[Dec/26/2003]

Skull Fang (Japan)
Data East, 1996

The game runs on Data East MLC hardware. 
The MLC system is basically an 8" x 6" x 2" plastic box with a JAMMA connector on it.
The PCB's are very compact and have almost entirely surface mounted components on both
sides of both boards. One board contains the RAM, sound hardware and I/O, the other 
board contains the CPU and ROMs. All main boards are identical between the MLC games and
can be changed just by plugging in another game and pressing test to reset the EEPROM defaults.
This game uses an encrypted CPU labelled 156, which is completely unknown. The encryption
is likely very complex because the files in the archive that are encrypted don't compress at all.
The decryption is internal to the chip which makes trojaning the board or manual decryption
very difficult.


PCB Layout
----------

Jamma Side:

DE-0444-1
|-----------------------------|
|                             |
| W24257            DE150     |
|   W24257                    |
|                             |
|J                      93C45 |
|A                            |
|M                            |
|M               DE223        |
|A                            |
|                             |
|                42MHz  W24257|
|                       W24257|
|                       W24257|
|            XILINK     W24257|
|5            XC3130          |
|0                            |
|P                            |
|I YMZ280B   YAC513           |
|N                            |
|-----------------------------|
Notes:
      - Yamaha YMZ280B clock: 14.000MHz (42 / 3)
      - DE150 custom (GFX controller)
      - DE223 custom (protection)
      - Xilinx XC3130 (TQFP100, Bus Controller?)
      - YAC513 D/A converter
      - 93C45 EEPROM, 128 bytes x 8 bit (equivalent to 93C46)
      - All SRAM is Winbond W24257S-70LL (32kx8)
      - 50 PIN connector looks like flat cable SCSI connector used on any regular PC SCSI controller card. It could
        be used for extra controls or maybe externally programming some IC's or factory diagnostic/repairs?
      - Bottom side of the JAMMA side contains nothing significant except a sound AMP, test SW, LED, some
        logic chips and connectors for joining the PCBs together.
      - Vsync: 58Hz


Game Side:

DE-0445-1 (top)
|-----------------------------|
|                             |
|                             |
|                             |
|  MCH-06             SH00-0  |
|                             |
|                     SH01-0  |
|                             |
|                             |
|                             |
|                             |
|                             |
| MCH-04    MCH-02    MCH-00  |
|                             |
|                             |
|                             |
| SH02-0                      |
|                             |
|                             |
|                             |
|-----------------------------|

DE-0445-1 (bottom)
|-----------------------------|
|                             |
|                             |
|                             |
|           DE156     MCH-07  |
|                             |
|                             |
|                             |
|                             |
|                             |
|                             |
|                             |
|                             |
|                             |
| MCH-01    MCH-03    MCH-05  |
|                             |
|                             |
|                             |
|                             |
|                             |
|-----------------------------|

Notes:
      - DE156 clock: 7.000MHz (42MHz / 6, QFP100, clock measured on pin 90)
      - All ROMs SH* are 4M x 16bit EPROMS (27C4096)
      - All MCH* ROMs are surface mounted 16M SOP44 MASK ROMs 

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