NAOMI Question.

I was looking at some pictures of the Namoi cart setup and on the back next to the two RCA audio plugs there's what I assume is the video out, it looks awfully 'VGA' like, anyone know what this outputs specifically? Is it converted before it hits the monitor?

Naomi using a standard DB15 pin connector, just like PC videocards, and the output is VGA 640x480 @ 31.5khz at 0.7vpp (exactly the same as VGA), there is a dipswitch which can be changed, I think its dipswitch 4, that when on outputs at 320x240 at 15.75khz (Standard Res, please not the RGB voltage is still 0.7vpp, Jamma boards are around 4.0vpp, so the colours will look washed out and faded, however the Capcom Jamma convertor has a video amp on board).

"Naomi using a standard DB15 pin connector, just like PC videocards, and the output is VGA 640x480 @ 31.5khz at 0.7vpp (exactly the same as VGA)"

So (sorry if the question is stupid) would it be possible to use the Naomi board in a standar PC VGA monitor?

Yep, you can use Naomi on PC monitors, the "proper" Naomi cab uses a 29" 31.5khz monitor, and is pretty cool for wathing DVDs on via the PC..


My Vaps listing:
<a href="http://www.vaps.org/members/gbr/andrew.lewis5@ntlworld.com.html" target="_blank">http://www.vaps.org/members/gbr/andrew.lewis5@ntlworld.com.html</a>

This is what I know about the Naomi setup. Since I have no first-hand experience with it I may well be wrong on many points, so Andy (or others) please confirm or correct what I say.A full Naomi system (but with no GD-ROM drive) should look like
this:
<a href="http://www.system16.com/sega/boards/naomihook.jpg" target="_blank">http://www.system16.com/sega/boards/naomihook.jpg</a> (please copy&paste the links)
This is a Naomi 1 motherboard. AFAIK, you can install a GD-ROM drive on a Naomi 1 but only if the boot ROM version is recent enough (you can read what boot ROM version it is on some EPROM sticker inside the board), otherwise the older EPROM must be replaced with a newer one.This is the connector side or filter board, as it’s actually called:
<a href="http://www.system16.com/sega/boards/naomiplug.jpg" target="_blank">http://www.system16.com/sega/boards/naomiplug.jpg</a>
You can't use a standard arcade PSU (+/-5v, +12V, GND) because a Naomi also needs +3.3v. The PSU
plugs into the two female molex connectors to the right (the white ones). At their left we find the 15pin VGA connector and the RCA jacks. If you install a Naomi setup in a cabinet, you’ll need a sound amp board, which should be the board next to the PSU in the first picture above. Of course you can also use your stereo for that purpose, inwhich case you won’t need the amp PCB. The two black things near the jacks are optic fiber connectors to have more Naomi’s communicating together (with some games). In the upper left part we have (starting from the left): test and service buttons, DIP switch bank and a USB port. DIP no. 1 sets the screen resolution (15KHz or 31KHz). The USB port is used to connect the Naomi motherboard to the I/O (Input/Output) board which is where your Jamma harness plugs in. The power pins on the jamma connector of the I/O board willremain unused, I guess. However, judging from the picture it seems to me that the I/O board does get power from the PSU (via a molex connector). If you don’t want to use the RCA jacks I assume you can get sound from the I/O board Jamma pins but it will probably be mono (again, I guess). Likewise, it seems to me that if you don’t want to use the VGA connector on the
Naomi motherboard, you may get the video outputs from the I/O board just as well.The black thing with a white sticker in the first pic above looks like an isolation transformer to me and seems to be connected to the sound board, so this needs to be supplied with AC? (I don’t know). But if you’re using a stereo as well as a PC monitor you won’t need any of these...

Now to the GD-ROM.
<a href="http://www.system16.com/sega/boards/naomi2hardblue.jpg" target="_blank">http://www.system16.com/sega/boards/naomi2hardblue.jpg</a>
It looks like it’s secured to the motherboard with some screws (and/or a mounting plate, I don’t
know). I think its only connection with the motherboard is through the DIMM board (via an
external cable). The DIMM board is that part on the top of the motherboard that looks like a normal Naomi cart, but contains RAM instead of ROM. Along with the software (the GD-ROM disk) you get a key chip that must beinserted somewhere inside the DIMM board. Also, the DIMM is equipped with a battery that progressively reduces its maximum charge any time the game is connected/disconnected. I wonder what kind of battery it is: a common one or a Naomi-specific one?

According to a source "the GD Rom system has a
very clever way of getting around the loading delay time. When the game is initially installed, the GD ROM loads its content into the Naomi RAM. Once this is completed, the GD ROM goes into standby unless the RAM gets corrupted or the game gets shut off for 72 hours or more. This does two things:

1) Eliminates loading delays completely, (after initial power up.)
2) Minimizes the on/off cycles of the GD ROM drive and greatly increasing the life of thismechanical device."

So if I understand correctly, once the game has
first been installed (read: disk content loaded into DIMM board), you can turn the power off and on again and the game will be ready to go (read: no loading time whatever), but if it remains shut off for 72 hrs or more, you’ll have to reload the disk data into the DIMM board again. And so on.

[ June 11, 2002: Message edited by: MKL ]</p>