New microcomputer graphics routines designed for undergraduate teaching

Abstract

INTRODUCTIONMany departments of higher education have bought microcomputers with which to teach thei r introductory courses in program design and development . They have many advantages i n comparison with main-frame and mini-computers : simple-to-understand operating systems , full-screen editors, good response times and, in many cases, colour graphics . Th e student response to using microcomputers is, on the whole, very positive, an d particularly so when programming projects are introduced which use interactive graphics . The use of graphics often motivates the students to produce more imaginative and comple x programs .Graphics is also a very good vehicle for developing a deeper understanding of numerou s topics in science such as population genetics, molecular structure, kinetics, mathematic s and statistics . When used by arts students, it has the same stimulating effect, althoug h for different reasons . In the humanities and arts-based subjects graphics is seen as a way of presenting information in a visual form which greatly increases the effectivenes s of man-machine communication . The importance of graphics in man-machine interaction i s amply demonstrated by the latest developments in microcomputer operating systems a s illustrated by Apple's Macintosh, Digital Research's GEM, and Microsoft's Windows (Swain e 1985) .We have, over the past four years, taught an introductory course in Program Design t o students who are not reading for a computing degree, but who wish to use computing as a tool in their main subjects which range right across the entire spectrum of Highe r Education, including Physics, Geology, Maths, Geography, Psychology, English, French , History and Philosophy . In just this short time span we have used six different model s of microcomputer : RML 380Z, RML 480Z, Victor/Sirius, Apricot PC, Apple Macintosh and R M Nimbus . All machines have a graphics capability, but each has offered a very differen t library of graphics routines . This has meant that the staff have to become proficient i n five different graphics systems, that program examples have to be substantially modifie d for each machine, and that students going on to a second year course have to learn a ne w set of graphics routines . Some might argue that learning more than one system of graphics would be beneficial t o the students, but the educational aim of our courses is not to teach graphics, but t o teach the principles of program design and development . We needed a graphics standar d that was the same for all our microcomputers (as far as the hardware would allow), an d that was quick and easy to learn and use, so that students could concentrate o n developing and designing the program, and would not have to spend too long in grapplin g with an inconsistent and arbitrary set of graphics primitives . Unfortunately there is a variety of very different graphics standards due to the problems outlined by Hopgoo d (1985) . EXISTING de facto STANDARDSIn principle the graphics standard proposed could be implemented for an...