Programming semantics for multiprogrammed computations
Communications of the ACM
| Hi-index | 22.14 |
The central core of a real-time computer control system is the operating system which handles the allocation of the computer resources. Any real-time operating system can be shown to have a fundamental structure and data base. In implementing such a system for a given application, a subset of the general form and data base is used in order to efficiently handle the given application, decrease the time spent in the executive, and reduce the size and storage requirements. However, in doing so one changes the flexibility and ease of using the system. It is these trade-offs and assumptions which we study in this paper. We shall look at three systems: the GE Real-Time Multiprogramming Operating System (RTMOS), the IBM 1800 Multiprogramming Executive (MPX) and the XDS Sigma 5 Real-Time Batch Monitor (RBM-2). It will be shown that each of these three systems has certain parts that are more flexible than the others. However, it would not be economical, desirable, nor practical for a process control size system to have the same degree of flexibility in all parts. It is shown that each of these systems has a balance between capability, flexibility and time response. The discussion will primarily show that there exists a commonality of structure and of necessary information even though the three systems were developed completely independently of each other.