Frequently Asked Questions on PowerStation for MS-DOS

The information in this article applies to:

• Microsoft FORTRAN PowerStation for MS-DOS, versions 1.0 and 1.0a

SUMMARY

These are the answers to 20 of the most commonly asked questions about Microsoft FORTRAN PowerStation for MS-DOS.

MORE INFORMATION

1. Q. When I attempt to build a project using the PowerStation Visual
      Workbench, I get an error dialog box that says:

         Internal error. Timed out waiting for "C:\F32\BIN\WINTEE.EXE"
         to start.  Please contact Microsoft Product Support Services

      What can I do to correct this problem?

   A. The problem is probably caused by a Windows configuration
      setting that causes Windows-based applications to get 100
      percent of the computer's processing time whenever a
      Windows-based application is active. This causes MS-DOS-based
      applications to fail to run whenever a Windows-based
      application is running. To correct the problem, from the Main
      program group, start the Control Panel application. Choose the
      "386 Enhanced" icon. Be sure that the Exclusive In Foreground
      check box is not checked. Choose OK to return from the dialog
      box, and close the Control Panel application. The problem should
      now be corrected.

2. Q. My PowerStation application writes data to a binary file. Why
      is the amount of data in the file less that what I expect?

   A. There is a problem with output to binary or unformatted files
      with FORTRAN PowerStation. If your code writes arrays larger
      than 64K in size to a binary or unformatted file and the array
      is specified in the output statement without using an implied
      DO-loop (or only a simple, single-dimension, implied DO-loop),
      then the amount of data that will be output to the file is the
      size of the array modulus 64K.

      To correct this problem, use an explicit implied DO-loop for the
      array in the input or output statement. The array index
      expression in the implied DO-loop must be more than a simple
      variable. For example, change "array sub i" to "array sub i plus
      zero." The functionality is the same but the more complicated
      expression causes the compiler to generate the correct code.

3. Q. When I use the PowerStation's Visual Workbench to compile and
      build programs, it takes a very long time to compile and link.
      What can I do to improve this process?

   A. The system requirements state that you must be running MS-DOS
      and need 4 megabytes (MB) of available memory with 6 MB or more
      preferred. If you have only 4 MB of physical memory, then under
      Windows you probably have less than 4 MB of physical memory
      available and are intensively using your Windows swap file. Make
      sure that your swap file is as large as it can be and that you
      are using a permanent swap file. You can also decrease the
      amount of memory that SMARTDRV or any other disc caching
      utility is consuming. The most effective solution is to add
      more physical memory to your machine.

4. Q. I used to do mixed-language programming with high-level languages
      (such as C) and FORTRAN. Can I do this with FORTRAN PowerStation?

   A. Yes. Object modules compiled with Microsoft Visual C++ 32-bit
      edition, can be linked with FORTRAN PowerStation. For more details,
      please see the information in the F32\SAMPLES\MIXED_C directory. 16-
      bit C/C++ object modules (created by earlier versions of Microsoft C
      or Visual C++ 16-bit edition) can not be linked with 32-bit FORTRAN;
      these must be recompiled with a 32-bit compiler.

      For complete support of mixed 32-bit C and FORTRAN programming,
      Microsoft offers development tools for Windows NT: Visual C++ 32-bit
      edition and FORTRAN PowerStation 32 for Windows NT. Microsoft Windows
      NT is a true 32-bit operating system (in contrast to a 32-bit DOS
      extender on top of 16-bit MS-DOS) allowing full integration between
      the two languages. Mixing of C and FORTRAN is also possible in a pure
      16-bit world, such as MS-DOS or Windows, with Microsoft FORTRAN 5.1
      and Microsoft Visual C++ 16-bit edition.

5. Q. Can I do Windows executable or Windows dynamic-link library
      (DLL) programming using FORTRAN PowerStation?

   A. FORTRAN PowerStation for Windows creates only 32-bit MS-DOS-
      extended MS-DOS applications. FORTRAN PowerStation32 for Windows
      NT will create Win32 executables and DLLs.

6. Q. I have some FORTRAN code that reads a file that used to work
      with Microsoft FORTRAN version 5.1. The code now gets an error
      when it is almost finished reading the file. What is the
      problem?

   A. Earlier versions of Microsoft FORTRAN had some limited support
      for end-of-file handling using the "CTRL+Z" character. This
      character, which is number 26 in the ASCII table, is placed in
      files by some editors and some other file creation utilities.
      FORTRAN PowerStation no longer treats this character as a
      special character and gives an error message when attempting to
      read it into a variable. Make sure that files being read by
      FORTRAN PowerStation programs do not contain this character,
      which resembles a small right-pointing arrow when displayed by
      editors capable of displaying all characters in a file. This
      was an unintended loss of functionality with the product and is
      under investigation.

