Richard R. Eckert

A Microprogrammed Computer Simulator

A software educational tool (ET) has been developed that enables students of computer architecture to simulate a wide variety of computers on a fixed microprogram-organized-hardware (MOH). The user defines a computer by using ET to enter the appropriate microprogram. Machine language programs (macroprograms) may then be entered and a simulation made of their execution on the computer defined by the microprogram. While the simulated run is occurring, the state of the underlying machine may be observed at any point of execution. A microstep/graphics run mode may also be used to present a color display of the data path section of the MOH after each microinstruction is executed. In this paper, the ET simulation program, the MOH machine, and a simple example of how ET is used are presented.

Microprogrammed computer simulator tools

A versatile microassembler and assembler program is described that was developed to facilitate the preparation of symbolic microprograms and assembly language programs for use with the microprogrammable computer simulator ET (educational tool) previously reported by the authors (see ibid., vol.E-30, p.135, Aug. 1987). The microassembler program takes as input a microprogram source file written in symbolic form and produces files ready for loading into the simulators control ROM and address ROM. In addition, a file containing the mnemonics and corresponding op-codes of each instruction in the instruction set of the machine being simulated by the microprogram is created. The assembler program uses this file together with a user-written symbolic assembly language source program and produces a file containing machine language object code ready for loading into the simulators RAM. Both the microassembler and the assembler also produce list files that may be examined by the user. Students of computer architecture indicate that use of these tools, in conjunction with the ET simulator, greatly simplifies the task of learning how microprogrammed computers function. >

Three-dimensional computation visualization for computer graphics rendering algorithms

Computation visualization or algorithm animation is becoming an increasingly popular and effective way of teaching, debugging, and analyzing algorithms. Over the past ten years, several algorithm animation systems have been produced. Proposed here is a new approach and framework for visualizing three-dimensional algorithms or computations. Implemented on a prototype algorithm animation system, this framework, termed the vector-guided view, produces insightful visualizations of three-dimensional computation by effectively solving the problems of 3D scene navigation. The creation of this framework was motivated by the desire to produce visualizations of an increasingly large and complex set of rendering algorithms now ubiquitous in the field of computer graphics. To show the potential of this framework, a dynamic visualization of a recursive ray-tracing program has been created. A brief summary of the algorithm animation system is presented.

Teaching concepts in fuzzy logic using low cost robots, PDAs, and custom software

Fuzzy logic is a topic traditionally taught in artificial intelligence, machine learning, and robotics courses. Students receive the necessary mathematical and theoretical foundation in lecture format. The final learning experience may require that students create and code their own fuzzy logic application that solves a real world problem. This can be an issue when the target is a bioengineering course that introduces classical control theory, fuzzy logic, neural networks, genetic algorithms and genetic programming through the use of a low cost robot, personal digital assistant (PDA) handheld computer, and custom PDA software. In this course, the concepts and theories discussed in lecture are reinforced and extended in a corresponding laboratory through the use of wireless robots and PDAs. Fuzzy logic libraries and software modules for laptops and desktop computers are readily available, however, when it comes to handheld computers no such libraries exist. Students are able to spend more time experimenting with different fuzzy logic controllers when a custom fuzzy logic library and PDA graphical user interface are utilized. In this paper we introduce and discuss a unique low cost wireless robot, a custom fuzzy logic library, a custom fuzzy logic GUI for the PDA, and the implementation results for the fuzzy logic section in a newly created bioengineering course. Diagnostic and summative assessment in the form of a pre-test and post-test was administered for each section of the course, however, only the results for the fuzzy logic section will be provided.

Kicking off a course in computer organization and Assembly/machine language programming

For several years I have been teaching a sophomore/junior level cours e entitled Computer Organization and Programming . The objectives of the course are to introduce machine organization and teach students to progra m in assembly language . Although there are many fine text books on assembl y language programming and several good books on computer organization, I have not been able to find one that combines the two subjects so that the y are meaningful to beginning students . It has been particularly difficul t to start off the course in an interesting and challenging way without losing these students, who, for the most part, have been exposed only t o introductory high level language programming . Recently I have tried a n approach that shows signs of being successful . The heart of the approac h is the use of a simple fictitious computer to illustrate the basi c concepts . Although this approach is not completely new, I feel that th e simplicity of the computer used along with the fact that the material i s presented so early in the semester make it rather unique . In this paper I describe the machine and how it is used in the first class of the semester .

Microcomputer data entry in epidemiological research

Abstract The use of an inexpensive mark sense card reader as a data entry point for a Radio Shack TRS-80, Model I microcomputer is described. IBM-like cards marked in pencil with epidemiological data from a public health survey are fed into the reader interfaced to the microcomputer. The complete procedure and a computer program which accepts the card data input, deciphers it, and stores it in manageable form on diskette are explained in detail.

Microcomputer-controlled plotting of environmental health data

A general microcomputer program has been developed which facilitates the preparation of finished plots of geographical and temporal variations in such data as: the concentrations of suspended airborne particulate matter and of metallic and organic components detected in the particulate; the incidences of several kinds of respiratory illnesses and symptoms; epidemiological information obtained from physicians, hospitals, pharmacies, and schools. Examples of plots produced by the program, detailed explanations of how it works and a complete program listing are included.

Algorithms for vector graphic optimization and compression

The objective of metafile compositing is to retrieve multi-layered Windows Metafile command records from a picture file and translate them into a set of closed contours in a single layer that delineates a set of contiguous non-overlapping regions. Such processing is useful for a variety of engineering applications including vector graphic compression and optimization which is discussed here. Primary concerns here are the multitude of degeneracies that exist when implementing a geometric algorithm of this nature. These issues are left largely unaddressed in previous literature but can be of substantial importance when attempting to develop a robust implementation.

Communication between computers and peripheral devices—an analogy

In most courses in computer organization an important topic is that of communication between the cpu and input/output devices. Some of the relevant issues are: synchronous versus asynchronous exchange of information, handshaking, and interrupt-driven versus programmed I/O (polling). After having taught such a course for several years, we have found that students tend to become confused as soon as we get to the point of attempting to explain how the various status and control signals between the processor and the perlpheral device work to manage the transfer of data. For that reason we have developed an analogy that simplifies and makes more understandable the subject of parallel communication.

Exchange of environmental health information between microcomputers

Programs have been developed which permit the transfer of disk files (programs or data) from a TRS-80, Model-III microcomputer to a TRS-80, Model-I system via an RS-232-C serial interface. The programs allow researchers to effectively use both computers in the entry and processing of air pollution and epidemiological data, in addition to facilitating the exchange of programs, data, and word processor documents between users of the two machines. A detailed explanation is given of how the programs control the RS-232 hardware and use several of the file management routines in each computers operating system to achieve successful information transfer.