Ideas for running a VB4 application on modern hardware?

[mark at markesystems.com]

> I have a Visual Basic 4 application that I need to run on modern 64-bit
> hardware I can do this in a VM, but I really need this VM to be wicked
> small, like under a gig. The smallest XP VM I?ve seen is 600MB (which 
> might
> be good) but XP is becoming very hard to source these days.

VB4 was a bridge between 16-bit Windows 3.1 applications and 32-bit 
everything later (such as the DOS-based Win-95, -98, and -ME, and all of the 
NT-based operating systems, which is everything else through Win-10 64-bit). 
As such, the package included both a 16-bit an 32-bit compiler.  If your 
application was compiled using the 16-bit version, you're pretty much stuck 
with XP-32 or earlier (in a VM, if necessary), as it will automatically 
spawn a 16-bit virtual environment (ntvdm.exe) to run the 16-bit 
applications.  Win7 and beyond, and all 64-bit versions, do not support this 
feature (I supported a VB3 application for 20 years; Win7 was what finally 
broke it for good.)

If it was compiled to 32-bit, then you should be pretty much good to go; you 
may run into a few insurmountable problems with some now unsupported OCX's. 
Other than those, all of the 32-bit code should run fine on anything 
current.

If you have the source, you're also in pretty good shape.  VB4 is very easy 
to port to VB6; there were almost no backward-incompatible features of the 
later Visual Basic classic languages.  Find an old copy of VB6 SP6, 
re-compile it (perhaps replacing some of the failed OCXs with others that 
will work - a common one was DBGrid, which is quite easy to replace with 
FlexGrid), and you're golden.  I currently support just such an application, 
and although the development environment requires a couple of tricks to get 
working smoothly, the compiled application works just fine on Win10-64.

Drop me a note off-line if you'd like any additional or more specific help 
with this; I have a reasonable amount of experience with just this problem.

Of course, there are always older versions of Wine...
~~
Mark Moulding