Beamline Computer Control by Interpreter

The computer control system for the K9 separated beam is described. This beamline is a multi-energy/ multi-particle beam and the principal aim of the computer system is to reduce the time taken to tune the beam to a new energy. The hardware comprises a 12K PDP-8 with disc and magnetic tape, a Teletype and logging typewriter. Control of the magnet currents and collimators is via a multi-crate CAMAC system, which also serves for data acquisition. The software system is based on a real-time, high level language interpreter. Besides allowing the users to write their programs in a high level language (similar to FORTRAN), the interpreter also provides all the executive functions required with a disc-based, real-time system. Because an interpreter is used, programs can be written or modified on-line and tried out immediately. The relatively slow execution speed of the interpreter is no disadvantage. The system allows high level language and machine code program segments to be combined in any program.