Sega Nomad Help Please

[The Jackal]

New member mikeyp needs your assistance, guys:


I've just got a SEGA nomad, done a couple of mods to it already, eg. Battery mod and the start/A button region mod.

I would like to change the screen, would be too easy to simply attach it to composite. I have bought a redguard et-350 screen. Looking into the pinouts for the video chip on the controller board, I was wondering about whether it would be possible to connect it to the s-video mod.

A PDF of the datasheet is here http://www.dz863.com/datasheet-83767...r-With-Slicer/ or direct link here http://www.dz863.com/downloadpdf-vdn...ovd-TW9910.pdf

If I do the s-video mod, but instead of installing a 4 pin plug, connect it to pins 13 and 15................

Is there anything else I need to do? I'm aware I probably need to do something with the caps linking unconnected inputs to ground but so far I'm not sure on the specifics.

Thanks for your help in advance. I'll follow up with photographs of the controller board if needed.

[Moirai]

Why not use RGB?

[mikeyp]

Thank you The Jackal, I do appreciate it.

Why not use RGB?

Not sure the decoder chip supports it, hence why I thought of using s-video. If it does then yes RGB would be ideal....

[TmEE]

Nomads got CXA1645 which have already amped Y and C pins available, you only need serios capacitors and maybe 56...86 chm resistors if the image is too bright.
But S-video will not work out of box, that chip like many others has i2c interface that is controlled by a small µCU that sets brightness, contrast and other parameters including what video input is used upon power on...

[mikeyp]

Huh.... so I'd have to use one of the existing inputs in combination with CIN but that's no guarantee that CIN wouldn't be disabled. I guess that's why no one has attempted this. Knowing this I'm undecided whether it's worth trying.

Thoughts?

[TmEE]

Ihe default is only Cvideo, no S-video. I have tried...

[mikeyp]

Ah, ok thank you. It was a nice thought while it lasted though. Different screen required to pursue this one then.

[lumclaw]

Unfortunately we don't have a source of suitable RGB replacement screens. Factory Nomads use it, why the Sega screen doesn't need a color fix for PAL games.

[Moirai]

Unfortunately we don't have a source of suitable RGB replacement screens. Factory Nomads use it, why the Sega screen doesn't need a color fix for PAL games.

That sucks, no way to mod the screen to accept RGB, either?

[TmEE]

Only option is to program a nem µCU that sets up the screen in a different manner. It is something I plan to do sometime (not this year)