS AND ANSWERS
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                                                   Revision Date: 8/92
                                                      No Disk Included

The following information applies to Microsoft Visual Basic for MS-DOS
version 1.0.

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|                                                                    |
| Copyright 1992 Microsoft Corporation. All Rights Reserved.         |
| Microsoft and MS-DOS are registered trademarks and Visual Basic    |
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1. Q. How do I modify a Quick library?

   A. It is not possible to modify an existing Quick library. To add
      routines to a Quick library, you must re-create it. For more
      information on how to create a Quick library, please refer to
      Chapter 19 of the "Programmer's Guide."
  
2. Q. LINK.EXE (the linker) continues to generate the error
      message "R6907 DOSX16: not enough memory on exec." What is
      causing this error?

   A. LINK.EXE version 5.31.009, which is provided with Microsoft
      Visual Basic for MS-DOS, tries to use expanded and extended
      memory by default. If either type of memory is low, that is, less
      than 200K is available, it is possible that the linker can fail
      and generate the error message "R6907 DOSX16: not enough memory
      on exec."

      To work around this error, use the /r switch as the first option
      on the link line; /r must immediately follow "LINK" for this
      switch to be effective. The Visual Basic for MS-DOS (VBDOS)
      environment, VBDOS.EXE, checks for this condition and adds /r to
      the link line for you. This forces the linker to ignore expanded
      and extended memory and run in conventional memory only.
     
      To work around this problem without using the /r switch, you must
      make more expanded and/or extended memory available to the
      linker. This may involve changing the settings for your expanded
      memory manager. If you are running Visual Basic in an MS-DOS
      session within Microsoft Windows, you must change the PIF
      settings for that MS-DOS session.

3. Q. My program runs in the Microsoft Visual Basic for MS-DOS
      (VBDOS) environment; however, when the program is compiled, an
      "out of memory" message is generated. How can I correct this
      problem?

   A. If a program runs successfully in the VBDOS environment but runs
      out of memory at compile time or run time, there may be a problem
      with arrays. In the VBDOS environment, arrays are dynamic by
      default. This means that the arrays are created at run time and
      are stored in far memory. In a compiled application, arrays are
      static by default. This means the arrays are created at compile
      time and are stored in near memory (DGROUP), of which there is
      only 64K.
     
      To make all your arrays dynamic in a compiled application, use
      the metacommand REM $DYNAMIC at the beginning of your program
      before the dimension (DIM) statements of your arrays. If you have
      any arrays that are included in COMMON SHARED statements, the DIM
      statements in which they are included.
     
      For more information on the $DYNAMIC command, please refer to the
      "A-Z Reference" in the "Reference" manual.
     
      For more information on memory management, please refer to
      Appendix B of the "Programmer's Guide."

4. Q. When I try to compile my program, I receive a "program
      memory overflow" error message. How can I correct this problem?

   A. If a program runs successfully in the Visual Basic for MS-DOS
      (VBDOS) environment but generates a "program memory overflow"
      error message at compile time, the program needs to be broken
      down into multiple modules.
     
      In the VBDOS environment, each subroutine, function, event, or
      module-level code is allocated 64K for code. In a compiled
      application, the entire file is allocated only 64K. This
      difference allows a much larger code module or form to run in the
      environment than can run in a compiled application.
     
      To make your compiled programs run, you must reduce them in size
      by moving some code to another module. For more information on
      multiple-module programming, please refer to Chapters 6 and 16 of
      the "Programmer's Guide."