Sega-Naomi

Can anyone explain to me why the Naomi VGA output won't work with an LCD television's PC input? I've tried 2 different motherboards and 2 separate TVs and... nothing. I have a test pattern generator that I set to 640x480 resolution color bars, and it shows up fine. Obviously it can display VGA resolution. So what's the deal?





Thanks,

ask andy he had it on his plasma i think

It displays 640x480 at 31khz. Check to make sure that your tv can handle display at this resolution and frequency.

Flazh wrote:It displays 640x480 at 31khz. Check to make sure that your tv can handle display at this resolution and frequency.

Of course it does--that's why the test pattern generator worked.

Does that test pattern run at that frequency though? As you can obviously have it running at a much higher frequency, but the same resolution.

We have two hi-def LCD TVs at home. It won't work with the larger one at all (out of range, if I remember right). It does work with the smaller one, but it cuts off some of the top and bottom (yes, the TV is set to 4:3 with no zoom).

A good dedicated computer monitor is the only way to go, in my opinion. Although I can't find an LCD monitor bigger than 21 inches that isn't widescreen for my homemade cabinet plans.

Flazh wrote:Does that test pattern run at that frequency though? As you can obviously have it running at a much higher frequency, but the same resolution.

Yeah, it runs at 31kHz. The TV says invalid source when I plug in the Naomi. I used to have the Naomi hooked up to a 19" LCD computer monitor, and it would have problems with that as well. I had to use the test pattern generator to get it to recognize a signal, and then use a switcher to switch over to the Naomi. Even that won't work with the TV. There's definitely something abnormal about the Naomi's video signal. It works fine in my low-res cab, but that's set up for vertical at the moment and I want to be able to play Guilty Gear. (And "yes" the dip switches are set properly for each.)

This may be related to the jumper settings on the Naomi motherboard. I remember a time when I had 2 Naomi 1 systems that reacted differently on the same LCD screen. I then made sure both systems had the same jumper settings and the problem was gone.



For whatever reason, the jumper settings are not referenced in any system manual. But I can gather that some of those jumpers have to do with how the screen resolution is handled. Sorry I don't have more jumper informaton, it's just not available. :smt009

joshua3dg wrote:This may be related to the jumper settings on the Naomi motherboard. I remember a time when I had 2 Naomi 1 systems that reacted differently on the same LCD screen. I then made sure both systems had the same jumper settings and the problem was gone.



For whatever reason, the jumper settings are not referenced in any system manual. But I can gather that some of those jumpers have to do with how the screen resolution is handled. Sorry I don't have more jumper informaton, it's just not available. :smt009

You're referring to jumpers, not dip switches, right?

That's correct. The jumpers on the PCB, not the front switches. :smt045