Namco System 246 Disassembly

Namco System 246 B with JAMMA Adapter Board
Namco System 246 B with JAMMA Adapter Board

System 246 from Namco was introduced in 2001 along with its first game; Ridge Racer V. It is based on Sony PlayStation 2 hardware modified for arcade purposes.

Much like Sega did with the Naomi, the System 246 was widely licensed by Namco. Therefore there’s no exact specification for the System 246 as it was slightly modified for many of the games. Both Capcom and Taito released their own versions of the System 246. There’s four different revisions of System 246; A, B, C and a driving variant. Some games are very tightly coupled with a certain revision whereas other games work on two or all three and even the newer System 256. The 246 is capable of outputting both 31 kHz (VGA) and 15 kHz (CGA). Resolution, output level, sync frequency and sync signal are controlled via the DIP switches on the front of the unit.

Namco System 246 B Case
Namco System 246 B Case

The case fully disassembled. The motherboard slides in under the DVD shelf.

Namco System 246 B Motherboard (top)
Namco System 246 B Motherboard (top)
Namco System 246 B Motherboard (bottom)
Namco System 246 B Motherboard (bottom)

Top and bottom views of the 246 B motherboards (including the mounting plate). Didn’t take it apart further this time since the boards apparently had been recently cleaned. The battery needs a change from time to time.

Installing the motherboard in the case
Mounting the motherboard

The motherboard fits snugly under the DVD rig. Sliding it in place gave me a bit of headache. Took me a while to figure out that the guides got stuck on the case (the red circle). I needed to press the guides from below for it to slide all the way in.

Open Namco System 246 B Case
Everything in place

The inside of the case with everything in place, except for the DVD cover. As you can see the DVD player isn’t screwed to the case. It’s only kept in place by the rubber feet on all sides. Not sure if the case fan is original but sounds horrible and needs to go. It’s a standard 60 mm fan so there shouldn’t be any problems finding a quiet(er) replacement.

Connecting the 246 to your JAMMA cabinet

System 246 B JAMMA Adapter
System 246 B JAMMA Adapter

In order to connect the System 246 to a JAMMA cabinet you’ll need an adapter board. The most common being the one on the left.

The JAMMA connector serves buttons one through three. All other buttons can be found on the 10 pin AMP EI connector to the right. For fighting games you’d normally find the punch buttons on the JAMMA and the kick buttons on the AMP EI. Hence its commonly used name “kick harness”. Exactly which buttons are served on each connector differs between games. For instance, in Tekken 4 only two buttons (punch) are connected through the JAMMA and the other two through the kick harness (kick). But in Soul Calibur 2 all three buttons on the JAMMA are used (punch/kick) and only one button on the kick harness (guard).

10 pin AMP EI pinout
1 GND
2 NC
3 P1 Button 4
4 P1 Button 5
5 P1 Button 6
6 NC
7 P1 Button 4
8 P1 Button 5
9 P1 Button 6
10 GND

The 4 pin AMP EI connector is used for connecting the right speaker in stereo mode. The left speaker (or mono) is on the JAMMA.

4 pin AMP EI pinout
1 Not used
2 Not used
3 Right speaker (+)
4 Right speaker (-)

On the front of the case you find four DIP switches. They control game mode, output level of the video signal, sync frequency and sync signal.

DIP Switch Settings
ON OFF
1: Mode Test mode Game mode
2: Video signal output level
 – 31 kHz 0.7 V p-p 0.7 V p-p
 – 15 kHz 3.0 V p-p 0.7 V P-P
3: Monitor sync frequency 31 kHz 15 kHz
4: Video sync signal Composite sync Separate sync

Specifications

The hardware is based on Sony PlayStation 2 and as noted before the specs for the System 246 differs some due to modifications for specific games.

CPU – 128 bit “Emotion Engine”
System Clock 300 MHz
System Memory 32 MB
Memory Bus Bandwidth 3.2 GB per second
Co-CPU 1 (FPU)
Floating Point Performance 6.2 GFLOPS
Vector units 2 (VU0, VU1)
3D CG Geometric Transformation 66 million polygons per second
Image Decoder MPEG
GPU – “Graphics Synthesizer”
Clock Frequency 150 MHz
Memory Bus Bandwidth 48 GB per second
Memory Bus Width 256 bits
Maximum Polygon Rate 75 million polygons per second
Sound – SPU2 + CPU
Voices 48 channels on SPU2 (definable by software)
Sampling Frequency 44.1 kHz or 48 kHz
I/O
CPU Core Current PlayStation CPU
Clock Frequency 33.8 MHz or 37.5 MHz
Sub Bus Width 32 bits

Links

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4 thoughts on “Namco System 246 Disassembly

    1. That was my primary reason as well! At the moment I only have Tekken 4 but I’m expecting SCII from Japan any day now. Got hold of two Tekken 5 panels complete with card readers so I’ll be looking for a 256 and Tekken 5.1 too. Would love the T5 Dark Resurrection but that one needs an extra 256 unit for running the Live Monitor server 😦

  1. Hello Mister I have a system I changed 246 Time crisis3 dvd-rom after this system does not boot Please help me what should I do thank you in advance.

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