Posted by Druin on 27, 2000 at 8:41 PM:
In Reply to: Re: Extra adapter for rotary games not using dial inputs posted by Bill Lash on 27, 2000 at 6:32 PM:
: Interesting. Looking at your other rotary interface, it seems to be 12 positions per revolution, while this one is 8 positions per revolution. Will this cause anyone any problems? You will get a full circle with only 3/4 of a revoluton of the joystick.
Although it seems at a glance that the 12 joystick inputs are a few too many and some activity would go unnoticed, that's not the case. There could be only 3, or 300 actual inputs from the joystick within that circle and all it would really mean is that you have to turn it more times to complete a circle, obviously, but as far as operation goes, it's completely irrelevant. All that's important isn't how many inputs there are, but rather, which direction along those inputs you are actually going. All the circuits care about is whether you're going from position number 7 to position 8, or position 7 to position 6 (clockwise or counter clockwise). Likewise, if there were 300 inputs, it would only care if you're going from number 250 to 251, or 249 (clockwise or counter clockwise again). So nothing is problematic.
I'm currently right now building the above adapter circuit on the breadboard and verifying my theoretical design, and I did find some hardware glitches, and resolved them so far. I updated the schematic, so the one on my site, as well as the one linked to the original message of this thread, are also automatically updated via the URL going to the single GIF file on my site. As of right now I've tested it out up to the part just before the diodes. I might find some more bugs in the diode network but I got the counter chip and 4 to 16 decoder chips both running smoothly. All info will be on the site for when it's fully tested and verified for people to build if they want.