Digital computer hardware

The advent of third generation digital computer hardware together with recent advances in computational chemistry based on molecular quantum mechanics and statistical mechanics combine to make the structure of molecular liquids accessible to theoretical study at new levels of rigor via computer simulation. There is presently broad based research activity in this area from quite diverse points of view in physics and chemistry. 

In order to prepare the system for 3D-CT, it is not enough to integrate a second detector array. Besides this special attention has to be paid to the computer hardware, the synchronisation between object movement and the data read out as well as to the collimator of the LINAC. The collimator has been built with 4 tungsten blocks which can be moved individually m order to shape different sht sizes for 2D-CT as well as different cone angles for 3D-CT or digital radiography. 

Computer Hardware. The use of a computer for data acquisition and control is mandatory because of the clock frequency used by the Reticon array (20 kHz) and the volume of data that it is capable of outputting. A PDP-8e computer made by Digital Equipment Corporation, with 12 K words of memory was employed. 

Calibration of both computer hardware and digital-to-analog converters, power supplies, and field instraments. 

The next two sections of this chapter treat the technical history of computational chemistry, namely the development of the hardware, concepts, and methods used in the field. We discuss first the chemists earliest uses of the computer as a research tool in the 1950s. The first stored program electronic digital computers became available in the early 1950s in chemistry, as in other branches of science, these devices were initially deployed as calculating engines. Next we deal with the expansion of the field of computational chemistry during... 

Describe the structure of a conventional digital computer, and identify the characteristics of each hardware component in this structure. 

Chapter 26. An excellent reference on the various hardware and software aspects of digital computer control systems is the series of monographs edited by D. A. Mellichamp and published by CACHE ... 

As the titles of the monographs indicate, the reader can find in this series a storehouse of information on every aspect of process computers discussed in Chapters 26 through 30 of the present text. Particular attention is drawn to monographs III and IV, dealing with the hardware components and architecture of digital computers, as well as monographs V and VI, covering all important software aspects for control applications. 

The controller This is the hardware element that has intelligence. It receives the information from the measuring devices and decides what action should be taken. The older controllers were of limited intelligence, could perform very simple operations, and could implement simple control laws. Today, with increasing use of digital computers as controllers, the available machine intelligence has expanded tremendously, and very complicated control laws can be implemented. 

If you were to use a digital computer as your controller in the control configurations of item 8, what new hardware elements would you need ... 

In the preceding two sections we gave a brief description of a digital computer and its characteristics, of the associated peripherals, and of the I/O interface required for data acquisition and control. In this section we examine the various types of control loops that result when a digital computer is used as the main controller, as well as the necessary hardware components. 

Figure 26.5 Hardware components of digital computer control loop.

Finally, two books from chemical engineers provide useful but limited material on digital computers and their hardware and software features ... 

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