Namco System 246/256

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Namco System 246/256
Manufacturer Namco/Sony
Year 2001
Media CD-ROM, DVD-ROM, Hard Drive, 8MB Security Dongle, 8MB Memory Card
CPU 128 Bit Emotion Engine
GPU Graphics Synthesizer operating at 150 MHz
Sound SPU2+CPU
Resolution 15k / 31k
Wiring Standard JVS
Predecessor Namco System 10
Successor Namco System 357

The Namco System 246/256 is an arcade platform based on the Sony PlayStation 2. Sometimes referred to as Namco 2x6, as the two hardwares are very similar and run much of the same software.

The system is comprised of a motherboard and optical or hard disk drive, housed in a large metal case. Software is booted from a security dongle and runs either straight off supplied optical media (DVD-ROM or CD-ROM), or a hard drive.The security dongle is cosmetically and electrically identical to a PS2 memory card, but contains different security algorithms to prevent unauthorized copying. There are no regional restrictions inherent to any dongle, media, or chassis, but many games were released with limited export regulations in the form of licensing or legal text at boot.


There are 5 known major revisions of the System 2x6 hardware. These are as follows:


  • System 246(Driving) chassis
    246(Driving) The very first of the System 246 chassis is easily identified by its large size, but lack of JAMMA interface. It appears to have been subject to a very limited release, having only beed verified to have been released with Ridge Racer V: Arcade Battle. Wangan Midnight R may also have been released on this chassis variant, but there is no evidence to back up this claim yet. Mainboard is Sony model COH-H30000, based around a modified PlayStation 2 motherboard. The Namco daughterboard is the first generation System246 MOTHER PCB, providing AV and JVS, but an internal I/O board is also included in the case, FCA PCB, connected to the JVS port via a loopback cable. This is designed to connect externally to the STR PCB interface board. The Namco daughterboard also has an unused ROM socket, and two RAM sockets, however, only one is used in any production system, populated with a RAM32 PCB (32MB DRAM).
  • System 246A gun chassis
    246 Rev.A The first official "main" 246 chassis type features a large silver enclosure with onboard JAMMA interface perpendicular to the front of the chassis. It is known to have been bundled with Vampire Night and Bloody Roar 3 (which received a custom red enclosure variant), among others. This and the Driving chassis share the same main board, and the Namco daughterboard is similar, but now supports a more traditional AV and JVS configuration, with an additional System246 JAMMA PCB connected to an onboard header. Gun game variant bundles ship without the JAMMA I/O and a plate covering it.
  • System 246B chassis
    246 Rev.B The second main 246 chassis type features the new standards as seen in the rest of the chassis series, and is the most popular outside of Japan, having been featured in a bundles with Tekken 4, Soul Calibur II, Time Crisis 3, and others. It is designed as a universal PCB, regardless of I/O or cabinet type (L+B, Gun, Driving, Touchscreen), and offers a ribbon cable input on the side of the chassis for connecting the updated System246 JAMMA(B) PCB as an optional external interface for JAMMA cabinets. Mainboard is Sony Model COH-H31100, although one extremely rare variant is known to exist which uses a COH-H30000. The Namco Daughterboard is updated to Namco System246 PMOTHER PCB, and no longer features removable RAM or ROM options, opting instead for a fixed amount of onboard RAM.
  • System 246C chassis
    246 Rev.C The most unique revision to the 246 featured externally a smaller shell, but internally, a unified motherboard and daughterboard as a single PCB. This version of the 246 appears to have been most common in Japan, where the market received many games on the 246 platform that were not localized for use in the rest of the world. An (optional) opening in the case is available for installing a System246 UE PCB internally (previous models can support the PCB externally) to provide ethernet based networking. Normal and lead-free (Pb-Free) solder versions of the motherboard exist, and are marked as such for regulatory compliance. All system capability is identical to the previous models, including support for the ATAPI command modes that are explicitly used on some games (i.e. Tekken 4).
  • System 256 chassis
    (shown here with hard drive)
    256 The final chassis revision has the least variants, but offers some of the most capability. This chassis was rarely seen outside of Japan (except in Tekken 5 and Time Crisis 4 systems which require a 256 to function), and has a number of changes to the unified PCB model of the 246, most notably, the addition of a custom expansion bus used by only two known boards (EX CARD PCB and EX SOUND PCB), and a compatibility jumper. The System 256 PCB no longer supports the ATAPI commands required for running early CD/DVD System 246 games, opting for a compatibility mode known as 246+ that supports all other known games. This mode is selected by way of a "246+/256" mode jumper found inside the case near the external ribbon cable port. The PlayStation 2 controller ports have been removed in order to make the case shorter, and a even smaller case variant is known to exist, designed for Time Crisis 4 that has no optical drive, and only an internal hard drive mount point. A new expansion port has been added to allow the connection of PlayStation 2 controllers via an cabled adapter. A black enclosure variant appears to exist, although it is unknown if this is for a specific game bundle.

