Using DEC Operating System for X-Ray Diffraction and X-Ray Fluorescence Analysis

Abstract

The Digital Equipment Corporation (DEC) operating system RSX-11M has recently been installed on a DEC PDP 11/34 computer which is used for the control of, and to acquire and process data from, three X-ray diffractometers, one X-ray fluorescence analysis unit and an electron microprobe. The RSX-11M system replaced the modified DEC 1 - 8 User BASIC previously employed, thus replacing an operating system which was known in detail only to its writer by a system which is supported by the computer manufacturer. There are three major advantages in the use of RSX-11M over 1 - 8 User BASIC: an improved handling of program scheduling, the integration of the software driver for the computer - X-ray electronics interface into the operating system without a major modification of the latter, and the ability of RSX-11M to undertake concurrent execution of instrument control, data acquisition, and data reduction. The 11/34 - RSX-11M system has been implemented to use FORTRAN; a BASIC interpreter has, however, been added which allows users to interact on-line with the computer. A command interpreter which can accept a command line from a terminal has been included.