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/* FCE Ultra - NES/Famicom Emulator | ||
* | ||
* Copyright notice for this file: | ||
* Copyright (C) 2023 | ||
* | ||
* This program is free software; you can redistribute it and/or modify | ||
* it under the terms of the GNU General Public License as published by | ||
* the Free Software Foundation; either version 2 of the License, or | ||
* (at your option) any later version. | ||
* | ||
* This program is distributed in the hope that it will be useful, | ||
* but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
* GNU General Public License for more details. | ||
* | ||
* You should have received a copy of the GNU General Public License | ||
* along with this program; if not, write to the Free Software | ||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
*/ | ||
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/* NES 2.0 Mapper 448 | ||
* VRC4-based 830768C multicart circuit board used by a Super 6-in-1 multicart. | ||
*/ | ||
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#include "mapinc.h" | ||
#include "latch.h" | ||
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static uint8 reg; | ||
static uint8 vrc4Prg; | ||
static uint8 vrc4Mirr; | ||
static uint8 vrc4Misc; | ||
static uint8 vrc4IRQLatch; | ||
static uint8 vrc4IRQa; | ||
static uint8 vrc4IRQCount; | ||
static int16 vrc4IRQCycles; | ||
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static SFORMAT StateRegs[] = { | ||
{ ®, 1, "REGS" }, | ||
{ &vrc4Prg, 1, "PREG" }, | ||
{ &vrc4Mirr, 1, "V4MI" }, | ||
{ &vrc4Misc, 1, "V4MS" }, | ||
{ &vrc4IRQLatch, 1, "VILA" }, | ||
{ &vrc4IRQa, 1, "VIMO" }, | ||
{ &vrc4IRQCount, 1, "VICO" }, | ||
{ &vrc4IRQCycles, 2, "VICY" }, | ||
{ 0 }, | ||
}; | ||
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static void Sync(void) { | ||
setchr8(0); | ||
if (reg & 0x08) { /* AOROM */ | ||
setprg32(0x8000, ((reg << 2) & ~0x07) | (latch.data & 0x07)); | ||
setmirror(MI_0 + ((latch.data >> 4) & 0x01)); | ||
} else { | ||
if (reg & 0x04) { /* UOROM */ | ||
setprg16(0x8000, ((reg << 3) & ~0x0F) | (vrc4Prg & 0x0F)); | ||
setprg16(0xC000, ((reg << 3) & ~0x0F) | 0x0F); | ||
} else { /* UNROM */ | ||
setprg16(0x8000, (reg << 3) | (vrc4Prg & 0x07)); | ||
setprg16(0xC000, (reg << 3) | 0x07); | ||
} | ||
switch (vrc4Mirr & 0x03) { | ||
case 0: setmirror(MI_V); break; | ||
case 1: setmirror(MI_H); break; | ||
case 2: setmirror(MI_0); break; | ||
case 3: setmirror(MI_1); break; | ||
} | ||
} | ||
} | ||
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static DECLFW(writeVRC4) { | ||
if (A < 0x9000) { | ||
vrc4Prg = V; | ||
Sync(); | ||
} else { | ||
switch (A & 0xF000 | ((A >> 2) & 3)) { | ||
case 0x9000: | ||
vrc4Mirr = V; | ||
Sync(); | ||
break; | ||
case 0x9002: | ||
vrc4Misc = V; | ||
break; | ||
case 0xF000: | ||
vrc4IRQLatch = (vrc4IRQLatch & 0xF0) | (V & 0x0F); | ||
break; | ||
case 0xF001: | ||
vrc4IRQLatch = (vrc4IRQLatch & 0x0F) | (V << 4); | ||
break; | ||
case 0xF002: | ||
vrc4IRQa = V; | ||
if (vrc4IRQa & 0x02) { | ||
vrc4IRQCount = vrc4IRQLatch; | ||
vrc4IRQCycles = 341; | ||
} | ||
X6502_IRQEnd(FCEU_IQEXT); | ||
break; | ||
case 0xF003: | ||
vrc4IRQa = (vrc4IRQa & ~0x02) | ((vrc4IRQa << 1) & 0x02); | ||
X6502_IRQEnd(FCEU_IQEXT); | ||
break; | ||
} | ||
} | ||
} | ||
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static DECLFW(M448WriteReg) { | ||
if (vrc4Misc & 1) { | ||
reg = A & 0xFF; | ||
Sync(); | ||
} | ||
} | ||
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static DECLFW(M448Write) { | ||
LatchWrite(A, V); | ||
writeVRC4(A, V); | ||
} | ||
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static void FP_FASTAPASS(1) M448CPUHook(int a) { | ||
int count = a; | ||
while (count--) { | ||
if ((vrc4IRQa & 0x02) && ((vrc4IRQa & 0x04) || ((vrc4IRQCycles -= 3) <= 0))) { | ||
if (~vrc4IRQa & 0x04) { | ||
vrc4IRQCycles += 341; | ||
} | ||
if (!++vrc4IRQCount) { | ||
vrc4IRQCount = vrc4IRQLatch; | ||
X6502_IRQBegin(FCEU_IQEXT); | ||
} | ||
} | ||
} | ||
} | ||
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static void M448Reset(void) { | ||
reg = 0; | ||
Sync(); | ||
} | ||
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static void M448Power(void) { | ||
reg = 0; | ||
vrc4Prg = 0; | ||
vrc4Mirr = vrc4Misc = 0; | ||
vrc4IRQLatch = vrc4IRQa = vrc4IRQCount = vrc4IRQCycles = 0; | ||
LatchPower(); | ||
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SetReadHandler(0x8000, 0xFFFF, CartBR); | ||
SetWriteHandler(0x6000, 0x7FFF, M448WriteReg); | ||
SetWriteHandler(0x8000, 0xFFFF, M448Write); | ||
} | ||
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static void StateRestore(int version) { | ||
Sync(); | ||
} | ||
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void Mapper448_Init(CartInfo *info) { | ||
Latch_Init(info, Sync, NULL, 0, 0); | ||
info->Reset = M448Reset; | ||
info->Power = M448Power; | ||
MapIRQHook = M448CPUHook; | ||
GameStateRestore = StateRestore; | ||
AddExState(StateRegs, ~0, 0, 0); | ||
} |
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