Ok, well I have some change sets to load the compiler changes, the base system, the platform pieces. Then load the plugin code, changes etc to interpreter. That all now compiles and links ok. And I can invoke the quicksort sample, then the Objective-C exampleNSOpenPanel but when I try the exampleOpenWindowWithModalAlert I get smoke... However this means it's 90% there. Note classAlien := ObjcAllocateClassPairAlien primFFICallResult: ObjectiveCClassAlien new with: className asAlien with: superclassName asAlien. core dumps but docs say that objc_allocateClassPair takes 3 parms... As indicated below, so mmm clue that something just isn't right objc_allocateClassPair Creates a new class and metaclass. objc_allocateClassPair(Class superclass, const char *name, size_t extraBytes) Parameterssuperclass The class to use as the new class's superclass, or Nil to create a new root class. name The string to use as the new class's name. The string will be copied. extraBytes The number of bytes to allocate for indexed ivars at the end of the class and metaclass objects. This should usually be 0. Return Value The new class, or Nil if the class could not be created (for example, the desired name is already in use). -- = = = ======================================================================== John M. McIntosh <johnmci@smalltalkconsulting.com> Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com = = = ========================================================================