The oberon system

Abstract

In this paper we describe an operating system for a workstation designed and implemented by the authors within two and a half years. It includes memory management and module loader, a file system, a viewer system, editors for text and graphics, a compiler, a server interface and various tools. The primary motivation was to demonstrate the feasibility of a small, yet highly flexible and powerful, system, a system that is a (decimal) order of magnitude smaller than commonly used operating systems. This is possible due to regularity of concepts and concentration on the essential. The benefits are not only fewer resources needed, but elegance and generality of concepts resulting in transparency and convenience of use and increased reliability. A corner‐stone of this approach is genuine extensibility, which is achieved by a new language, in particular by a facility called type extension. It allows for the integration of variables (objects) of a new, extended type in structures of elements of an existing base type.

Adding persistence to the Oberon-System

“…Oberon [WiGu89] is also a run-time environment providing Mark & Sweep garbage collection, dynamic module loading, run-time types, and commands. Commands are procedures that can be called interactively from the user interface by clicking on their names.…”

“…It would be advantageous, however, to add persistence as a general feature to the object-oriented development environment, instead of reimplementing it repeatedly for ever program that needs it. The main contribution of this paper is to demonstrate the ease of integrating persistence into an object-oriented development environment, in our case into the Oberon system [WiGu89].…”

Do the fish really need remote control? A proposal for self-active objects in Oberon

“…Inspired by simulation programming in general and by the Simula language family [3] (the very origin of object-oriented programming) in particular, we have experimented with modelling self-active objects on the Oberon language and environment [4], [5]. The result is a unified framework for concurrent, objectoriented programming.…”

Combining Oberon with active objects

“…In spite of this fact, the Oberon system allows multitasking, but in a very coarse way. As described in [WG92], it is possible to install tasks into the main processing loop. Alternating with the system tasks, i. e. keyboard and mouse handlers which are also part of the central loop, they are executed as a whole, without any scheduling opportunity.…”

“…The Oberon system is a single user and a single process operating system [Rei91] [WG92]. Although very small, it is a very powerful system which is sufficient for almost all applications.…”