OS9 device driver in C

The injector accelerators of SPring-8, 1 GeV linac and 8 GeV synchrotron, have distributed control systems using network and many VME computers. These are having many points must be modified after the facility is completed, and the system should be adapted to many requirements of users in a short time and low cost. For this purpose, the concept of object oriented programming(OOP) is inevitable to build up the software. We rewrite device drivers in C to get flexibility, transparency and ease of maintenance. Flexibility and transparency of device access contribute to good achievement of OOP control system. In this paper, the know-how the making device drivers in C and how to combine the C module with the assembler module are described. (author)