Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!uwm.edu!ux1.cso.uiuc.edu!iuvax!purdue!mentor.cc.purdue.edu!pur-ee!pur-phy!murphy From: murphy@pur-phy (William J. Murphy) Newsgroups: comp.sys.amiga Subject: Amiga 1000 in Computers in Physics Message-ID: <3050@pur-phy> Date: 31 Jan 90 14:57:59 GMT Reply-To: murphy@newton.physics.purdue.edu.UUCP (William J. Murphy) Organization: Purdue Univ. Physics Dept., W. Lafayette, IN Lines: 42 Last night I was reading my most recent issue of Computers In Physics. One of the feature articles was about tracking the blood flow in the retina using a laser doppler velocimetry technique. A second technique that was used in a quantifiable subjective test was a comparison of stimulating the subjects retina with blue light. When stimulated, the subject will perceive white dots seemingly in random motion. The dots (this is only my recollection of the article) are caused by white corpuscles moving through the capillary structure and network of the retina. The researchers quantified this motion using an Amiga 1000 performing a realtime animation. There was a column devoted to the explanation of the technique of animation and measurement. Essentially they used a TRIPLE buffered display of a two- bitplane screen with blue as the background color and three shades of gray to acheive the simulation of the white dots. From the picture in the article, the dots looked kinda like a flagelate protozoa. Anyhow the 68000 computed the next screen to be drawn and operated on the just released screen buffer. The blitter operated on the second buffer prior to display, and then the data was displayed. (Again I may have this mixed up a bit.) Those of us who are Amiga fans would appreciate the reasons for which the A1000 was chosen. 1) it has a flexible display/animation capability 2) A primitive form of parallel processing (68000,Blitter,Display) seemlessly allowed realtime adjustment of parameters governing the animation. As the subject's retina was stimulated with the blue light, they were asked to adjust a set of parameters which controlled the motion and speed of the animation. Once the animation was adjusted to look like what they saw, the values were recorded. Multiple trials were performed to yield an average set of parameters for each subject. They also performed a control experiment where they were asked to match one animation to another animation with known parameters. The control experiment provided the error margin. It is nice to see the Amiga being used in research for problems that just are not practical to attempt on the PC. I know there have been many times I wish that my lab had an Amiga controlling the equipment rather than a PC. -- Bill Murphy murphy@newton.physics.purdue.edu Enjoying my Amiga 2000, but holding out for a real computer: The Amiga 3000!!