This paper proposes a generic system architecture for microworlds that interact with the external real world. It is an extension of our microworld authoring system developed upon the IntelligentPad system. This previous system provides not only tools and objects that its users can easily combine, but also their construction kits, which enable the users to customize or to decompose the given tools and objects, or further to invent new tools and objects. Besides, a user can easily expand his microworld by importing new tools and objects from any other different microworlds. The present system has extended this previous system by introducing a new category of generic pads called proxy pads. They work as proxies of some external objects such as programs running on different machines, or computer controlled electronic or mechanical devices. These proxy pads can represent external objects, especially those in the real world. They can monitor the state and control its changes. This paper proposes the use of proxy pads for real world objects in combination with video pads that monitor their behaviors. This allows users to directly manipulate these objects through their proxy pads and observe their reaction through their video pads as if they are also members in the microworld.