BARTON McLEAN, THE UNIVERSITY OF TEXAS-AUSTIN

"The Fairlight CMI and Its Uses in Advanced Laser Graphics" The Electronic Music Center at the University of TexasAustin is currently experimenting with a laser beam deflection system connected to and driven by the Fairlight CMI. With this system, complicated light patterns may be drawn on the CMI screen to complement a musical performance. Not only can images be displayed statically, but with the Fairlight's flexibility the images may be made to increase or decrease in size, rotate, distort, and even slowly merge into new images. The basic setup is similar to traditional x-y laser deflection systems with two mirrors driven by galvanometers, producing Lissajous figures, What is different with the Fairlight setup? If, instead of sinewaves, two voltages which are parametric functions of time are applied to the "x" and "y" inputs, any figure which can be drawn by hand without lifting pen from paper can be produced by the laser system. The Fairlight allows us to create such functions by "drawing" the desired function on its screen with a light pen. It then translates the drawn function into an analog output voltage which drives the galvanometers. During the beginning stages of our investigation, and to give us needed practice, we created various letters of the alphabet. These were than stored and reproduced, providing the capability of one image merging into another, and then another, etc., thereby allowing for a continual change in the image.