Security Dongle

The Sony model

COH-H10020 and USA packaging

COH-H10020 security dongle is at the core of the 2X6 game boot process. The COH-H3XXXX main board, when initialized, searches for a MagicGate encrypted boot file in the contents of the PlayStation 2 memory card filesystem on the COH dongle in slot 1 (left). The system proceeds to boot this code identically to a retail PlayStation 2. Any files required to access external media (optical drive, hard drive, etc) will be present here, but additional libraries or game code can be loaded from the media once it has been initialized and is accessible to the COH board. No known algorithm or security code for accessing the contents of the COH dongle through the memory card interface is known to exist at present, and a retail PlayStation 2 or PlayStation 3 (with memory card adapter) cannot access the card. There is no capability to access the data on the card from a retail PlayStation 2, and conversely, there is also no capability to accidentally (or intentionally) erase or reformat the card as the security mechanisms embedded in the COH dongle magic gate chip are not openable by any retail hardware. This includes the MagicGate encryption keys [extracted from the PlayStation 3 firmware]. Inspection of the contents of the dongle's flash memory must be done via manual extraction of the data directly from the 8MB NAND flash chip. While COH dongles can be read and written by COH board, very few (if any) production games leverage the ability to write to the dongles, instead opting to use the onboard battery-backed ram on the COH board to store game settings, highscores, and the like.

In addition to the capability to access memory card form factor COH series dongles, the 2X6 can also read and write to conventional retail Sony PlayStation 2 Memory cards for storing larger amounts of information, for example Soul Calibur 2's campaign mode.

Optical Drive

In the majority of cases, System 246 uses CD-ROM or DVD-ROM discs as its primary storage. The hardware accesses the DVD drive for data not contained on the game dongle, for example, 3d models, levels, cinematics, music, etc., and uses the 32MB RAM cache to store data loaded from the drive to reduce stress on the optical drive and discs after the data is loaded. There are no protection mechanisms surrounding the discs and a simple duplication of the disc onto recordable media was actually suggested and commonplace for operators suffering from read problems in their drives, or scratched discs. A number of different model CD/DVD drives are known to have shipped with 2X6 systems, but many do not support certain ATAPI commands used in older Namco titles, preventing these games from properly loading or completing an attract cycle. Off-the-shelf PC drives can serve as replacements, as the game will not boot without a valid sony COH series dongle and signed executable code. A list of some working drive replacements is shown below:

Manufacturer Model Status
Hitachi / LG H-L Data Storage LG GSA-4164B Super Multi DVD Drive (09-2005) Working
Hitachi / LG H-L Data Storage LG GSA-4082B Super Multi DVD Drive (02-2004) Working
Hitachi / LG H-L Data Storage LG GCC-4120B CD-RW/DVD-ROM Drive (04-2002) Working
NEC DV-5800C DVD-ROM Drive (02-2004) Working
Samsung SD-616 DVD-ROM Drive (12-2001) (Factory Supplied) Working
Samsung SD-M1802 Factory
Samsung SD-816 Factory
Sony DW-U10A (05-2003) Factory
Toshiba SD-M1612 DVD-ROM Drive (01-2003) Factory
  • Non of the drives mentioned above are still available from retailers.

Hard Drive

Some games utilize a 3.5" hard drive in place of an optical drive to speed up access to data that is too large to be cached in the 32MB buffer RAM. The format of the drive and its data is completely up to the discretion of the game developer, and examples have been seen in both raw and Sony APA partition schemes. As is the case with the optical drive, the data on the drive cannot be accessed unless the game executable contains the libraries necessary for accessing the data and the partition types used, so a hard drive cannot be used as a replacement for an DVD-ROM game or vice versa at the discretion of the user. There are no security measures or serial number checks performed on the drive for any known games, so a simple DD block-level copy to a new ATA drive of sufficient dimensions will suffice. Again, as with optical media, it is customary to find operator cloned media in the used market for drives replaced due to fatigue. Generally, most factory drives will have a sticker with the game code and serial number on the actual drive, but Taito hard drive games notoriously have their part number sticker on the mounting bracket, not the drive.

