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Calling 16bits DLL from NT4.0

Question asked by VRFuser on Aug 25, 1997

from:  Marco Panzanella
date:  8/26/97
subject: Calling 16bits DLL from NT4.0

     I have already written Per with my explanation but I did not send it to
the V reflector.  The procedure for calling code between 16 and 32 bit functions
is called "Thunking".  In Windows 95 the procedure is called "Flat Thunking". 
Under NT it is called "Generic Thunking".  I have no idea why Microsoft didn't
develop a cross platform solution.  I read an article over dejanews that said
that calling a 16 bit DLL from a 32 bit program in NT is not possible.  The
poster did not say why.  You can do this under Win95 though.  Thunking is not
easy to do.  You can find a procedure on Microsoft's Knowledge Base as Tom
Sanders states below.  Also look through old articles belonging to:  (or something like that).

> We are using VEE 4.01 on Pentium's with NT4.0 installed.
> Has anybody experience in calling 16 bits DLL's from VEE. Our SW engineers
> with windows skills, say that it is troublesome to call a 16 bit DLL from a
> 32 bit application
> Thanks in advance
> Per Bunch
> Test Engineer
> Nokia Mobile Phones, R&D Copenhagen
>I have not done it personally, but after reading what is involved I decided it
>wasn't worth attempting.  You can get info on the method, it's
>called "flat thunking" from the microsoft knowledge base: 
>Name: Tom Sanders
>E-mail: Tom Sanders <>
>Date: 08/26/97     Time: 08:38:40

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