It is a fact of life that the needs of general-purpose-computing drive microprocessor trends. Simple semiconductor-fabrication economics makes mass-marketable designs very inexpensive, while making designs aimed at smaller market segments, such as CNC, cost prohibitive.
　　“Advances in technology help all technologies in a general way,” says Paul Nickelsberg, president and chief technical officer at Orchid Technologies Engineering and Consulting Inc. [www.orchid-tech.com]
　　The underlying “big i

ron” at the heart of any CNC machine has been under development for hundreds控制工程网版权所有, or even thousands, of years. The basic lathes, mills, drills控制工程网版权所有, etc., were designed in manual form at the dawn of technology.
　　Starting in the mid-20th Century, and accelerating thereafterCONTROL ENGINEERING China版权所有, technology was developed to substitute servomotors for geared axis drives (numerical control — NC), with computers calculating intermediate data points for the servos by interpolation from waypoints (computer numerical control — CNC). As computer technology advanced from vacuum tubes to discrete transistors to integrated circuits to, finally, microprocessors, these new developments rapidly found their way into CNC machines.
　　“Enhancements in microprocessor technologyCONTROL ENGINEERING China版权所有,” says Roger Hart, manager of real-time software R&D with Siemens Energy and AutomationCONTROL ENGINEERING China版权所有, [www.sea.siemens.com] “have allowed more functions to be added to the CNC, and they have allowed CNC performance to be improved.”
　　“These widely used chips and microprocessors provide a very scalable platform and enough performance at any level,” says Karl Rapp, manager of automation and machine tool branch at Bosch Rexroth. [www.boschrexroth-us.com] “Since the software and firmware is developed for this platform, CNC OEMs can easily provide control solutions that run on the processor of the machine HMI.”
　　The bad news
　　The bad news is that sometimes there is a disconnect between what CNC machine technology needs and what general-purpose computing provides. For