The MCTS operating system
James L. Elshoff, Mitchel R. Ward · ACM SIGOPS Operating Systems Review · 1976
The Multiple Console Time Sharing System, MCTS, implemented at the General Motors Research Laboratories is described. An overview of the logical and physical structures of the operating system is presented.Significant concepts embodied in the operating system are discussed. The system multi-programs among a variable number of tasks, each in an independent virtual memory. A virtual input/output access method is the only one provided. All input/output is performed by polling, no interrupts are used. The operating system is structured exactly like a customer task with only a few special privileges.The MCTS operating system is conceptually simple. The system programmers write in a PL/I-like languaged called MALUS. The system programmers work in an environment very similar to the environment normally associated with an application programmer. The paper discusses the system programmer's environment and some experiences during the development of the operating system.