1 /* Is this an MMC3 workalike piece of hardware, with the addition of
2 a register at $4120 or does it have only partial MMC3 functionality?
3 A good test would be to see if commands 6 and 7 can change PRG banks
4 and of course test the regs >=$c000, on the real cart.
8 #define cmd mapbyte1[0]
9 static DECLFW(Mapper189_write)
11 if(A==0x4120) ROM_BANK32(V>>4);
14 case 0xa000:MIRROR_SET(V&1);break;
15 case 0x8000:cmd=V;break;
16 case 0x8001:switch(cmd&7)
18 case 0:VROM_BANK2(0x0000,V>>1);break;
19 case 1:VROM_BANK2(0x0800,V>>1);break;
20 case 2:VROM_BANK1(0x1000,V);break;
21 case 3:VROM_BANK1(0x1400,V);break;
22 case 4:VROM_BANK1(0x1800,V);break;
23 case 5:VROM_BANK1(0x1C00,V);break;
30 void Mapper189_init(void)
32 SetWriteHandler(0x4120,0xFFFF,Mapper189_write);
33 SetReadHandler(0x6000,0x7FFF,0);