I/O Boards

The Namco 2x6 is a fully-JVS compliant system, and offers both a traditional JVS I/O port and (on 246B and later), a Namco proprietary ribbon cable interface designed to connect to the System246(B) JAMMA PCB.

  • System246 JAMMA PCB This I/O board is only used on the 246A chassis, as it is installed internally, and connects directly to a socket on the Namco Daughterboard. Its capabilities are identical to its updated external version.
  • System246(B) JAMMA PCB The default I/O board supplied with most 246B and later chassis, and also available as an add-on kit, contains an onboard stereo amp, video sync inverters to convert the malformed PlayStation 2 sync signal, a JAMMA pinout, and a 10-pin kick harness to support up to 6 buttons per player.
  • Namco FCA PCB is Factory installed inside the System 246(Driving) chassis, but also makes an appearance on Cobra as an interface to the card reader.
  • Namco V185 I/O PCB is a JVS I/O board common on most 2X6 series gun games such as Vampire Night, Cobra, and Time Crisis 3 and Time Crisis 4.
  • Namco V257 STR PCB is a PCB that can be connected to the 246(Driving) chassis via its proprietary front cable port to provide normal driving game and force-feedback functionality. Game that supper this PCB may verify that the force feedback motor is powered by performing a power-on test that checks the wheel potentiometer value while turing the wheel via force feedback. If this check fails, the game may not boot (for example Ridge Racer V: Arcade Battle).
  • Namco V290 FCB PCB is a JVS I/O board required for Touchscreen games on the 2X6 platform such as Dragon Chronicle Online, Druaga Online, The iDOLM@STER, Whole Brain, and others. It supports serial touchscreen interface, card readers, and limited button I/O.
  • Namco V329 NA-JV PCB is a JVS I/O board that is also used on some 2X6 series gun games, and appears mostly interchangeable with the V185 I/O PCB depending on cabinet fittings.
  • Taito Driving I/O is an unknown model (Please update) PCB required for Taito's Battle Gear 3 and Battle Gear 3: Tuned games, providing driving interface and custom card reader functionality for the "key" cards as required by the games.
  • Namco Cyber Lead Arcade Cabinet feature an LED display that, when connected to a 2X6 game that supports them, will display game-specific graphics and information. If a game does not support it, it will show the default display modes.
  • Other Many other JVS I/O pcb from various manufacturers have been tested to work flawlessly for general lever and button games, for example Sega 837-13551-92, 837-13844-02 and 838-13683-02, and the Capcom JVS I/O, with analog inputs and pass-through JVS mode supported on a per-game basis.

Kick Harness

The kick harness available on both variants of the System 246 JAMMA PCB is a 10 pin JST connector located on the front right of the PCB.

The pinout is as follows:
1. GND
2. NC
3. P1 Button 4
4. P1 Button 5
5. P1 Button 6
6. NC
7. P2 Button 4
8. P2 Button 5
9. P2 Button 6
10. GND

System 256 PlayStation Controller Interface

The System 256 chassis is missing the PlayStation 2 controller ports, and in its is a n expansion header.
Pinout is as follows (Pins on JST plug are in odd/even rows, not sequential.):
1. DAT (P1 Pin 1)
2. CMD (P1 Pin 2)
3. ATT (P1 Pin 6)
4. NC
5. CLK (P1 Pin 7)
6. UNKNOWN (P1 Pin 8)
7. ACK (P1 Pin 9)
8. DAT (P2 Pin 1)
9. CMD (P2 Pin 2)
10. ATT (P2 Pin 6)
11. GND (P1/2 Pin 4)
12. CLK (P2 Pin 7)
13. UNKNOWN (P2 Pin 8)
14. ACK (P2 Pin 9)
15. NC
16. VCC (P1/2 Pin 5)

Stereo Audio

The JAMMA audio pins on both variants of the System 246 JAMMA PCB offer mono sound when connected in a cab using a traditional JAMMA harness, but stereo sound is also available via a 4 pin JST connector located on the front right of the PCB.

The pinout is as follows:
1. Left +
2. Left -
3. Right +
4. Right -


Maintained 246/256 Software List Source


The Namco System 256 was discontinued in Fall 2010 after the release of the final game on the platform, Taiko Drum Master 14. The successor to the 256, the Namco System 357, is based on the [Sony PlayStation 3] platform, but does not have any compatibility with 2X6 games via adapter or otherwise, however the Konami Python utilizes the same Sony COH series mainboard as the 246, including limited basic boot (no production game) compatibility, yet interfaces with arcade hardware via different hardware and support libraries.