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42 lines
1.0 KiB
C++
42 lines
1.0 KiB
C++
//
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// CartridgeCBSRAMPlus.h
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// Clock Signal
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//
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// Created by Thomas Harte on 18/03/2017.
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// Copyright 2017 Thomas Harte. All rights reserved.
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//
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#ifndef Atari2600_CartridgeCBSRAMPlus_hpp
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#define Atari2600_CartridgeCBSRAMPlus_hpp
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#include "Cartridge.hpp"
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namespace Atari2600::Cartridge {
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class CBSRAMPlus: public BusExtender {
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public:
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CBSRAMPlus(uint8_t *rom_base, std::size_t rom_size) : BusExtender(rom_base, rom_size), rom_ptr_(rom_base) {}
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void perform_bus_operation(CPU::MOS6502::BusOperation operation, uint16_t address, uint8_t *value) {
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address &= 0x1fff;
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if(!(address & 0x1000)) return;
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if(address >= 0x1ff8 && address <= 0x1ffa) rom_ptr_ = rom_base_ + (address - 0x1ff8) * 4096;
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if(isReadOperation(operation)) {
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*value = rom_ptr_[address & 4095];
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}
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if(address < 0x1100) ram_[address & 0xff] = *value;
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else if(address < 0x1200 && isReadOperation(operation)) *value = ram_[address & 0xff];
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}
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private:
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uint8_t *rom_ptr_;
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uint8_t ram_[256];
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};
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}
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#endif /* Atari2600_CartridgeCBSRAMPlus_hpp */
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