I've always wanted to know it...
How the Gun on Duck Hunt worked
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Juan F. Ramirez
- Bugaboo
- Posts: 5148
- Joined: Tue Nov 14, 2017 6:55 am
- Location: Málaga, Spain
Re: How the Gun on Duck Hunt worked
Nintendo brought out a new version of the game for the Virtual Console on the Wii U that allowed you to play it on a modern television, using a Wii Remote and sensor bar to do the aiming.
Except that now you can't get that version any more because they closed the eShop, and the world is once more bereft of a classic.
Except that now you can't get that version any more because they closed the eShop, and the world is once more bereft of a classic.
Re: How the Gun on Duck Hunt worked
On the old Grandstand TV console there was a single target white dot on a green background, and the gun just detected the brightness of the spot. You could actually turn the brightness of the TV up such that the green was bright enough to trigger the sensor, so you couldn't miss! You could also shoot the ball in a game of Tennis and it would turn invisible for a few seconds.
As this video says, the NES one worked by flashing up a frame of the TV where only the target area was in white on a black background, which the gun could detect. And through timing, it could work out roughly which row of the TV screen it had triggered off. So it could tell targets apart vertically.
I suspect the same was true of the Speccy lightgun bundled in 128K boxes, but I never had one or tried it. I also had an ST one which was much more accurate. I seem to remember the C64 originally had a lightpen port which could do pixel-perfect tracking through similar technology. I once saw someone using a lightpen on a Commodore Plus/4 - the art package put up a small white square which tracked the tip of the lightpen, but you had to move it slowly, as it would lose track if you moved it too fast for the white square to keep up.
On the Playstation, with the G-Con, it flashed up an all-white screen and the timing was good enough to calculate horizontal position on the screen, not just vertical. The calibration screen was light yellow and you could see it tracking with near pixel-perfect accuracy.
But with each stage of evolution, you don't just need faster processing, you need a sensor that responds faster, to the change in light levels, to be able to detect the exact moment the TV raster passes.
Of course, none of this works anymore with LCD TVs. The Wii used a 'sensor bar', which isn't a sensor at all; it's two IR LEDs a fixed distance apart. There's actually a camera in the tip of the remote that tracks the two lights to work out where it's pointing. Sony instead went with cameras on top of your TV tracking glowing coloured balls on the tips of the controllers to work out their position, then accelerometers in the controllers for orientation. Nothing to do with the TV at all.
As this video says, the NES one worked by flashing up a frame of the TV where only the target area was in white on a black background, which the gun could detect. And through timing, it could work out roughly which row of the TV screen it had triggered off. So it could tell targets apart vertically.
I suspect the same was true of the Speccy lightgun bundled in 128K boxes, but I never had one or tried it. I also had an ST one which was much more accurate. I seem to remember the C64 originally had a lightpen port which could do pixel-perfect tracking through similar technology. I once saw someone using a lightpen on a Commodore Plus/4 - the art package put up a small white square which tracked the tip of the lightpen, but you had to move it slowly, as it would lose track if you moved it too fast for the white square to keep up.
On the Playstation, with the G-Con, it flashed up an all-white screen and the timing was good enough to calculate horizontal position on the screen, not just vertical. The calibration screen was light yellow and you could see it tracking with near pixel-perfect accuracy.
But with each stage of evolution, you don't just need faster processing, you need a sensor that responds faster, to the change in light levels, to be able to detect the exact moment the TV raster passes.
Of course, none of this works anymore with LCD TVs. The Wii used a 'sensor bar', which isn't a sensor at all; it's two IR LEDs a fixed distance apart. There's actually a camera in the tip of the remote that tracks the two lights to work out where it's pointing. Sony instead went with cameras on top of your TV tracking glowing coloured balls on the tips of the controllers to work out their position, then accelerometers in the controllers for orientation. Nothing to do with the TV at all.