[MAME]

Mahjong Dunhuang?
199?, unknown manufacturer

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

|---------------------------------------|
|uPD1242H  VOL     UM3567  AR17961  ROM6|
|          3.579545MHz                  |
|                  DSW1(8)          ROM5|
|   VOL            DSW2(8)              |
|                  DSW3(8)          ROM4|
|                  DSW4(8)              |
|                  DSW5(8)          ROM3|
|1   WF19054                            |
|8                                  ROM2|
|W                      |-------|       |
|A                      |       |       |
|Y                      |  *    |       |
|                       |       |       |
|                       |-------|       |
|                    12MHz         6264 |
|                                       |
|                                       |
|1         PAL                     6264 |
|0                                      |
|W                     Z80              |
|A  HM86171-80   BATTERY           6264 |
|Y                     PAL              |
|          PAL         PAL          ROM1|
|---------------------------------------|
Notes:
      Uses common 10-way/18-way Mahjong pinout
      Z80     - clock 6.000MHz [12/2]
      WF19054 - == AY3-8910. Clock = 1.500MHz [12/8]
      UM3567  - == YM2413. Clock 3.579545MHz
      HM86171 - Hualon Microelectronics HMC HM86171 VGA 256 colour RAMDAC (DIP28)
      6264    - UT6264PC-70LL 8k x8 SRAM (DIP28)
      *       - QFP120 IC marked 55102602-12. Logo on the chip is of two 5 1/4 inch floppy
                discs standing upright and next to each other, with the corner facing up,
                like 2 pyramids. The middle hole and head access slot are visible too.
                Chip was manufactured 50th week of 1993
      AR17961 - == Oki M6295 (QFP44). Clock = 1.500MHz [12/8]. pin 7 = high
      VSync   - 60Hz
      HSync   - 15.28kHz

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