Using an ATX PC PSU for Naomi

[OldFoo]

Sega Naomi hardware requires 3 specific voltages in order to power up correctly, they are +5v , +12v and 3.3v



there are 3 ways to supply the Naomi 1 & 2 motherboards with the voltages they require

1\ a suitable JAMMA > JVS I/O board like the Capcom I/O or the Sega V2 I/O. both of these take the 12v and 5v lines from your regular JAMMA PSU and converts one of the voltages to output at 3.3 aswell as the 5v & 12v from your JAMMA PSU.

2\ Sega Naomi PSU - as found in the Naomi Universal cabinets

3\ a regular ATX PSU



to use a PC PSU you need to identify the voltages needed.

we are looking for +5v, +12v and 3.3v

the pinout for ATX PSU's can be found here

http://pinouts.ru/data/atxpower_pinout.shtml



once these have been identified we then need to know the pinout for the 8 pin and 6 pin connectors on the Naomi motherboard

the pinout can be found here

http://webgb.hp.infoseek.co.jp/gtech/connect.html



although they aren't strictly required, it is also advised that you obtain the correct JST connectors as required by the Naomi motherboards



heres my Naomi PSU adaptor to allow use of a PC PSU







and heres it plugged in to a Shuttle PSU





the 2 pin header is for an on/off switch, just a switch between pin 14 and a ground as you need to short pin 14 to enable the PSU to power up, you can simply just make a wire bridge between a ground and pin 14, I personally use a simple switch.

[OldFoo]

Mr-Megalo,



I like the way you explain with lots of detail, how to set your power for the SEGA NAOMI using a PC PSU. But is there anyone you know that will do this for you if you pay for it to be done? If you do know someone who?

Like I said on the old forum I am new to this forum and new to the SEGA NAOMI. I am a big fan of the SEGA Dreamcast. I will now like to start with the SEGA NAOMI, and I will need help so sorry if my questions are stupid at time (But like I said I am new to all of this).



naomi_fan

:smt002

[OldFoo]

I would be happy to do this as i can get the connectors fairly easily, but shipping fom Australia would be a bit of a deal killer.

[OldFoo]

I would be happy to do this as i can get the connectors fairly easily, but shipping fom Australia would be a bit of a deal killer.

Berty,



Thanks for the offer but if shipping is more then what the job is worth then NO it will not be worth it. But thank you anyways Berty.



THANKS

naomi_fan

:smt002

[OldFoo]

Hi,



When a person is using a SEGA i/o (With no power & audio inputs) on a Mass Systems Super Nova, does a person need a PSU? Or will the Mass Systems Super Nova power up the NAOMI board? Can a person buy a SEGA PSU (Not a PC PSU). And if you can, where can you find a SEGA PSU? Is there any PC PSU that you can use on the NAOMI, with out having to rewire it (Like you have to on the ATX PSU)? If so witch one is it (What brand and name)?



THANKS

naomi_fan

:smt120

[OldFoo]

Short answers...



The supernova wont power the naomi unless you are using a capcom io, and even then it may not have enough juice to do so. Only the second generation Sega IO will convert +5 to 3.3 for the naomi and these are as rare as rockinghorse poo.



The naomi requires 3.3V which a standard arcade psu doesnt have.



Any PC PSU that you get will need to be wired to suit the naomi's inputs.



Suzo may sell the Sun brand PSU for naomi, but thats all i know on that subject.



On a personal note, its really not that big of a deal to re-wire a pc psu using the correct connectors. Im fairly new to all of this but when i made my first psu, it was alot easier than i thought.

[OldFoo]

Berty,



Thank you for all your help and info. I will try to see if I can buy a PSU from someone, but if not I will need to try to come up with a PSU myself. What type of outputs suit the NAOMI's inputs?



THANKS

naomi_fan

:smt023

Short answers...



The supernova wont power the naomi unless you are using a capcom io, and even then it may not have enough juice to do so. Only the second generation Sega IO will convert +5 to 3.3 for the naomi and these are as rare as rockinghorse poo.



The naomi requires 3.3V which a standard arcade psu doesnt have.



Any PC PSU that you get will need to be wired to suit the naomi's inputs.



Suzo may sell the Sun brand PSU for naomi, but thats all i know on that subject.



On a personal note, its really not that big of a deal to re-wire a pc psu using the correct connectors. Im fairly new to all of this but when i made my first psu, it was alot easier than i thought.

[OldFoo]

I could probably knock-up a connector similar to the one Mr-Megalo has.



All you would need to do is plug your ATX PC supply into the ATX end, and plug the 2 Naomi connecstors into the Motherboard.



Shipping shouldn't be too much, and I have all the bits to hand.



May try making one for myself...



Downside would be that voltages couldn't be altered.



Let me know...



John

[OldFoo]

Berty,



What type of outputs suit the NAOMI's inputs?

Do you mean the connectors? They are a square "molex" style connector. If you are talking power, then +3.3, +5 & +12 Volts. The ATX PSU should supply enough current (Ampage) to run the system.

[OldFoo]