GD-ROM spine labels

I got a request for a post on the spine labels I’ve done for my NAOMI GD-ROM’s. Never really thought anyone would be interested in them but wrong I was 😛


I use a Brother QL-570 label printer and design the labels in Brother’s P-touch Editor. It’s got an express mode and a pro mode. For doing your own designs Pro mode is preferred. The GD-ROM spine measures 184 mm x 12 mm (H x W). Even though there is a 12 mm wide roll I use a 29 mm wide roll for printing the GD-ROM spine labels. The reason being that the QL-570 wants a bit of margins on all sides. For this reason I’ve also made the label 187 mm long.

GD-ROM spine labelResources

Here are a few image files for getting started. I’ve picked them all from the Intertubes and I don’t make any claims as to owning any of these.

And here’s my label design in case you want to use it 🙂

Naomi Spine Label

Sega Chihiro

Sega Chihiro unit

The Sega Chihiro was introduced in 2003. It is based on an early version of Microsoft’s Xbox console.

Sega Chihiro with GD-ROM drive
Sega Chihiro with GD-ROM drive

The Chihiro uses an nVidia MCPX2 instead of the MCPX3 found on the Xbox. It also has 128 MB (the Xbox has 64 MB) memory and an LCP connector directly on the board. Instead of a DVD drive, the Chihiro (like the Naomi and the Triforce) uses Sega’s own GD-ROM drive. Games can also be loaded from a network server. The games are stored in RAM on the media board (DIMM board).

There’s two versions of the Chihiro; Type 1 and Type 3. The main difference being Type 3 having the media board integrated whereas Type 1 uses a regular DIMM board like the Naomi.

Even though the list of Chihiro games is quite short it boasts a number of popular titles like Outrun 2, Ghost Squad, Virtua Cop 3 and Crazy Taxi High Roller. There’s also a number of Chihiro Satellite Terminal games that are widely spread in Asia but never really found their way to the rest of the world; the MJ (mahjong), Sangokushi Taisen and Sega Golf Club franchises to mention a few. The satellite terminal games use regular Chihiro units linked together over a LAN connection.

Japanese players getting instructions on how to play Sangokushi Taisen 3 (
Japanese players getting instructions on how to play Sangokushi Taisen 3 (

The Chihiro Type 3 consists of two units. The lower unit contains the Xbox and system boards and the upper contains the media, network and security key boards and a battery for keeping the loaded game in memory when the system is turned off.

Top Unit

Sega Chihiro top unitIn the upper unit of the Chihiro we find the media board (bottom) and the network board (top). The media board holds the RAM modules; either 512 MB or 1 GB. Most games are available in two versions. One for 512 MB units and one with (usually) higher definition graphics for 1 GB units.

The RAM on the media board is not directly accessible from the Xbox board. It acts like a solid state drive for storing the game data after it has been loaded from the GD-ROM drive or a network server. The Xbox board accesses the media board like an IDE drive. This serves three purposes:

  • After the game data is loaded the GD-ROM can power down and hence will not wear out as fast as otherwise. The game stays in memory for up to 72 hours while powered off.
  • Faster boot up time once the game data is loaded.
  • Enables netbooting. Without storing the game data on the media board the Chihiro would have to constantly read from a game server. While possible the system would have to have been adapted to this. With the media (DIMM) board the hardware/technology  was already in place.

The small vertical board to the right is for the security key and to the lower left you can spot the battery.

The Chihiro won’t operate without a battery installed. The battery is needed for holding the game in memory during reboots and while the system is turned off.

Jumpers on the media board.On the media board you find a set of jumpers. The ones you have to pay attention to are jumpers 5, 8, 9, and 10. Jumper 5 controls the amount of RAM used and should match the amount of memory installed. Jumpers 8 – 10 switches between GD-ROM and network boot.

