Does a TBC (Timebase Corrector) cause video lag?

gdement · May 28, 2011

I was disappointed when I tried hooking my NES up to my PC video tuner. It's a fuzzy mess, it looks just like what happened to this guy on his SNES:

That isn't me, but my problem is the same with my NES.

According to the guy who responded to that video, supposedly the NES and SNES do this on purpose? What the hell.

Anyway, I used to think the problem was "dot crawl" caused by separating Y/C from the NES' composite video output. However, I recently realized that's not what it is - it appears to be a sort of horizontal timing error. From looking at a video capture from my NES, it's obvious that entire scanlines are getting randomly shifted by 1 pixel.

I recently lucked into an SVHS player with a TBC function. I tried recording the NES onto a VHS tape, then played it back. As soon as I enabled TBC - bingo - the fuzziness is gone. Unfortunately, the player's TBC function only works when playing from a tape, it can't be used as a passthrough.

So, I'm thinking that to play NES on my computer monitor, the solution might be to buy an old standalone TBC on ebay. Will this cause lag? I'm assuming it will lag the video by 1 frame. Is that correct, or is it worse/better than that?

amiman99 · June 5, 2011

I had a similar problem with Atari ST, Atari 130XE and others using external TV tuner. For some add reason the tuner would not sync properly and would display bad picture. When I run the video out from Atari to TBC and then to the TV tuner, the picture would get perfect. I did that few years ago, so I'm not sure if it will cause any lag.

I have couple internal TBCs on my Amiga 2000, so it is a little bulky. I need to come up with a cleaner solution.

I think you are on the right track.

On the other hand, you could try composite to VGA adapters if you have one of those NES that have composite out.

gdement · June 6, 2011

I had a similar problem with Atari ST, Atari 130XE and others using external TV tuner. For some add reason the tuner would not sync properly and would display bad picture. When I run the video out from Atari to TBC and then to the TV tuner, the picture would get perfect. I did that few years ago, so I'm not sure if it will cause any lag.

I have couple internal TBCs on my Amiga 2000, so it is a little bulky. I need to come up with a cleaner solution.

I think you are on the right track.

On the other hand, you could try composite to VGA adapters if you have one of those NES that have composite out.

Thanks for the input. I'll probably try a TBC once I get the funds to spend on it.

I used to have a composite->VGA adapter, but it died a few years ago. Overall, I think I prefer using the tuner, and a TBC might come in handy for other things as well.