7. Q. When I run my program on a machine with lots of memory I get no
      error. But when I run it on a machine with less memory I get
      the run-time error:

         DOSXMSF : fatal error DX1020: unhandled exception: Page fault

   A. This is an MS-DOS-extender error that indicates that the program
      attempted to access memory that was not owned or allocated by
      the program. A common cause of this error is an array subscript
      going out of the array's declared range. An attempt to access
      an array beyond the range of the array does not cause the
      DX1020 error to occur immediately. On machines with less
      physical memory (RAM), this error occurs more often because any
      attempt to access virtual memory on the disk will cause an
      initial nonexception page fault; however, if the request for memory
      is invalid, the DX1020 error will occur. Check the code
      carefully to be sure that all array access uses an array index
      within the proper range. Also, use the /4Yb compiler option to
      install some additional debug error checking. This can be set
      in the Visual Workbench by choosing Project from the Options
      menu and then choosing the Compiler button. Select the category
      Language Extensions and the option Extended Error Handling.

8. Q. When I use the PowerStation debugger under the Visual
      Workbench, it sometimes proceeds very slowly and occasionally
      acts erratically. What can I do to improve this situation?

   A. The system requirements for FORTRAN PowerStation states that
      the product requires 4 MB of available memory. This is an
      absolutely minimum requirement. Under Windows, the PowerStation
      tools may not perform optimally without an adequate amount of
      Windows swap file. Make sure that you have the largest Windows
      swap file that it is possible to have. The most effective way to
      improve performance of the PowerStation tools is to add
      physical memory (RAM) to your machine. For optimal performance
      while debugging make sure that you are not running any other
      applications. In particular, make sure that you are not running
      any other MS-DOS applications or MS-DOS prompts.

9. Q. My program runs for some time and then I see intensive disk
      access. It takes a long time to terminate or I see the error,
      "F6700 Heap Space Limit Exceeded."

   A. There is a known memory leak with the PowerStation product,
      which is caused by having a string concatenation inside of an
      IF statement. Assign the string concatenation to a intermediate
      variable and use that variable in the IF statement instead of
      the concatenation itself.

     getting the results I expect or why don't I get the results that
     I got under FORTRAN version 5.1?

   A. There are two known problems with COMPLEX variables that could
      result in incorrect results. The first problem is that logical
      expressions that compare COMPLEX variables for inequality can
      fail under some circumstances. These are expressions such as IF
      (Q.NE.Z) where both Q and Z are COMPLEX variables. If either
      the real or the imaginary elements are the same in both
      variables then the .NE. will fail to detect that the other
      elements are different and will return .FALSE. To avoid this
      problem, use the logical equivalent to .NE. of .NOT.(Q.EQ.Z).

      The second problem occurs if a REAL function, including the
      FORTRAN intrinsic functions, is assigned to a COMPLEX variable.
      To resolve this problem, assign the REAL function to a REAL
      intermediate variable and then assign that variable to the
      COMPLEX variable.

11. Q. I get linker errors that start with LNK. Where can I find more
       information about these errors?

    A. The LINK32 errors are available in the ERRORS.HLP Windows Help
       file and in the ERRORS.TXT ASCII text file. Access to
       ERRORS.HLP is available only from Windows. You can bring up
       this file from the Visual Workbench by selecting the Help menu
       and choosing Search For Help On. Type in "errors" in the Help
       Keyword text field and then choose OK. You can also access the
       file by opening the File Manager and double-clicking the
       ERRORS.HLP file in the \F32\HELP directory.

       The ERRORS.TXT file is in the F32\README directory. It can be
       read or printed from MS-DOS or Windows like any other text
       file.

12. Q. I am getting some errors that begin with DX. Where can I get
       more information on these errors?

    A. The DX errors are Phar Lap DOS-extender errors and are
       available in the ERRORS.HLP Windows Help file and in the
       ERRORS.TXT ASCII text file. Access to ERRORS.HLP is available
       only from Windows. You can bring up this file from the Visual
       Workbench by selecting the Help menu and choosing Search For
       Help On. Type in "errors" in the Help Keyword text field and
       then choose OK. You can also access the file by opening the
       File Manager and double-clicking the ERRORS.HLP file in the
       \F32\HELP directory.

       The ERRORS.TXT file is in the F32\README directory. It can be
       read or printed from MS-DOS or Windows like any other text
       file.

13. Q. In FORTRAN version 5.1 there is an option, /Fs, to create a
       source listing file. Can I do this with PowerStation?