Jumper Settings
Jumper 1 – 2 2 – 3
5 1 GB (two DIMM modules) 512 MB (one DIMM module)
8 Always on 2 – 3
9 GD-ROM Network
10 Always on 1 – 2

Bottom Unit

Opened Chihiro system revealing the bottom unit.Lifting off the top unit reveals the system board. The battery on the system board is for keeping system settings and needs to be changed every now and then. It’s a normal 3V CR2032 button cell.

Removing the system board takes several steps:

  1. Remove the filter board. Unscrew the five remaining screws and carefully push the board out.
  2. Loosen the two bolts by the VGA connector. In fact it’s advisable to remove the plate around the VGA and USB connectors entirely.
  3. Disconnect the three power cables on the side of the board.
  4. Sega Chihiro system boardUnscrew the five screws that keep the board in place.
  5. Push the holder (upper right corner of the board in the picture above) aside to release the board.
  6. Gently lift up the board and disconnect the four cables connecting the system board to the Xbox board.

Lifting up the system board reveals the Xbox main board at the bottom. The main thing you have to observe on the Xbox board are the electrolyte capacitors. They are prone to leaking (bad/cheap components) and if they do they might corrode and damage the Xbox board beyond repair.

Sega Chihiro - Xbox boardThere’s at least two different versions of the Xbox board; one with three capacitors next to the GPU and one with five. The board in the picture is the three cap version and as you can see they have started to leak and need to be replaced.

Test Drive

Testing the Sega Chihiro units.

I had two units over for check up and testing. Since all Chihiro games require special type controls (steering wheels, guns etc) and most of them won’t even boot up on anything but JVS hardware and I only have a JAMMA cabinet it took a little trial and error until I found out Ghost Squad version: A indeed boots fine without it’s gun controls or a JVS I/O card.

Sega Chihiro running Ghost Squad

On the filter board there is a green and a red status LED. Only the green should be on for normal operation. If they both blink something’s wrong with the unit.

Sega Chihiro filter board.

Thank you for reading. Hope you enjoyed the post. Let me know what you think.



Naomi Motherboard

Sega NAOMI logoThis is the first in a series of articles about the Sega NAOMI system. Later posts will cover the hardware (I just love taking things apart :P), connecting the NAOMI to JAMMA cabinets, setting up the NAOMI with a GD-ROM and netbooting (loading games from a server).

The Sega NAOMI (New Arcade Operation Machine Idea), first shown at JAMMA in September 1998, is the successor to the Sega Model 3 platform.

Sega Naomi System

It’s based on the same hardware components as the Dreamcast game console. Though the NAOMI has twice the amount of system memory and video memory and four times as much sound memory as the Dreamcast. Multiple units can be linked to improve graphics performance or to support multiple monitors. The NAOMI Universal Cabinet was developed specifically for the NAOMI system and can house up to 16 units.


Sega Naomi GD-ROM reader

Another key difference between the NAOMI and the Dreamcast is how the game media is handled. The Dreamcast streams the data from the GD-ROM while the NAOMI arcade boards features 168 MB of solid state ROM or GD-ROM’s using a DIMM board and a GD-ROM reader. The contents of the disc is downloaded onto the DIMM board’s RAM on start up. Once the disc has been read the game is run from the RAM for better performance and reducing the mechanical wear on the GD-ROM reader.

Even if the system is turned off the game will load from the RAM when powered on again. Only if the game data in the RAM gets corrupted of if the system’s been powered off for about 72 hours the game will again have to be read from the GD-ROM.


Unlike Sega’s previous arcade platforms the NAOMI was widely licensed for use by other game publishers. Besides Sega about 20 companies has produced titles for the NAOMI system including Capcom, Namco Bandai, Tecmo, Cave, Sammy, SNK, Jaleco and Koei.

Taito launched their G-Net system (based on Sony’s PlayStation hardware) the same year as the NAOMI and, as Sega, tried to license it widely to developers. While the NAOMI became a huge success the G-Net never really made it and only some 20+ titles were ever released for the G-Net.

