Accession Number : AD0748828

Title :   SPASTIC - A System for Programming Angles, Scalar, and Timer by Internal Counting.

Descriptive Note : Technical rept.,

Corporate Author : ARMY MATERIALS AND MECHANICS RESEARCH CENTER WATERTOWN MASS

Personal Author(s) : Desper,C. Richard ; Quatieri,Thomas F.

Report Date : JUN 1972

Pagination or Media Count : 36

Abstract : SPASTIC is a modification of the FOCAL interpreter designed to control a simple PDP-8L interface for X-ray diffraction experiments. Control operations are accessed through a set of FOCAL functions which control four stepping motors, an internal data-break scalar, a timer based on a crystal clock interrupt, and the X-ray shutter solenoid. Counting of motor pulses, timer pulses, and scalar pulses are all accomplished within the computer to minimize the interface hardware. The system is used to control an Advanced Metals Research low-angle X-ray diffractometer, using one motor for the 2 theta drive and a second for the attenuator wheel. Programs have been written for zeroing in on the primary beam and for step-scanning through 2 theta, taking data points at various 2 theta intervals. The use of FOCAL permits flexibility in the design of experiments by facilitating the programming and the debugging. (Author

Descriptors :   (*X RAY DIFFRACTION, AUTOMATION), COMPUTERS, COMPUTER PROGRAMS, PROGRAMMING LANGUAGES

Subject Categories : Computer Programming and Software
      Computer Hardware
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE