[MAME]

	Midway MCR-68k system


	Games supported:
		* Zwackery (Chip Squeak Deluxe)
		* Xenopohobe (Sounds Good)
		* Spy Hunter 2 (Sounds Good/Turbo Chip Squeak)
		* Blasted (Sounds Good)
		* Arch Rivals
		* Tri-Sports
		* Pigskin 621AD


	Memory map

****************************************************************************

	========================================================================
	CPU #1
	========================================================================
	000000-03FFFF   R     xxxxxxxx xxxxxxxx    Program ROM
	060000-063FFF   R/W   xxxxxxxx xxxxxxxx    Program RAM
	070000-070FFF   R/W   xxxxxxxx xxxxxxxx    Background video RAM
	071000-071FFF   R/W   xxxxxxxx xxxxxxxx    Additional RAM
	080000-080FFF   R/W   xxxxxxxx xxxxxxxx    Sprite RAM
	090000-0900FF     W   xxxxxxxx xxxxxxxx    Palette RAM
	0A0000-0A000F   R/W   xxxxxxxx --------    M6840 I/O
	0B0000-0B0001     W   -------- --------    Watchdog
	0C0000-0C0001     W   -------- xxxxxxxx    Sound I/O
	0D0000-0D0001   R     xxxxxxxx xxxxxxxx    External inputs
	0E0000-0E0001   R     xxxxxxxx xxxxxxxx    External inputs
	0F0000-0F0001   R     xxxxxxxx xxxxxxxx    External inputs
	========================================================================
	Interrupts:
		NMI ???
		INT generated by CTC
	========================================================================
	NOTE: Pigskin and Tri-Sports have similar memory maps; the addresses
			are simply shuffled around
	========================================================================

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