Connecting the NAOMI to JAMMA

Capcom I/O AdapterThe NAOMI uses the newer JAMMA Video Standard (JVS) for I/O. The JVS uses a USB A port for inputs and VGA for video output. The NAOMI is able to output graphics in VGA and CGA resolutions. There are three different I/O boards available for interfacing the NAOMI with JAMMA setups. Two were manufactured by Sega and another from Capcom.

The Capcom JVS/JAMMA converter is preferable since it offers a voltage converter for the needed 3.3 V line, and audio amplifier with volume control, the JAMMA connector and a JAMMA+ kick harness compatible with CPS2 and CPS3 games.


  • The Atomiswave system from Sammy is based on NAOMI hardware.
  • Theoritically a 16 board NAOMI system could do (16 x 3.5 mpps) = 56 million polygons/second. In reality it won’t manage more than around 20 to 30 mpps.
  • Naomi is a Japanese female name that translates to “above all beauty”.

System Specifications

CPU Hitachi SH-4 32-bit RISC CPU (200 MHz 360 MIPS / 1.4 GFLOPS)
Graphic Engine PowerVR 2 (PVR2DC)
Sound Engine ARM7 Yamaha AICA 45 MHZ (with internal 32-bit RISC CPU, 64 channel ADPCM)
Main Memory 32 MByte
Graphic Memory 16 MByte
Sound Memory 8 MByte
Media ROM Board (maximum size of 172MBytes) / GD-Rom
Simultaneous Number of Colors Approx. 16,770,000 (24bits)
Polygons 2.5 Million polys/sec
Rendering Speed 500 M pixel/sec
Additional Features Bump Mapping, Fog, Alpha-Bending (transparency), Mip Mapping (polygon-texture auto switch), Tri-Linear Filtering, Anti-Aliasing, Environment Mapping, and Specular Effect.

Game List

Game lists for the NAOMI system are available at

More info

Pac Man – Bargain or Trash?

Midway Pac Man PCBI managed to win a Pac Man / Ms. Pac Man game board for less than $40 including shipping over at eBay a week or so back. Looked legit and in good shape. So the question is: was it a bargain or have I ended up with a pile of trash?

Since I was passing Chicago earlier this week I had the board together with some other games delivered there for saving on the shipping. So on Wednesday I finally got the chance to examine my possible bargain and except for the desperate need of cleaning and perhaps a cap change it looks fine. It’s missing the cable for connecting the Ms. Pac Man daughter board but that one’s quite easy to find so I’m optimistic. But I won’t know for sure until I get back home again in a couple of weeks. Oh, and I’ll need a JAMMA adapter too since the board comes with the old Midway interface.

Gundam DX vs Zeon GD-ROM with manual and artworkThe other two packages waiting for me was Gundam DX vs. Zeon GD-ROM for the Naomi and Soul Calibur II Ver. A and D for System 246.

Guilty Gear XX and new NAOMI stash

May from Guilty Gear
May from Guilty Gear

Being a sucker for the character design of the Guilty Gear series – especially May (still suck at playing the game though) I ended up with a Sega NAOMI setup with GD-ROM reader through Johans auctions over at a couple of weeks back.

Still missing a JVS to JAMMA adapter and some power cables I haven’t had the chance to try them out yet. So I spent my time gathering some intel and writing a couple of pages on the stash I got in the deal.

The Stash

  • Sega NAOMI System
  • Sega NAOMI GD-ROM reader, DIMM board and SCSI cable
  • Capcom vs. SNK Millennium Fight 2000 Pro
  • Guilty Gear XX #Reload

I’ll get back regarding the games as soon as I’m able to try them out. Meanwhile I put together a couple of pages about the NAOMI System and the GD-ROM.

Sega NAOMI Stash
Sega NAOMI Stash

There’s plenty of guides on the Interwebs on how to setup the NAOMI with the GD-ROM. The trickiest part being if you like me miss some of the cables and need to find replacements. Since the NAOMI uses the newer JVS standard for I/O you’re gonna need an adapter for hooking it up in a JAMMA cabinet. The best option being Capcom’s JVS to JAMMA converter <- I need one of those.