This thesis represents an exploration into the field of numerical control (NC), and an investigation into the area of engraving/profile milling process. Chapter two gives an introduction to NC and outlines of operation and field of application. The great its modes benefits of NC are found to be in contouring processes such as welding, milling, knitting, etc... The engraving/profile milling process can now be included as trolled engineering application. numerically con a The background and current state of the art is presented. Relevant advances in microelectronics are described and their impact on NC assessed. The trend is now towards NC systems using microcomputers as their controlling units. The reason for this lies in the price decrease of semi-conductors, particularly in the area of microprocessors and memories storage devices. The versatility of or microprocessors and microelectronics provides equipment manufacturers and end-users with enhanced flexibility to customise these systems to their particular requirements. The design methodology and development of such systems are presented (chapters 4,5,6,7). For example, circular engrav ing is discussed (chapter 4) and the substitution of human operator by electronics equipment for the control system is explained. Subsequently, a system for templates, notices, etc., is developed with minor software changes. Besides the versatility of microcomputers and . microelectronics, the ability to customise software as well as hardware can lead to better and confident of more use these systems,resulting in reduced product lead times and better product quality. The design approach and initial development of such practice are presented (chapter 10). Unlike most of the commercial systems present in the market, the system developed integrates the two main fields of engraving/profile milling process, whereby a product can be designed, graphically edited,visualized, draughted and finally produced. The software, which consists of a cor porate graphics package with dedicated hardware, is highly versatile and flexible. For instance, the system can be used to accommodate variety of machining operations ranging a from engraving, milling, drilling, wood-working, punching, continuous welding and any contouring engineering applications. The importance of computer graphics is stressed and the applications of techniques developed in this area are shown. For instance, for interactive creation and editing of char acters, the implementation of the EDITOR program brought with it further advantages. A contour be sketched by \ can hand, the first step in tracing, and further the data exam ined to decide on possible set of points from which to edit the contour. Most noticeable was the problem encountered with editing high quality characters low resolution on display devices. Again the application of computer graphics techniques (zoomingt scalingt clipping etc...) to this prob lem provided a very efficient solution with extra cost savings. With respect to the creation and the production of characters computers it can be said that no particular on method is well suited to all purposes (section 10.2 ). How evert accuracyt storage requirementt flexibility and speed considerations advocate the use of curves on order more no than twOt straight segments and circular arcs being the best choices.