11. Input-Output Bus Structures
Standardized input-output bus structures designed to simplify interfacing to computers have recently been developed. Conspicuous among them is the CAMAC system already accepted as standard in many European laboratories. It is now being introduced into a few American laboratories. Before it can be accepted as a standard system here, a number of questions must be answered. For example, what types of external devices should be interfaced in this way, just ADC's data registers, counters, and the like, or should line printers, card readers, and related devices be included? Also, how much trouble will be encountered with manufacturers' I/O software, and how much will any necessary rewriting cost? Also will all computer I/O structures lend themselves to such a system; specifically, are multiport systems suitable? A national committee is now studying the CAMAC system to see if it, or something similar, should be recommended as standard in the United States. Even after being recommended as standard, however, any such system cannot be considered successful unless manufacturers accept it and market a wide variety of compatible devices. From the manufacturer's point of view the risks here may seem considerably greater than they were in the case of the NIM bins. It seems wise to keep watching for the outcome of this interesting development.
12. Necessity for Competence in Machine-Language Programming
Whenever a new type of device is interfaced to a system, some form of machine-language programming must almost always be done in order to permit the handling of input-output operations involving the new device. This is true even in places such as Yale, where the design emphasizes a maximum use of Fortran. For this and other reasons, there should be at least one person on call who is skilled in machine-language programming and who understands the system.
13. Manpower for Programming and Maintenance
The manpower required to maintain the hardware and software of any system naturally depends on the size of the installation and the uses to which it is put. Typically, a continuing effort must be expended on the improvement of system software and the writing of new data-acquisition programs. The existing hardware must be given preventive maintenance and repairs. Furthermore from time to time a hardware change must be made. Also, there are administrative matters; even the smallest system should have within the laboratory at least one person who will devote a large part of his time to administration, to the education of users, and to related matters. In many cases the laboratory has a contract with an outside firm, often the computer manufacturer, for maintenance of the computer, and sometimes the rest of the system as well. In other cases all or part of this work is done by laboratory personnel. Sometimes several laboratory people are competent both in machine-language programming and in diagnosing and repairing hardware ills. Such people are very valuable, especially if they are also competent to do interfacing of new devices. In some cases the experimenters do much of their own data-acquisition programming, in others essentially all programming is done by professionals. In some university laboratories much use is made of part-time student programmers, of whom there is now a considerable supply because of the growth of education in programming, both in high schools and at colleges. Students are sometimes remarkably good at this work and stand to profit later from the experience, but they are transients, and effort expended in training them is lost when they leave. Very roughly speaking, a small system will require a good fraction of the time of a technician-programmer, a medium system will require at least one full-time technician-programmer, and a full-time programmer, or some equivalent combination, assuming an active research program.