A CAMAC Branch Driver for the Varian 620 Series Computers

A CAMAC branch driver for the Varian 620 series computers has been designed and built by Kitt Peak National Observatory for use in several real time control and data acquisition systems currently being assembled. Its principal feature is a stack register which serves as a work area to assemble the information needed for a CAMAC cycle. The stack has sixteen levels which serve to preserve the existing status under interrupt conditions without requiring special software routines. A priority interrupt system with 23 levels and a direct memory access channel are also included. The system is self contained, needing no auxiliary support within the host computer. Highlights of the structure and general characteristics are described below.