Correctness of realizations of levels of abstraction in Operating Systems.- A simulation model representing the OS/VS2 Release 2 Control Program.- Une analyse de systeme par typologie.- Equivalence and decomposition methods with application to a model of a time-sharing virtual memory system.- The specification of process synchronization by path expressions.- A foreground-background time sharing queue with general service times.- Espace d'adressage et espace d'exécution du systeme gemau.- A new approach to avoidance of system deadlocks.- A program structure for error detection and recovery.- Analyse de quelques pannes d'un systeme d'exploitation.- An open operating system for a single-user machine.- Evaluation sur des modeles de comportement de programme de la taille d'un ensemble de travail.- Schedulers as enforces in synchronization processes.- Caractérisation fonctionnelle des systemes de fichiers.- Presentation of the control graph models.- The Edinburgh Multi-Access System scheduling and allocation procedures in the resident supervisor.