One approach for building the next generation of parallel computers is based on large aggregates of multiprocessor chips with support for hardware multithreading. An initial design for IBM's Blue Gene/C project exemplifies this approach. Such a machine might consist of a million processors, and is characterized by a low memory-to-processor ratio. To study alternate programming models for such a machine before it is built, we have developed an emulator that allows million-processor programs to be run on conventional parallel machines with hundreds of processors. Here we present the implementation of a parallel object model based on Charm++ as a candidate programming model. Although the "ideal" programming model for such machines is a matter of continuing research, we believe that parallel objects represent a good starting point. This paper reviews the target architecture, presents the programming model, and describes the emulator implementation. Case studies of simple applications written using the emulator are also discussed.