ta0

I looked at the output of an LCD for both Gyromite and Duck Hunter. The output frames are actually the correct ones. My guess is that R.O.B. is not recognizing the codes because there is no "return to zero" : between two consecutive green frames there is no black sync line like there is for the CRT. Perhaps if somebody used a 3D-capable TV with alternating frames at 120 Hz, connected the game to the left eye channel and nothing to the right eye, it might make it recognizable to R.O.B. Making the zapper work will be more difficult as it seems to be very sensitive to the delay in the loop.

I got a Rob and Gyromite. I used a high speed camera (480 fps or 8x the TV rate) to look at the actual output from the TV. I got the same codes as Tursi. The instructions are given one per frame, at 60 fps. There is no black frame after outputing the instruction. The test sequence that flashes the LED on the head is: 00000 000101 1101011 11111. I would think that having the correct timing is pretty important (although I would guess that R.O.B. still works with 50Hz TV systems from other countries). I think the problem with a digital TV, even if it has a 60 Hz refresh rate, is that it may think that consecutive analog frames are interlaced and tries to de-interlace them, what mixes 0 and 1 frames. By the way, I also looked at Duck Hunt: when you press the trigger you get a black frame, next one that has only a white square on the duck, next back to the normal display. If you have two ducks: black frame, frame with white square for the first duck, frame with white square for the second duck, again frame with white square for the second duck, resume normal display. Interestingly, if I route the TV signal through a VCR, the increased delay is enough to stop the gun from detecting the ducks.