March 1972 - Vol. 15 No. 3
Features
TENEX, a paged time sharing system for the PDP – 10
TENEX is a new time sharing system implemented on a DEC PDP-10 augmented by special paging hardware developed at BBN. This report specifies a set of goals which are…
The design of the Venus operating system
The Venus Operating System is an experimental multiprogramming system which supports five or six concurrent users on a small computer. The system was produced to test the…
An operating system based on the concept of a supervisory computer
An operating system which is organized as a small supervisor and a set of independent processes are described. The supervisor handles I/O with external devices—the…
A hardware architecture for implementing protection rings
Protection of computations and information is an important aspect of a computer utility. In a system which uses segmentation as a memory addressing scheme, protection can…
Synchronization of communicating processes
Formalization of a well-defined synchronization mechanism can be used to prove that concurrently running processes of a system communicate correctly. This is demonstrated…
A comparative analysis of disk scheduling policies
Five well-known scheduling policies for movable head disks are compared using the performance criteria of expected seek time (system oriented) and expected waiting time…
A study of storage partitioning using a mathematical model of locality
Both fixed and dynamic storage partitioning procedures are examined for use in multiprogramming systems. The storage requirement of programs is modeled as a stationary…
Properties of the working-set model
A program's working set W(t, T) at time t is the set of distinct pages among the T most recently referenced pages. Relations between the average working-set size, the…