This vo1~e contains the papers presented at the NATO Advanced Study Institute of New Advances in Distributed Computer Systems held between 15th and 26th June, 1981 at the Chateau de Bonas, France. The aim of the meeting was to promote an interchange of ideas between experts in the inter1inked fie1ds of communications and computers in order to determine the essential areas for future deve1opment. Its programme was arranged to exp10re a number of current topics inc1uding the pub1ic data-communication networks set up by the PTTs or corresponding bodies in various countries, 1arge-sca1e non-pub1ic systems such as ARPANET and its 1atest deve1opments, international systems such as the air1ines’ SITA network, the recent and very important deve10pments in loca1 area networks and relevant deve10pments by universities and other higher educationa1 bodies. The recent moves towards form- isation and the 1aying down of a theoretica1 basis to guide future deve10pments and standards were discussed with particu1ar reference to the International Standards Organisation 7-1ayer model for Open System Interconnection and the deve10pment of formal mathematica1 methods for specifying and ana1ysing communication systems and their protoco1s. Consideration was also given to the theoretica1 techniques, and their practica1 realisation, now becoming avai1ab1e to ensure privacy and security of information transmitted over digital communication systems. Fina11y the penetration of the concepts of distributed processing into the domain of computer architecture, giving such possibi1ities as array processors and other non-von Neumann architectures formed the subject of severa1 of the sessions.