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SEGA NAOMI I/O related questions

Posted: May 9th, 2017, 9:01 pm
by stmg
Hello, I'm waiting for my sega I/O board to come in, and from my understanding, it will require it's own separate PSU to operate. Now, the I/O board has it's own VGA port on it, and I've heard that the I/O board requires a sound amp for sound.

Would the I/O board cancel out the NAOMI's on-board VGA and sound?

Re: SEGA NAOMI I/O related questions

Posted: May 9th, 2017, 10:40 pm
by skate323k137
You don't necessarily have to run sound or video through the IO board. It depends on the cabinet you're using.

There is no problem taking VGA video / RCA audio straight from the NAOMI and skipping the IO board. To get sound / video through the IO board, you just run the NAOMIs AV into the IO board instead of straight to your display/speakers.

Re: SEGA NAOMI I/O related questions

Posted: May 22nd, 2017, 8:59 pm
by stmg
Thank you for the reply.

I have one more question.

I think I read somewhere that you can power the SEGA IO board from the 6 pin connector left of the black connector. Is this true? or do I have to use JAMMA to power the IO board?

Re: SEGA NAOMI I/O related questions

Posted: May 23rd, 2017, 12:01 am
by skate323k137
Are you talking about this IO board?

http://www.hklegend.com.hk/images/photos/22/9-b.jpg?13

If so, then I would think you could power it with the EXT power header instead of JAMMA, but I'm not 100% sure on the pinout. If you're not using that IO board can you let us know what one you are using? (part number or picture).

Re: SEGA NAOMI I/O related questions

Posted: May 23rd, 2017, 5:08 am
by stmg
skate323k137 wrote:Are you talking about this IO board?

http://www.hklegend.com.hk/images/photos/22/9-b.jpg?13

If so, then I would think you could power it with the EXT power header instead of JAMMA, but I'm not 100% sure on the pinout. If you're not using that IO board can you let us know what one you are using? (part number or picture).
I think that's the same connector on mine! its 6 pin correct? it is not labeled like EXT power on my device, it's the first SEGA IO board. My IO board actually came with this weird wire that connects to the EXT power, which then connects to this other odd board that came with it that plugs into the VGA port on the IO board, which the board just has another VGA connector on top of it, so I'm not sure what it does.

but if that's EXT power I do have a pinout of that. No idea what that board is though, if anyone wants pictures I'd be glad to take them

Re: SEGA NAOMI I/O related questions

Posted: May 23rd, 2017, 11:06 pm
by skate323k137
yes, please take a pic of your IO and any wiring if you could.

Re: SEGA NAOMI I/O related questions

Posted: May 25th, 2017, 9:31 pm
by stmg
skate323k137 wrote:yes, please take a pic of your IO and any wiring if you could.
http://i.imgur.com/OZaFZSo.jpg

This is my IO board along with the interesting board and cable it came with.

The 6 pin board is to the left of the black connector, but whatever this other board is plugs into that and uses that connection. I've never seen this cable nor board before... can I just power the board with wiring that 6 Pin connector to my power supply?

Re: SEGA NAOMI I/O related questions

Posted: May 25th, 2017, 11:40 pm
by dj_johnnyg
According to the Naomi Kit manuals, if you have power on the JAMMA connector, then don't apply power via the header. The manual states that you should only connect Switch, Switch Ground, Video and coin counters - although you can feed the video from the Naomi Mobo direct to your monitor if it has a DB-15 connector.

You are still going to need a 3.3V supply for the Naomi Mobo, the I/O just uses +5V and +12V.

I wouldn't connect power to the pin-header on that little board. I think this is probably a video-in port. The board looks to have 2 BD-15 ports (one input and one output) and the header will probably be to input a video signal from devices without a DB-15 connector (My impress had something similar, but without the DB-15 passthrough). Get a multi-meter and check for continuity against the header and the pins of the DB-15 connector, and I reckon they will have continuity. Check the connector nearest the header (the solder pins you can see) as I reckon the Caps will inhibit continuity at the other connector. I'm assuming the caps are some sort of smoothing or passive amplification like you got in RGB console cables.