[MAME]

Mahjong Tian Jiang Shen Bing
IGS, 1997

This PCB is almost the same as IQBlock (IGS, 1996)
but the 8255 has been replaced with the IGS025 IC

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

IGS PCB N0- 0157-2
|---------------------------------------|
|uPD1242H     VOL    U3567   3.579545MHz|
|                         AR17961       |
|   HD64180RP8                   SPDT_SW|
|  16MHz                         BATTERY|
|                                       |
|                         S0703.U15     |
|                                       |
|J     |-------|          6264          |
|A     |       |                        |
|M     |IGS025 |          P0700.U16     |
|M     |       |                        |
|A     |-------|                        |
|                                       |
|                                       |
|                      |-------|        |
|                      |       |   PAL  |
|       A0701.U3       |IGS017 |        |
|                      |       |   PAL  |
|       TEXT.U6        |-------|        |
|            22MHz               61256  |
|                   DSW1  DSW2  DSW3    |
|---------------------------------------|
Notes:
      HD64180RP8 - Hitachi HD64180 CPU. Clocks 16MHz (pins 2 & 3), 8MHz (pin 64)
      61256   - 32k x8 SRAM (DIP28)
      6264    - 8k x8 SRAM (DIP28)
      IGS017  - Custom IGS IC (QFP208)
      IGS025  - Custom IGS IC (PLCC68)
      AR17961 - == Oki M6295 (QFP44). Clock 1.000MHz [16/16]. pin 7 = high
      U3567   - == YM2413. Clock 3.579545MHz
      VSync   - 60Hz
      HSync   - 15.30kHz

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