This thesis is concerned with a design of a closed-loop microprocessor based control system for a glass fiber chemical vapor deposition (CVD) machine.Current CVD machines require extensive operator skills and intervention in the manufacturing process. From one to seven operators are typically employed. Controllers are single, open loops that are in general,unreliable and inflexible. The CVD process itself is undertaken by only a few companies and a substantial body of knowledge on controlability is lacking.A fully automatic closed loop microprocessor system is described in this thesis. Its design involved a comprehensive characterization of the CVD process, designing an operator interface, selecting the hardware design and implementing the software. In addition, goals were set with respect to reliability, maintainability and extensibility. A complete system was built and tested.Results of field trials indicate that the process can be controlled with minimal operator intervention, a single operator can simultaneously control up to eight CVD machines. Reliability and maintainability goals have been met. The operator acceptance has been high.