Hey guys, I recently found one of those YENO SC-3000, which is like the SEGA except it outputs RGB at 50Hz. I did some homework and found out the culprit was the TMS9929ANL, which outputs component (converted to RGB by a daughter board) at 50Hz. It exists a TMS9928ANL, which is exactly the same excepts it outputs at 60Hz. Now, I have the console, the replacement chip, but I'm not sure if straight replacing the chip would simply work, and I would love your input. Specifically I don't know if I have to deal with crystal oscillators: there is only one on the board, and it's a 10.73863 KDS. For reference, 60Hz modding an SMS2 is as easy as grounding a pin from the PPU. https://en.wikipedia.org/wiki/Texas_Instruments_TMS9918 http://www.cs.columbia.edu/~sedwards/papers/TMS9918.pdf (pinout page 54) I mean, it seems straightforward, but I don't want to make a stupid mistake and I'd rather have you guys check on what I'm doing.
That xtal is almost exactly 3 times the NTSC color burst frequency, so it would seem that it's the right value for a 60Hz system - note that it's actually the wrong value for PAL, which is probably why there is no composite 60Hz version of that VDP.
Turns out, there was a second crystal that I didn't spot. This one is 3.58G CMT and is only on PAL systems apparently. However, simply replacing the chip seems to have worked. I now have the gameplay at the correct speed, but the screen is displaying the wrong colours. But it could very well be an unrelated problem though, which is going in its own thread now.
Hi, did you fix colour issue? I wasn't sure if your other posts were for this issue or not (dropped RGB line). Cheers!
There is a pot that changes the color balance (and brightness?) on the RGB board. I was able to get better colours that way, to how they were before, I got confused comparing an emulator on an LCD to the output of a real console on a CRT TV. Display calibration can go a long way.
