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Rewrite mapper 222 to use modular VRC2/4 emulation, and improve its IRQ counter.

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NewRisingSun
2025-04-07 23:00:03 +02:00
committed by LibretroAdmin
parent 6804388ac7
commit af60e17d0b
1 changed files with 66 additions and 69 deletions
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135
src/boards/222.c
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@@ -1,7 +1,7 @@
/* FCE Ultra - NES/Famicom Emulator /* FCE Ultra - NES/Famicom Emulator
* *
* Copyright notice for this file: * Copyright notice for this file:
* Copyright (C) 2005 CaH4e3 * Copyright (C) 2025 NewRisingSun
* *
* This program is free software; you can redistribute it and/or modify * 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 * it under the terms of the GNU General Public License as published by
@@ -16,86 +16,83 @@
* You should have received a copy of the GNU General Public License * You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software * along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* (VRC4 mapper)
*
*/ */
#include "mapinc.h" #include "mapinc.h"
#include "vrc2and4.h"
static uint8 IRQCount; /*, IRQPre; */ static uint8 clockMode;
static uint8 IRQa; static uint8 pending;
static uint8 prg_reg[2]; static uint8 counter1;
static uint8 chr_reg[8]; static uint8 counter2;
static uint8 mirr; static uint8 prescaler;
static SFORMAT StateRegs[] = static SFORMAT Mapper222_stateRegs[] ={
{ { &clockMode, 1, "CLKM" },
{ &IRQCount, 1, "IRQC" }, { &pending, 1, "PEND" },
{ &IRQa, 1, "IRQA" }, { &counter1, 1, "CNT1" },
{ prg_reg, 2, "PRG" }, { &counter2, 1, "CNT2" },
{ chr_reg, 8, "CHR" }, { &prescaler, 1, "PRES" },
{ &mirr, 1, "MIRR" },
{ 0 } { 0 }
}; };
static void M222IRQ(void) { static void sync () {
if (IRQa) { VRC24_syncPRG(0x01F, 0x000);
IRQCount++; VRC24_syncCHR(0x1FF, 0x000);
if (IRQCount >= 238) { VRC24_syncMirror();
X6502_IRQBegin(FCEU_IQEXT); }
/* IRQa=0; */
DECLFW(Mapper222_nibblizeCHR) {
if (~A &1) {
VRC24_writeReg(A, V);
VRC24_writeReg(A |1, V >>4);
}
}
DECLFW(Mapper222_writeIRQ) {
switch(A &3) {
case 0: clockMode =0;
break;
case 1: pending =false;
if (!clockMode) {
counter1 =V &0xF;
counter2 =V >>4;
}
break;
case 2: clockMode =1;
break;
}
}
void FP_FASTAPASS(1) Mapper222_cpuCycle(int a) {
while (a--) {
uint8 previousPrescaler =prescaler;
if (pending)
prescaler =0;
else
prescaler++;
if (clockMode && ~previousPrescaler &0x40 && prescaler &0x40) {
if (++counter1 ==0xF && ++counter2 ==0xF) pending =1;
counter1 &=0xF;
counter2 &=0xF;
} }
if (pending)
X6502_IRQBegin(FCEU_IQEXT);
else
X6502_IRQEnd(FCEU_IQEXT);
} }
} }
static void Sync(void) { void Mapper222_power(void) {
int i; clockMode =pending =counter1 =counter2 =prescaler =0;
setprg8(0x8000, prg_reg[0]); VRC24_power();
setprg8(0xA000, prg_reg[1]); SetWriteHandler(0xB000, 0xEFFF, Mapper222_nibblizeCHR);
for (i = 0; i < 8; i++) SetWriteHandler(0xF000, 0xFFFF, Mapper222_writeIRQ);
setchr1(i << 10, chr_reg[i]);
setmirror(mirr ^ 1);
} }
static DECLFW(M222Write) { void Mapper222_Init (CartInfo *info) {
switch (A & 0xF003) { VRC24_init(info, sync, 0x01, 0x02, 0, 0, 0);
case 0x8000: prg_reg[0] = V; break; AddExState(Mapper222_stateRegs, ~0, 0, 0);
case 0x9000: mirr = V & 1; break; info->Power =Mapper222_power;
case 0xA000: prg_reg[1] = V; break; MapIRQHook =Mapper222_cpuCycle;
case 0xB000: chr_reg[0] = V; break;
case 0xB002: chr_reg[1] = V; break;
case 0xC000: chr_reg[2] = V; break;
case 0xC002: chr_reg[3] = V; break;
case 0xD000: chr_reg[4] = V; break;
case 0xD002: chr_reg[5] = V; break;
case 0xE000: chr_reg[6] = V; break;
case 0xE002: chr_reg[7] = V; break;
#if 0
case 0xF000: FCEU_printf("%04x:%02x %d\n",A,V,scanline); IRQa=V; if(!V)IRQPre=0; X6502_IRQEnd(FCEU_IQEXT); break;
case 0xF001: FCEU_printf("%04x:%02x %d\n",A,V,scanline); IRQCount=V; break;
case 0xF002: FCEU_printf("%04x:%02x %d\n",A,V,scanline); break;
case 0xD001: IRQa=V; X6502_IRQEnd(FCEU_IQEXT); FCEU_printf("%04x:%02x %d\n",A,V,scanline); break;
case 0xC001: IRQPre=16; FCEU_printf("%04x:%02x %d\n",A,V,scanline); break;
#endif
case 0xF000: IRQa = IRQCount = V; if (scanline < 240) IRQCount -= 8; else IRQCount += 4; X6502_IRQEnd(FCEU_IQEXT); break;
}
Sync();
}
static void M222Power(void) {
setprg16(0xC000, ~0);
SetReadHandler(0x8000, 0xFFFF, CartBR);
SetWriteHandler(0x8000, 0xFFFF, M222Write);
}
static void StateRestore(int version) {
Sync();
}
void Mapper222_Init(CartInfo *info) {
info->Power = M222Power;
GameHBIRQHook = M222IRQ;
GameStateRestore = StateRestore;
AddExState(&StateRegs, ~0, 0, 0);
} }