A closed loop controller has a measurement server which captures measurement data from a measurement machine via a link. Both of the two address transition detecting signal generating modules have a unilateral delay circuit for generating an output pulse at the rising edge of the address signal and an output pulse at the falling edge of the address signal. a user interface module; and a testing module for providing an integrated testing environment within a software development system. The system also can include a selective power management module coupled to the computer and configured to selectively apply power management to only one of the displays in which a period of inactivity is detected, while not applying power management to remaining ones of the displays. Two separate discharge chambers are provided, one of which is a part of a master oscillator producing a very narrow band seed beam which is amplified in the second discharge chamber.