Creating a Learning Object Design Model. A Model for Redesigning Existing Learning into Learning Objects

Amoeba is based on the client-server model. Clients are typically written by the users and servers are typically written by the system programmers, but users are free to write their own servers if they wish. Central to the entire software design is the concept of an object, which is like an abstract data type. Each object consists of some encapsulated data with certain operations defined on it. File objects have a READ operation, for example, among others. Objects are managed by servers. When a process creates an object, the server that manages the object returns to the client a cryptographically protected capability for the object. To use the object later, the proper capability must be presented. All objects in the system, both hardware and software, are named, protected, and managed by capabilities. Among the objects supported this way are files, directories, memory segments, screen windows, processors, disks, and tape drives. This uniform interface to all objects provides generality and simplicity. All the standard servers have stub procedures in the library ...»