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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. |
5 | */ |
6 | #include "mapinc.h" |
7 | |
8 | #define cmd mapbyte1[0] |
9 | static DECLFW(Mapper189_write) |
10 | { |
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11 | //if(A>=0xc000) printf("$%04x:$%02x\n",A,V); |
12 | if((A&0xF100)==0x4100) ROM_BANK32(V>>4); |
13 | else if((A&0xF100)==0x6100) ROM_BANK32(V&3); |
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14 | else switch(A&0xE001) |
15 | { |
16 | case 0xa000:MIRROR_SET(V&1);break; |
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17 | case 0x8000:cmd=V;break; |
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18 | case 0x8001:switch(cmd&7) |
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19 | { |
20 | case 0:VROM_BANK2(0x0000,V>>1);break; |
21 | case 1:VROM_BANK2(0x0800,V>>1);break; |
22 | case 2:VROM_BANK1(0x1000,V);break; |
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23 | case 3:VROM_BANK1(0x1400,V);break; |
24 | case 4:VROM_BANK1(0x1800,V);break; |
25 | case 5:VROM_BANK1(0x1C00,V);break; |
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26 | } |
27 | case 0xc000:IRQLatch=V;break; |
28 | case 0xc001:IRQCount=IRQLatch;break; |
29 | case 0xe000:IRQa=0;X6502_IRQEnd(FCEU_IQEXT);break; |
30 | case 0xe001:IRQa=1;break; |
31 | break; |
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32 | |
33 | } |
34 | } |
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35 | void m189irq(void) |
36 | { |
37 | if(IRQa) |
38 | { |
39 | if(IRQCount) |
40 | { |
41 | IRQCount--; |
42 | if(!IRQCount) X6502_IRQBegin(FCEU_IQEXT); |
43 | } |
44 | } |
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45 | |
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46 | } |
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47 | void Mapper189_init(void) |
48 | { |
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49 | GameHBIRQHook=m189irq; |
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50 | SetWriteHandler(0x4120,0xFFFF,Mapper189_write); |
51 | SetReadHandler(0x6000,0x7FFF,0); |
52 | ROM_BANK32(0); |
53 | } |
54 | |
55 | |