[MAME]

 Konami System GX
 
 Basic hardware consists of:
 - MC68EC020 main CPU at 24 MHz
 - MC68000 sound CPU with 2x K054539 PCM chips plus a TMS57002 DASP for effects
 
 Tilemaps are handled by the old familiar K054156 with a new partner K056832.
 This combination is mostly compatible with the 156/157 combo but now sports
 up to 8 bits per pixel as well as larger 128x64 tile planes.
 
 Sprites are handled by a K053246 combined with a K055673.  This combo was
 actually used on some 16 bit Konami games as well.  It appears identical
 to the standard 246/247 combo except with 5-8 bits per pixel.
 
 Video output is handled by a K055555 mixer/priority encoder.  This is a much
 more capable beast than the earlier 53251, supporting a background gradient
 and flexible priority handling among other features.  It's combined with the
 54338 alpha blending engine first seen in Xexex for flexible blending.
 
 There are actually 4 types of System GX hardware, which are differentiated
 by their ROM board.  The most common is the "Type 2".
 
 68020 memory map for Type 2:
 000000: BIOS ROM (128k)
 200000: game program ROM (1 meg, possibly up to 2)
 400000: data ROMs
 c00000: Work RAM (128k)
 cc0000: Protection chip
 d00000: 054157 ROM readback for memory test
 d20000: sprite RAM (4k)
 d40000: 054157/056832 tilemap generator    (VACSET)
 d44000: tile bank selectors		          (VSCCS)
 d48000: 053246/055673 sprite generator     (OBJSET1)
 d4a000: more readback for sprite generator (OBJSET2)
 d4c000: CCU1 registers                     (CCUS1)
 00: HCH			  6M/288   8M/384   12M/576	       224 256
 02: HCL		   HCH 	    01      01        02	  VCH  01  01
 04: HFPH		   HCL      7f      ff        ff	  VCL  07  20
 06: HFPL		   HFPH	    00      00        00	  VFP  11  0c
 08: HBPH		   HFPL	    10      19        23	  VBP  0e  0e
 0A: HBPL		   HBPH	    00      00        00	  VSW  07  05
 10: VCH		   HBPL	    30      3f        4d
 12: VCL		   HSW	    03      04        09
 14: VFP
 16: VBP
 18: VSW/HSW
 1A: INT TIME
 1C: INT1ACK (read VCTH) INT1 = V blank
 1E: INT2ACK (read VCTL) INT2 = H blank
 d4e000: CCU2 registers		    (CCUS2)
 d50000: K055555 8-bit-per-pixel priority encoder (PCUCS)
 d52000: shared RAM with audio 68000      (SOUNDCS)
 d56000: EEPROM comms, bit 7 is watchdog, bit 5 is frame?? (WRPOR1)
 d56001: IRQ acknowledge (bits 0->3 = irq 1->4), IRQ enable in hi nibble (bits 4->7 = irq 1->4)
 d58000: control register (OBJCHA, 68000 enable/disable, probably more) (WRPOR2)
 d5a000: dipswitch bank 1		    (RDPORT1)
 d5a001: dipswitch bank 2
 d5a002: input port (service switch)
 d5a003: EEPROM data/ready in bit 0
 d5c000: player 1 inputs		    (RDPORT2)
 d5c001: player 2 inputs
 d5e000: test switch			    (RDPORT3)
 d80000: K054338 alpha blender registers
 d90000: palette RAM for tilemaps
 da0000: tilemap RAM (8k window, bankswitched by d40033)
 dc0000: LANCRAMCS
 dd0000: LANCIOCS
 dd2000: RS232C-1
 dd4000: RS232C-2
 dd6000: trackball 1
 dd8000: trackball 2
 dda000: ADC-WRPORT
 ddc000: ADC-RDPORT
 dde000: EXT-WRPORT
 de0000: EXT_RDPORT
 e00000: type3/4: PSAC2 registers
 e20000: type3/4: unk. register
 e40000: type3/4: unk. register
 e60000: type3/4: PSAC2 linecontrol RAM
 e80000: type3/4: main monitor's palette
 ea0000: type3/4: sub monitor's palette
 ec0000: type3/4: frame flag
 f00000: 32k of RnG2 additional RAM
 
 IRQs:
 1: VBL (at 60 Hz)
 2: HBL
 3: Sprite DMA complete
 4: from protection device, indicates command completion for "ESC" chip

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