MICROPROCESSOR AND MICROCOMPUTER EDUCATION

REFERENCES

[11 L. A. Leventhal, "Education in microprocessors and microcom-puters," in Proc. DISE Workshop on Microprocessors and Educa-tion, Aug. 1976, pp. 68-70.

[21-] "Microprocessors in computer education," Computers andPeople,pp. l1-15,Oct. 1976.

[31 ,"Microprocessors: A new tool for science teachers," CollegeStudent J., pp. 298-302, Winter 1976.

[41 -, "Introducing microprocessors into engineering curricula,"presented at the 1976 Fall CECC Conf., Costa Mesa, CA, Nov.1976; also J. Data Processing Education, to be published.

[5] -, "An introductory course in microprocessors and microcom-puters," Comput. Education Trans., to be published; also to bepresented at the 1977 ASEE Conf.

Microprocessors in an Interdisciplinary Project Course

RONALD KRUTZ, MEMBER, IEEE

Abstract-A description of microprocessor projects in an interdisci-plinary engineering project course is presented and some practical con-

clusions and recommendations for conducting such a course are

discussed.

A three-course sequence of problem-solving courses has beeninstituted at Carnegie Institute of Technology of Carnegie-Mellon University (CMU). The courses involve analysis, syn-

thesis, and evaluation, and are therefore designated ASE I,

ASE II, and ASE III. These courses provide a new emphasisto the Carnegie plan of professional education which has beenthe educational philosophy of Carnegie-Mellon University forover 30 years. The ASE courses are designed to have the stu-dents approach a relevant engineering problem and develop a

solution within technical, social, economic, and time constraints.ASE III is the final course in the sequence and consists of a

number of projects which require the solution of realistic prob-lems involving the skills and techniques of more than one engi-neering discipline. The projects in the course are related by a

common theme and groups of approximately five junior or

senior engineering students work on a particular project.In the Spring of 1976 the theme of ASE III was "Micropro-

cessors in Engineering" and all five of the course projects in-cluded microprocessors as an integral part of the problem solu-tion. The Fall 1976 offering of ASE III was entitled "Engi-neering of Railroads" and one of the six projects undertakenutilized a microprocessor in the problem solution. The pur-

pose of this short paper is to briefly describe the micropro-cessor projects and to present some conclusions relative tomicroprocessors in a project course.

PROJECTS (SPRING 1976)

1) Microprocessor control ofautomated foundry cleaningmachines: The purpose of this project was to design and im-plement a microprocessor-based controller for use in conjunc-tion with steel foundry cleaning machines. This particularASE III project was primarily concerned with the removal ofgates, risers, and runners from the casting by use of a machinein a "learn and repeat" mode of operation. For project pur-

poses, a modified Sears radial arm saw with system hydraulic

Manuscript received July 12, 1976; revised January 7, 1977.The author is with the Department of Electrical Engineering,

Carnegie-Mellon University, Pittsburgh, PA 15 213.

drives which is under development at the CMU Processing Re-search Institute was used as the machine to be controlled.2) Dual mode vehicle system: The dual mode vehicle system

is an experimental mass transit system that allows a variety ofvehicles to be operated either under driver control or automaticelectronic control. The dual mode vehicle is a standard vehiclewith the addition of an electric traction motor for motivepower, two guidance arms for steering and power pick-up, andan electronic control system for motor, brake, and guidancecontrol when the vehicle is on the controlled highway. Controlfunctions for the system are divided between a highway con-troller and on-board controllers on each vehicle. The projectobjective was the development of these controllers usingmicroprocessors.3) Explosive gas monitor: The project was concerned with

the use of solid state detectors to accurately determine the con-centrations of methane and carbon monoxide in the presenceof other gases in a coal mine. The problem is that currentlyavailable solid-state gas detectors are very poor in selectivity,have widely varying sensitivities, and are not manufacturedwith uniformity of characteristics. The project utilized a mi-croprocessor with an array of solid-state gas detectors in orderto "intelligently" interpret the data from the multiple detectorsand thereby improve the selectivity and reproducibility of thedetection process.4) A solar heating system: This project had two goals. One

