44 lines
1.6 KiB
C
44 lines
1.6 KiB
C
/* FCE Ultra - NES/Famicom Emulator
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*
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* Copyright notice for this file:
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* Copyright (C) 2025 NewRisingSun
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "mapinc.h"
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#include "asic_latch.h"
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static void sync () {
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if (Latch_address &0x20) { /* First chip: 256 KiB */
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setprg16(0x8000, Latch_address >>1 &0x08 | Latch_data &0x07);
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setprg16(0xC000, Latch_address >>1 &0x08 | 0x07);
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} else { /* Second chip: 128 KiB (boot) */
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setprg16(0x8000, 0x10 | Latch_address >>1 &0x07);
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setprg16(0xC000, 0x10 | Latch_address >>1 &0x07);
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}
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setchr8(0);
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setmirror(Latch_address &1? MI_H: MI_V);
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}
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static void trapLatchWrite (uint16 *newAddress, uint8 *newValue, uint8 romValue) { /* The address bits are only updated on a falling edge of D3. */
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if (!(Latch_data &0x08 && ~*newValue &0x08)) *newAddress = Latch_address;
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}
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void Mapper589_Init (CartInfo *info) {
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Latch_init(info, sync, 0x8000, 0xFFFF, trapLatchWrite);
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info->Reset = Latch_clear;
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}
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