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48 lines
952 B
C++
48 lines
952 B
C++
//
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// CartridgeMegaBoy.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_CartridgeMegaBoy_hpp
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#define Atari2600_CartridgeMegaBoy_hpp
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#include "Cartridge.hpp"
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namespace Atari2600 {
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namespace Cartridge {
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class MegaBoy: public BusExtender {
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public:
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MegaBoy(uint8_t *rom_base, std::size_t rom_size) :
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BusExtender(rom_base, rom_size),
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rom_ptr_(rom_base),
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current_page_(0) {
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}
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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 == 0x1ff0) {
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current_page_ = (current_page_ + 1) & 15;
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rom_ptr_ = rom_base_ + current_page_ * 4096;
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}
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if(isReadOperation(operation)) {
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*value = rom_ptr_[address & 4095];
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}
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}
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private:
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uint8_t *rom_ptr_;
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uint8_t current_page_;
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};
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}
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}
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#endif /* CartridgeMegaBoy_h */
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