The Environment

[This is preliminary documentation and subject to change.]

Developers working on Win64-based applications will find the environment virtually identical to the environment for Win32-based applications. The API is the familiar Win32 API. Many of the functions have been modified to allow them to reflect the precision of the platform on which they are running. The result is simplicity and a short learning curve for the developer—writing code for 64-bit Windows is just like writing code for 32-bit Windows.

The Platform SDK supports new data types that allow pointers and pointer-associated variables to reflect the precision of the platform. This means that developers can compile a single source base to run natively on either Win32 or Win64 systems. This strategy reduces the cost of developing applications that leverage 64-bit hardware, such as the Alpha chip from Compaq or the forthcoming IA-64 chip from Intel. When 64-bit Windows becomes available, simply recompile your Win32 code and test it on 64-bit Windows.

You will have more time to make your applications 64-bit ready if you adopt the new data-type conventions as soon as possible. If you are making maintenance changes or Windows 2000–specific changes to your code, you should change the data definitions at the same time. Test the application in a familiar environment (Win32), run it through the 64-bit compiler (described in The Tools), and the application will be ready when 64-bit Windows is available.