The future is upon us. As I write this, Microsoft is hard at work porting the Windows 2000 kernel so that it is a true 64-bit operating system. The expected title is 64-bit Windows 2000, and the expected ship date is the year 2000. Initially, this 64-bit kernel will run on Compaq's Alpha CPU architecture (AXP64) and Intel's new 64-bit CPU architecture (IA-64).
Compaq's Alpha CPUs have always been 64-bit architectures. So if you already own an Alpha machine, you will just need to install 64-bit Windows 2000 when it ships in order to run a full 64-bit operating system. Intel's Pentium series (and earlier) CPUs use a 32-bit architecture (IA-32). Machines with these CPUs cannot run 64-bit Windows 2000. Intel is currently designing a new 64-bit CPU architecture. The first chip to use this architecture is code-named Merced. Machines based on the Merced CPU should ship in the year 2000.
64-bit Windows 2000 interests me a great deal, and I have been preparing my code for this day. Today Microsoft's Web site has a number of articles about 64-bit Windows 2000 and how it will look to software developers. I'm happy to report the following:
Since Microsoft's Web site offers much information on how to modify your existing source code to be 64-bit ready, I will not go into those details in this book. However, I thought about 64-bit Windows as I wrote each chapter. Where appropriate, I have included information specific to 64-bit Windows. In addition, I have compiled all the sample applications in this book using a 64-bit compiler, and I was able to test the applications on a very early version of 64-bit Windows for the Alpha CPU. So, if you follow the sample applications in this book, and do as I've done, you should have no trouble creating a single source-code base that you can easily compile for 32-bit or 64-bit Windows.