HDMI-NES? - NESdev BBS

HDMI-NES?
by oRBIT2002 on 2009-10-12 (#51333)

I'm not that much into hardware, but I am just curious, would it be possible to mod a NES to have a HDMI output?
Last time I tried connecting a NES to my LCD (using SCART), all I got was a bouncing image. I think the low resolution was the problem...

by hyarion on 2009-10-13 (#51339)

You would need to rebuild most of the system, create a new PPU for video and a new CPU if you want digital audio, so it wouldn't be much NES left...

Try another cable, you should be able to get a stable image on a LCD using SCART.

Re: HDMI-NES?
by tepples on 2009-10-13 (#51342)

oRBIT2002 wrote:
I'm not that much into hardware, but I am just curious, would it be possible to mod a NES to have a HDMI output?
Last time I tried connecting a NES to my LCD (using SCART), all I got was a bouncing image. I think the low resolution was the problem...

NES, Mega Drive, Super NES, and the vast majority of PlayStation and Nintendo 64 games use a 240p variant of NTSC or a 288p variant of PAL. These look fine on CRT SDTVs, but HDTVs with more complicated upscalers designed only for 480i might choke. Because no spec adopted by a national TV regulator describes the progressive variants of SDTV, no TV is required to implement them. The upscaler engineers probably assume that only a statistically insignificant fraction of HDTV buyers held on to their pre-Dreamcast consoles.

If the picture is bouncing by half a scanline, up and down at 30 Hz, that's normal on some upscalers. But if the picture is bouncing by more than that, you'll need to use an external upscaler. I have a Philips DVD recorder whose upscaler turns the NES's 240p video into 480i NTSC and 720p HDMI signals that does this for me.

by rbudrick on 2009-11-04 (#52097)

By any chance would the above describe why my RGB-modded NES will not work on LCD HD TVs? Seems to work fine on plasmas or anything else.

-Rob

by tepples on 2009-11-05 (#52133)

Does it fail on LCDs and plasmas of the same brand (e.g. Sony vs. Sony)? Do you know which upscaler chips these LCDs and plasmas use?

by NESHomebrew on 2009-11-06 (#52210)

I have a 42" LG and it works fine. I was disappointed that the light guns don't work...

by Jarhmander on 2009-11-07 (#52298)

Prolly because there's too much delay between the game state and the screen. In other words, the fact that there's a little delay for displaying those white boxes can mess all the game logic.

by Memblers on 2009-11-07 (#52302)

~J-@D!~ wrote:
Prolly because there's too much delay between the game state and the screen. In other words, the fact that there's a little delay for displaying those white boxes can mess all the game logic.

Actually I believe it relies on the horizontal refresh rate of the TV. I'm pretty sure you have to manually poll the zapper on every hit-able scanline as it's being drawn. It's actually quite precise on a single frame, vertically. The boxes are for determining horizontal position. I'm no CRT expert, but I've played around with the zapper before.

by rbudrick on 2009-11-08 (#52341)

tepples wrote:
Does it fail on LCDs and plasmas of the same brand (e.g. Sony vs. Sony)? Do you know which upscaler chips these LCDs and plasmas use?

Dunno about what chips it uses, but it is a 46" Vizio. Would Sony matter? I heard rumors Sony actually makes the Vizio brand, but I have no clue. It doesn't fail on plasmas.Every thousandth time or so I test it it will give an image, but it wouldn't refresh past the first frame (title screen) and sometimes if it did even a little bit, you could see ghosting of sprites behind the background...kind of like those images in scary movies of something trying to push through a wall that's really made of latex.

-Rob