Files
ci-libretro-fceumm/src/boards/544.c
2025-09-12 21:59:27 +02:00

98 lines
2.5 KiB
C

/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
* Copyright (C) 2025 NewRisingSun
*
* 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
*/
#include "mapinc.h"
#include "asic_vrc2and4.h"
#include "cartram.h"
static uint8 nt[4];
static uint8 prg;
static uint8 mask;
static uint8 compare;
extern uint32 RefreshAddr;
static writefunc writePPU;
static SFORMAT stateRegs[] ={
{ nt, 4, "EXPN" },
{ &prg, 1, "PRGC" },
{ &mask, 1, "CHRM" },
{ &compare, 1, "CHRC" },
{ 0 }
};
static void sync () {
int bank;
VRC24_syncWRAM(0);
VRC24_syncPRG(0x01F, 0x000);
for (bank =0; bank <8; bank++) setchr1r((VRC24_getCHRBank(bank) &mask) ==compare? 0x10: 0x00, bank <<10, VRC24_getCHRBank(bank));
setmirrorw(nt[0] &1, nt[1] &1, nt[2] &1, nt[3] &1);
}
static const uint8 compares[8] = { 0x28, 0x00, 0x4C, 0x64, 0x46, 0x7C, 0x04, 0xFF };
static DECLFW (interceptPPUWrite) {
if (~RefreshAddr &0x2000) {
int bank =VRC24_getCHRBank(RefreshAddr >>10 &7);
if (bank &0x80) {
if (bank &0x10) {
mask =0x00;
compare =0xFF;
} else {
int index =(bank &0x02? 1: 0) | (bank &0x08? 2: 0) | (bank &0x40? 4: 0);
mask =bank &0x40? 0xFE: 0xFC;
compare =compares[index];
}
sync();
}
}
writePPU(A, V);
}
static int getPRGBank (uint8 bank) {
return bank ==2? prg: VRC24_getPRGBank(bank);
}
static DECLFW (externalSelect) {
if (A &4)
nt[A &3] =V;
else
prg =V;
sync();
}
static void power (void) {
mask =0xFC;
compare =0x28;
nt[0] =nt[1] =0xE0;
nt[2] =nt[3] =0xE1;
prg =0xFE;
VRC24_power();
writePPU =GetWriteHandler(0x2007);
SetWriteHandler(0x2007, 0x2007, interceptPPUWrite);
}
void Mapper544_Init (CartInfo *info) {
VRC4_init(info, sync, 0x400, 0x800, 1, getPRGBank, NULL, NULL, NULL, externalSelect);
CartRAM_init(info, 8, 2);
info->Power =power;
AddExState(stateRegs, ~0, 0, 0);
}