A novel architecture for use within an end computing system is described. This attempts to extend the concepts used in modern high speed networks into computer system design. A multimedia workstation is being built based on this concept to evaluate the approach. 1 Introduction High speed networks (100Mbit/s per access point) are currently being designed and coming into use as local area networks (LANs). The desire to support traffic with real time requirements (e.g. multimedia traffic) has lead many groups to propose the use of Asynchronous Transfer Mode (ATM 1 ) for such networks. In the longer term the adoption of ATM by Broadband ISDN (B-ISDN) will give wide area ATM coverage. The effective use of these networks depends on the design of end systems which can utilise the bandwidth provided. The real producer or consumer of the data will be a particular processor or device within the end system, so besides considering the design of a network interface, consideration must be given to...