18.1 Overview

The Win32 implementation is still in a state of development. It is expected that changes will be necessary when MIT/GNU Scheme is ported to Windows NT on the DEC Alpha architecture. In particular, the current system is not arranged in a way that adequately distinguishes between issues that are a consequence of the NT operating system and those which are a consequence of the Intel x86 architecture. Thus this documentation is not definitive, it merely outlines how the current system works. Parts of the system will change and any project implemented using the win32 system must plan for a re-implementation stage.

The Win32 implementation has several components:

• Special microcode primitives.
• A foreign function interface (FFI) for calling procedures in dynamically linked libraries (DLLs).
• An interface for Edwin.
• The Win32 package provides support for using the features of the Windows 3.1 and Windows NT 3.1 environments.
• Device Independent Bitmap utilities. These are used by the win32 Scheme Graphics implementation. (The Scheme Graphics implementation is described in the Reference Manual).

Note that all the names in the Win32 support are part of the win32 package. The names are bound in the (win32) environment, and do not appear as bindings in the user or root environments. An effect of this is that it is far easier to develop Win32 software in the (win32) package environment or a child environment.