1 /* FCEUmm - NES/Famicom Emulator
2  *
3  * Copyright notice for this file:
4  * Copyright (C) 2020 negativeExponent
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version 2
9  * of the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
19  */
20 
21 /* NES 2.0 Mapper 380 denotes the 970630C circuit board,
22  * used on a 512 KiB multicart having 42 to 80,000 listed NROM and UNROM games. */
23 
24 #include "mapinc.h"
25 
26 static uint16 latche;
27 static uint8 dipswitch;
28 
29 static SFORMAT StateRegs[] = {
30    { &latche, 2 | FCEUSTATE_RLSB, "LATC" },
31    { &dipswitch, 1, "DPSW" },
32    { 0 }
33 };
34 
Sync(void)35 static void Sync(void)
36 {
37    if (latche & 0x200)
38    {
39       if (latche & 1) /* NROM 128 */
40       {
41          setprg16(0x8000, latche >> 2);
42          setprg16(0xC000, latche >> 2);
43       }
44       else /* NROM-256 */
45          setprg32(0x8000, latche >> 3);
46    }
47    else /* UxROM */
48    {
49       setprg16(0x8000, latche >> 2);
50       setprg16(0xC000, (latche >> 2) | 7);
51    }
52    setmirror(((latche >> 1) & 1) ^ 1);
53 }
54 
DECLFR(M380Read)55 static DECLFR(M380Read)
56 {
57    if (latche & 0x100)
58       return dipswitch;
59    return CartBR(A);
60 }
61 
DECLFW(M380Write)62 static DECLFW(M380Write)
63 {
64    latche = A;
65    Sync();
66 }
67 
M380Reset(void)68 static void M380Reset(void)
69 {
70    dipswitch = (dipswitch + 1) & 0xF;
71    latche = 0;
72    Sync();
73 }
74 
M380Power(void)75 static void M380Power(void)
76 {
77    dipswitch = 0;
78    latche = 0;
79    Sync();
80    setchr8(0);
81    SetReadHandler(0x8000, 0xFFFF, M380Read);
82    SetWriteHandler(0x8000, 0xFFFF, M380Write);
83 }
84 
StateRestore(int version)85 static void StateRestore(int version)
86 {
87    Sync();
88 }
89 
Mapper380_Init(CartInfo * info)90 void Mapper380_Init(CartInfo *info)
91 {
92    info->Power = M380Power;
93    info->Reset = M380Reset;
94    GameStateRestore = StateRestore;
95    AddExState(&StateRegs, ~0, 0, 0);
96 }
97