[MAME]


4 En Raya (IDSA 1990)


RAM :
	1 x GM76c28-10 (6116) RAM
	3 x 2114  - VRAM (only 10 bits are used )

ROM:
  27256 + 27128 for code/data
  3x2764 for gfx

PROM:
 82S123 32x8
 Used for system control
 	(d0 - connected to ROM5 /CS , d1 - ROM4 /CS, d2 - RAM /CS , d3 - to some logic(gfx control), and Z80 WAIT )

Memory Map :
  0x0000 - 0xbfff - ROM
  0xc000 - 0xcfff - RAM
  0xd000 - 0xdfff - VRAM mirrored write,
  		tilemap offset = address & 0x3ff
  		tile number =  bits 0-7 = data, bits 8,9  = address bits 10,11

Video :
	No scrolling , no sprites.
	32x32 Tilemap stored in VRAM (10 bits/tile (tile numebr 0-1023))

	3 gfx ROMS
	ROM1 - R component (ROM ->(parallel in) shift register 74166 (serial out) -> jamma output
	ROM2 - B component
	ROM3 - G component

	Default MAME color palette is used

Sound :
 AY 3 8910

 sound_control :

  bit 0 - BC1
  bit 1 - BC2
  bit 2 - BDIR

  bits 3-7 - not connected

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