was to design a solar thermal experimental facility controlledby a microprocessor and the other was to design and build a"proof-of-concept" model of a solar heating system with dataacquisition and control accomplished by a microcomputer.The model was to provide verification and component testingcapability to support the design of the experimental facility.5) Microprocessor-controlled traffic light: The design of a

microprocessor-based intersection traffic controller that couldbe used at a variety of intersections was the objective of thisproject. Optimization of traffic flow, stops per vehicle, andlost travel time were used as the bases for the control algorithm.In order to test the resultant software and hardware, a trafficsimulator based on an actual complex intersection was built.

PROJECT (FALL 1976)

The use of a microcomputer to control railroad switchingand signaling was evaluated by this project. The problem re-quired the control of a main line on which a minimum offour trains were operating, at least one of which was travelingin the opposite direction from the others. The main line wasspecified to have four sidings and associated switches withwhich to send a train into a siding. The solution was imple-mented using an HO gauge oval track with four trains, foursidings, and associated switches and sensors.

CONCLUSIONS1) Use preassembled microcomputer cards instead of chips.

2) The preassembled cards should have monitor programs inROM to aid in programming and debugging. 3) If possible, atwo or three day anticipatory "crash course" on microproces-sors should be given to the students and advisors to allow themto spend more of the course time solving the given problem in-stead of learning about microprocessors. 4) Utilize existingavailable equipment on which to base projects so that the stu-dents can immediately begin work on the project. 5) Developindustrial contacts to serve as advisors to the students. 6) Eventhough it would be highly desirable to allow the students toselect the microprocessor to be used, support requirementsusually require that the microprocessor be specified before thestart of the course. Then, assemblers, editors, and simulators

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IEEE TRANSACTIONS ON EDUCATION, MAY 1977

can be in readiness for use by the students. 7) Cross-assemblersand simulators run on an in-house minicomputer are an excel-lent way to support the software development. An alternativeis to use microcomputer development systems. This alternativecan be expensive (-$4000 per development system) unless ar-rangements can be made to borrow these units from a distribu-tor or manufacturer. 8) Terminals such as a Teletype or TISilent 700 are a necessity for the course. Unavailability ofdata entry devices is usually a major bottleneck in a micropro-cessor project course. 9) In one semester, it is a monumentaltask to complete a microprocessor-based project if hardwareand software are to be operational at the end of the term;therefore design and parts ordering decisions must be madeearly in the course.10) Students should prepare a time sched-ule of task completions and a budget and adhere to both.11)Progress report presentations should be made by the groups totheir peers and interested faculty and industrial personnel.

ACKNOWLEDGMENTThe projects, under the supervision of their advisors, were

coordinated by Dr. D. Tuma and Dr. G. Dieter.

A Microcomputer Interfacing Course

RUSSELL J. NIEDERJOHN, SENIOR MEMBER, IEEE,GARY W. LARSEN, MEMBER, IEEE, ANDDANIEL M. RITT, STUDENT MEMBER, IEEE

Abstract-A hands-on undergraduate laboratory course is describedin which microcomputer hardware and practical digital integrated cir-cuit design are taught in a motivating and educationally efficient man-ner. Each student in the course is given the task of designing an inter-face between an Altair 8800 microcomputer and an input-output ormemory device. As a result of two offerings of the course nine input-output devices and three memory types have been interfaced to thesystem. The educational advantages and the results achieved throughthis approach to microcomputer hardware education are discussed.