    A. No, the PowerStation product does not support the source
       listing option. Most of the functionality of source listings is
       available though different options in the Visual Workbench.
       Source browser information, for example, provides a visual
       means of locating variable definitions and references.

14. Q. I created a project with the PowerStation Visual Workbench and
       several of my source files have include statements. When I
       modify one of these include files and then build the project,
       the source file does not recompile. Why isn't there a build
       dependency for the include files?

    A. You are probably using the $INCLUDE metacommand and not the
       INCLUDE statement in your source files. The Visual Workbench
       build engine does not create dependencies for files on $INCLUDE
       metacommands. Change all the metacommands to FORTRAN statements
       and then force the project to rescan dependencies by selecting
       Project and then choosing Scan All Dependencies.

15. Q. I am getting the following error:

          LINK32 : error LNK2133: Size mismatch for symbol  and the
          symbol listed in the error is the name of one of my COMMON
          blocks.

       What is causing this error?

    A. You probably have a COMMON block declared with arrays of
       different sizes in different source files. In one source file
       you are initializing the COMMON block with a DATA statement.
       You must have the object file from the source file that
       initializes the data in the COMMON block in the link command
       before any other object file from a source file that references
       the COMMON block. Moving the object files in the link order
       will prevent the error from occurring. If you are using a
       Visual Workbench project, change the filename of the source
       file that initializes the COMMON block to a name that is
       alphabetically prior to all other source filenames. This will
       force the build to include the object file first on the link
       command line.

16. Q. Sometimes when I start up the PowerStation Visual Workbench I
       can't see some of the windows I had set up when I closed it;
       they are listed in the Windows menu, but I can't see or access
       them. What happened and how can I see my windows again?

    A. You probably had the inaccessible child windows minimized
       within the Visual Workbench frame and then closed the Visual
       Workbench while it was itself minimized. This can easily happen
       if you exit Windows when the Visual Workbench is still active
       and minimized. To avoid this problem, never exit the Visual
       Workbench application when it is in a minimized state when the
       Visual Workbench still active. You can make any inaccessible
       child windows visible by selecting the Window menu and choosing
       Cascade.

17. Q. When I try to use the PowerStation Visual Workbench browser I
       get the error:

          Cannot open the browser database file. Share is not installed
          or is not active for this drive.

       How can I avoid this error?

    A. The Visual Workbench browse utility requires that SHARE.EXE, an
       MS-DOS file access arbitration utility, is installed prior to
       starting Windows. The easiest way to do this is put the
       statement "C:\DOS\SHARE" in your AUTOEXEC.BAT file. Make sure
       that you put the SHARE command before any line in the
       AUTOEXEC.BAT that says "win" or "dosshell."

18. Q. How does virtual memory work under the PowerStation product? Is
       there any way I can change this functionality?

    A. PowerStation virtual memory management is considerably
       different depending on whether you are running your application
       under MS-DOS or under MS-DOS under Windows.

       If you run your PowerStation application under MS-DOS, virtual
       memory is managed by the Phar Lap DOS-extender. When your
       application loads into memory, all declared data must load into
       memory. If you don't have sufficient available extended memory,
       the DOS-extender will use virtual memory on the disk where
       DOSXMSF.EXE is located. This process is automatic and requires
       no interaction on the part of the program. If you want to
       relocate the location used for virtual memory, you can set the
       DOSX environment variable with the command:

          SET DOSX=-SWAPDIR X:\MYSWAP

       Note that X: is the drive/partition you want to use and MYSWAP
       is the directory you want to place the virtual memory file in.
       If you want to turn off use of virtual memory, you can set the
       DOSX environment variable as follows:

          SET DOSX=-NOVM

       If you are running your program under an MS-DOS session under
       Windows, then virtual memory is managed by Windows. You can
       control the size and type of your Windows swap file by starting
       the Control Panel application and selecting the 386 Enhanced
       icon. Please consult your Windows documentation for further
       details.

19. Q. I am compiling and linking in two separate steps from the
       command-line. When I go to run the executable file I get the
       error:

          This program cannot be run in DOS mode.

       What did I do wrong?

    A. PowerStation applications use an MS-DOS-extender so there is an
       additional step required to allow the executable to run under
       MS-DOS. You need to run the BINDMSF.EXE utility on your
       executable to install a small piece of code called a
       "stub-loader." For example, if you had an executable file
       called MYEXE.EXE, you would use the command line:

          BINDMSF MYEXE.EXE

20. Q. Can I run the PowerStation product under OS/2?

    A. No, FORTRAN PowerStation does not run under or target OS/2 or
       the MS-DOS-compatibility session under OS/2. Under the MS-DOS-
       compatibility session, the MS-DOS-extender has a problem that
       prevents it from working correctly.