64-bit talking to 32-bit DLL?

[Insider1984]

Hi guys. I have a motion controller which is nothing more than a serial port device. The dll is old and written in 32-bit. I have an "interface" dll which wraps and does a DLL import on the DLL itself (along with a few other motor controller dlls to make a common interface).

On a 64-bit PC. if the application is compiled in 32-bit.... everything works great. If it is compiled in 64-bit the call into the manufacturer's 32-bit fails. If I try to compile my interface in 32-bit but the application in 64-bit the application exceptions when it enters the function that calls to the dll.

the exception is something about "the wrong format".

I would guess there is a way around this but a search online didn't return much.

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Insider
4 year 'on the fly' programmer
C, C++, C#, MFC, Basic, Java ASP.NET

 

[chiph]

Hmmm. This ought to work, as the Wow64 runtime ought to create a 32-bit thunk for you.

But anyway, a workaround would be to create a 32-bit assembly that does your interfacing with the DLL. You can then create a 64-bit solution that references it. You'd have to manage two solutions (one 32-bit, one 64-bit), but the call between them ought to be transparent to you.

Chip H.


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