There are, however, few situations that justify using a computer as powerful as the 360/44 in a manner just described (i.e., doing nothing but simple addition 100,000 times per second). Therefore, such simple experiments will shortly be handled by means of a link between an existing multichannel analyzer and the computer.
The system does not suffer from having the front end directly connected to the 360/44. The data channel on the 360/44 is sufficiently sophisticated so that it performs all the functions that one might relegate to a small CPU placed between the front end and the 360/44, without any interference with the program currently running in the CPU. The one application described above, which does warrant a separate processor, is handled best by attaching the processor to a separate input port rather than by placing it between the front end and the computer. This enables it to do its intended job without acting as a bottleneck in jobs requiring the power of the front end. It also, incidentally, will function as a completely separate data input terminal if two simultaneous terminals should ever be required.
The particular display system employed has worked very well. Because the display list is in the main memory of the computer, programming of light-pen and other manipulative actions is extremely easy, but at the price of large amounts of memory being tied up. It is clear that the system cannot support two such terminals if they are to be truly independent of each other. It is equally clear that the display is as useful in data analysis as it is in data acquisition. A second display terminal is therefore being added. The selected unit (built by Computer Displays, Inc.) is oriented around the Tektronix 611 storage oscilloscope. It provides both alphameric and graphic display, as well as an interactive device (a cursor moved by means of a joystick) for a price of $8000 to $12,000 plus the cost of interfacing to the computer.
F. MULTIPLE-COMPUTER SYSTEMS
1. Introduction
At the Rutgers-Bell (RB) nuclear physics laboratory, work has been done with two different two-CPU systems. The first of these represented essentially two duplicate processors (Figure 8), and the second, now in the process of implementation, two processors of different size and capability (Figure 9). While full data are not yet available on the actual performance of the second system, an outline of the experience to date will be given.
FIGURE 8 The two-central-processor system of Rutgers-Bell.