ATOMIC1 is an inexpensive O(gigabit) speed LAN built by USC/ISI. It is based upon Mosaic technol ogy developed for fine-grain, message-passing, massively parallel computation. Each Mosaic processor is capable of routing variable length packets, while providing added value through simultaneous computing and buffering. ATOMIC adds a general routing capability to the native Mosaic wormhole routing through store-and-forward. ATOMIC scales linearly, with a small interface cost. Each ATOMIC channel has a data carrying capacity of 500Mbls. A prototype ATOMIC LAN has been con structed along with host interfaces and software that pro vides full TCP/IP compatibility. Using ATOMIC, 1J00 byte packets have been exchanged between hosts at an aggregate transfer rate of more than lGbls. Other tests have demonstrated throughput of 5.25 million packets per second over a single Mosaic channel. This paper describes the architecture and performance of ATOMIC.

The design, implementation, and use of a distributed processing environment on a network of IBM PCs running DOS is described. Temporarily unused PCs can be accessed by other users on the network to perform distributed computations. An owner of a PC need not be aware that the machine is being used during idle times; the machine is immediately returned when the owner begins to work again. Some degree of computation resiliency is provided in this unreliable environment; if a PC is part of a distributed algorithm and is reclaimed by its owner, the system finds a replacement node (if possible), resends the affected code to the processor, and restarts it. Thus, a distributed computation is able to proceed despite a set of transient processors. System performance, distributed applications, and fault tolerance are discussed. Performance improvements are demonstrated by applications like parallel merge sort and a distributed search solution to the eight puzzle.>

This paper extends the rude-CSMA analysis by removing the restriction that each node have the same average arrival rate and average service time. Additionally, some minor errors are corrected.