Automatic Chain Cleaner

The Automatic Chain Cleaner (ACC) is a battery-powered tool that clamps onto a bicycle frame and encloses the chain while cleaning it with brushes and degreaser and/or water. The batteries power a motor that drives the chain in the reverse direction from normal bicycle use. Clamps stabilize the tool and provide a consistent and stable cleaning job. This project aims to replace the manual versions of thistool which suffer from lack of stability and a poor user experience. Ease of use and reliability are important requirements for this project. The ACC will take 4 AA batteries and will run smoothly and consistently due to the electric motor.This report details the entire design process, starting from defining the problem and ending with the final prototype and performance results. Extensive modeling and analysis was conducted using computer-aided design (CAD) in Solidworks. The final result had many changes from the initial prototypes, but vastly improved upon the first designs with multiple rounds of testing and refactoring. 3D printed PETG plastic was used for all parts except the motor and 11-tooth driving cog, which was taken from a bicycle cassette. Videos at the end demonstrate the ACC working smoothly and showcase its stability

The Sprite Internet Protocol Server

This report describes the design and implementation of the DARPA Internet protocol suite for the Sprite network operating system + . The Sprite implementation is based on the 4.3BSD kernel implementation, but most of the code is placed in a user-level process called the IP server. Compared to a kernel-level implementation, a user-level implementation is simpler to debug and test but performance is adversely affected. Throughput performance of TCP on Sprite is about 25% of 4.3BSD TCP throughput using the same hardware. TCP latency on Sprite is about 14 times 4.3BSD's latency. 4.3BSD socket compatibility is achieved with a set of library routines that emulate socket system calls. ########################### + This work was supported in part by the Defense Advanced Research Projects Agency under contract N00039-85-C-0269, in part by the National Science Foundation under grant ECS8351961, and in part by General Motors Corporation. Sprite Internet Protocol Server December 1987 1. Intro..

The sprite network operating system

Sprite is a new operating system for networked uniprocessor and multiprocessor workstations with large physical memories. It implements a set of kernel calls much like those of 4.3 BSD UNIX, with extensions to allow processes on the same workstation to share memory and to allow processes to migrate between workstations. The implementation of the Sprite kernel contains several interesting features, including a remote procedure call facility for communication between kernels, the use of prefix tables to implement a single file name space and to provide flexibility in administering the network file system, and large variable-size file caches on both client and server machines, which provide high performance even for diskless workstations