knudsen@ihnss.UUCP (08/29/83)
Thanks for the complete review of the new Radio Shack mouse. It's nice to know some of that new '84 catalog stuff has already made it to some Radio Shack stores. I hate to say it, but you were right--the limited 64x64 resolution of the mouse is an internal restriction of the Coco, not the mouse. The Coco is one of very computers with a true analog joystick interface, and actually uses successive-approximation A/D conversion to read the stick values, which are just voltages between 0 and +5 V. (The standard Shack sticks are just pots inside). Unfortunately, the Coco's A/D conversion (and D/A, great for speech and music) only goes to SIX BITS accuracy -- hence 64 positions, period. SO--if you have an Apple (8-bits, more or less, using a timer I believe) or some other analog-digital interface, the Radio Shack Mouse is essentially unlimited in precision. Hope it doesn't develop wear problems like the joysticks. BTW, I wrote a software solution for my Coco's limited resolution-- it works like the old rotary UHF TV tuners did before they acquired click stops. You move a "coarse" window around and then "fine tune" your position within it by reversing direction. Any takers? mike k