Best bits: Applications of microprocessors: Outguessing gases

In semiconductor fabrication, processes such as chemical vapor deposition require a control panel to coordinate gas flow into and out of the chamber where chips are kept. Engineers must monitor the pressure of the chamber continually and manipulate theexchange of dangerous gases carefully. Formerly they wired a panel for each process controlled, keeping track of pressure and gas exchanges by reading dials and turning valves at the right moment. Now, however, a microprocessor-based panel can be programmed to control these processes more safely and without operator error, according to its manufacturer, the Tylan Corp. of San Mateo, Calif.