🚀 go-pugleaf

VB/DOS Pro has every language feature that Basic PDS 7.1 with the following
exceptions:

1.  VB/DOS Pro has a new OPTION EXPLICT directive that tell the environment
and compiler to enforce that variables must be declared (e.g. DIM foo as integer)
before used.  Stops typos.  This is optional so the default is such that you
can still say something like x=2 anywhere and it works.  This can be set at the
module level so different modules in one project can be configured differently
(handy for mixing old code w/ new code)

2.  VB/DOS has 386-specific code generation.  The first Microsoft compiler
to offer this feature.

3.  VB/DOS Pro does not use the same monolithic overlay system that Basic PDS
had.  Rather, it uses the multiple in-memory overlay system that Microsoft
C/C++ 7.0 uses -- MOVE.

4.  VB/DOS Pro stores string literals (like PRINT "Steve") in FAR MEMORY
when compiled.  Basic PDS stored these in precious dGroup.

5.  VB/DOS Pro has no OS/2-specific features and cannot compile an OS/2-specific
.EXE file.

6.  VB/DOS, like VB/Win, uses Far Strings only.  The vast majority of all
commercial addon packages already use Far Strings so this should be no
problem for most people.  FWI -- Far Strings allow VB/DOS to use all the
DOS memory your machine has available, near strings are limited to 64K
of total string space.  Far strings have also been highly speed tuned for
real-world code so, in most real (as opposed to contrived benchmarks)
apps, Far strings are at least as fast as near strings.

7.  Of course, VB/DOS also uses the same forms/events/controls model that
VB/Win pioneered.  That's why VB/DOS is highly compatible with VB/Win.
At the same time, you can create apps that are a hybrid of both existing
QB/PDS procedural and new VB-style event code.
Thanks, Steve Podradchik, Product Manager, Microsoft VB for MS-DOS