I. INTRODUCTION

The accelerating impact and importance of microcomputers(and microprocessors) cannot beoverlooked in an up-to-dateengineering or computer education. There are a number ofapproaches which can be taken to microcomputer educationdependent upon the educational goals of the particular curric-ulum. In an electrical engineering curriculum, one essentialpart of this education is a hands-on laboratory experiencewith microcomputer hardware.While there are a number of approaches to a hands-on labo-

ratory course on microcomputer hardware, the approach de-scribed in this paper has proven to be both highly motivatingand educationally efficient. This approach is based upon theindividual design, in a team environment, of an interface be-tween an Altair 8800 microcomputer system and any of anumber of input-output devices. Each student enrolled in thecourse is independently assigned an input-output device forwhich he is responsible for developing the interface. This de-velopment consists of the individual design, hardware assembly,test, and documentation of the completed project. Thus, eachstudent becomes involved with the whole design process.The course to be described is offered at Marquette University

as a special section of a required, senior level, digital laboratory

Manuscript received October 18, 1976; revised January 21, 1977.This work was supported by the National Science Foundation underGrant HES75-12536 and the Department of Electrical Engineering,Marquette University.The authors are with the Department of Electrical Engineering,

Marquette University, Milwaukee, WI 53233.

course (one four-hour laboratory period per week). All studentsenrolling in this special section are required to simultaneouslyenroll in a concurrently offered minicomputer-microcomputerassembly language programming course (senior elective course).No particular background in digital logic circuits is required.As a result of two offerings of the laboratory course, the fol-lowing interfaces have been built and are completely opera-tional: 120 character/s paper-tape reader, two A/D converters,two D/A converters, vectored interrupt facility, incrementalplotter, CRT graphics terminal, CRT character terminal, ASR-33 teletype, programmable clock, 2 K static RAM, 8 K dynamicRAM, and 2 K erasable ROM.The microcomputer system chosen for use in this laboratory

course is the Altair 8800 system, manufactured by MITS.1This particular system is well constructed, has complete docu-mentation available, has a flexible I/O bus which has becomesomewhat of an industry standard, is relatively inexpensive,and is based upon a very popularly used microprocessor (Intel8080). Two Altair 8800 computers are used. One has an es-pecially constructedI/O socket mounted on top of the cabinetand is used solely for debugging interface designs. This socketis so constructed that interfaces may be plugged into it in onlythe correct direction and so as to be convenient for testing anddebugging hardware interfaces. The other Altair 8800 is thepermanent home for each of the interfaces after they havebeen tested and found completely operational. This computersystem has an extendedI/O bus to facilitate up to nine inter-faces. In addition, it has plugs mounted to the rear of the cab-inet to allow the connection withI/O devices.

II. COURSE DESCRIPTION

A brief description of the course is given here, a more de-tailed description can be obtained from the authors.Prior to the beginning of the course for a particular semester,

feasible projects are chosen, necessary hardware is ordered,and a detailed time schedule is constructed. This time scheduleincludes the sequence of activities which each student is ex-pected to pursue as well as check points whereby these activi-ties can be monitored. Such check points include informalmeetings with the course instructor and the graduate assistantassigned to the course as well as two formal meetings of theclass as a whole. These two formal meetings are central to thegoals of the course. They are held after roughly one-third ofthe semester and near the end of the semester. At these 2meetings each student is expected to present a10 to 15 minoral description of his project. At the first meeting this oraldescription includes a detailed description of his particularinput-output device and a rough description of his intendedinterface design organization. At the final formal meeting,each student is expected to describe and demonstrate hisworking interface. These two formal meetings serve two mainpurposes. First, they promote an exchange of ideas betweenclass participants and provide a means for broadening eachstudent's experience with microcomputer hardware and I/Ointerface design. Second, these two formal meetings providethe course instructor with a method of feedback for monitoringthe understanding and progress of each student.At the first class meeting of the semester the details of the

course organization and the time schedule prepared previouslyare described to the class participants. It is pointed out howeach student will have an individual interface project for whichhe will be solely responsible. Once this project is assigned(fourth class period), each student will be given the freedom todesign the interface as he chooses. Other than the two formalclasses and the four introductory lectures, each student is freeto work on his interface and utlize the laboratory facilties attimes of his choosing. A responsible attitude on the part of

1MITS, 6328 Linn NE, Albuquerque, NM 87108.

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