Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

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 Product Compatibility
 
 ■ Visual Basic for MS-DOS is compatible with all previous versions of
   Microsoft QuickBasic.
 
 ■ The following compatibility guidelines apply when porting applications
   from Visual Basic for Windows:
 
   • The content of a global module should be translated to a comparable
     $INCLUDE file. You must include this file in each file in your project
     using the $INCLUDE metacommand. See: ◄$INCLUDE Metacommand►
 
   • Formal parameters and all Dim, Dim Shared, Redim, Static, and Global
     statements must be changed to include appropriate AS clauses.
 
   • Functions used in Visual Basic for Windows code (.BAS) modules require
     insertion of the appropriate DECLARE FUNCTION statements in each file in
     your Visual Basic for MS-DOS project.
 
   • Insert the statement "CALL Main" in your project if your Visual Basic
     for Windows application uses "Sub Main" as the startup.
 
   • Visual Basic for Windows custom control (.VBX) files are compatible
     with Visual Basic for MS-DOS.
 
   • The table below defines the most common statements and declaration
     relationships between Visual Basic products:
 
         Visual Basic for MS-DOS          Visual Basic for Windows
         ══════════════════════════       ══════════════════════════════════
         COMMON SHARED X                  Global X
 
         DIM X(A TO Z)                    Global X(A to Z)
         COMMON SHARED X()
 
         COMMON SHARED X()                Global X()
 
         ON LOCAL ERROR                   On Error
 
         DIM SHARED                       Dim statements (declaration level)
 
         STATIC X()                       Static X(A,B,C)
         REDIM PRESERVE X(A,B,C)
 
 ■ For additional information on product compatibility and portability, refer
   to the appendixes in the "Programmer's Guide."
 
 See: ◄Compatible Languages►