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49 lines
988 B
C++
49 lines
988 B
C++
//
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// CartridgeParkerBros.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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#pragma once
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#include "Cartridge.hpp"
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namespace Atari2600::Cartridge {
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class ParkerBros: public BusExtender {
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public:
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ParkerBros(const uint8_t *const rom_base, const std::size_t rom_size) :
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BusExtender(rom_base, rom_size)
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{
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rom_ptr_[0] = rom_base + 4096;
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rom_ptr_[1] = rom_ptr_[0] + 1024;
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rom_ptr_[2] = rom_ptr_[1] + 1024;
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rom_ptr_[3] = rom_ptr_[2] + 1024;
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}
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void perform_bus_operation(
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const CPU::MOS6502::BusOperation operation,
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uint16_t address,
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uint8_t *const value
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) {
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address &= 0x1fff;
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if(!(address & 0x1000)) return;
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if(address >= 0x1fe0 && address < 0x1ff8) {
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int slot = (address >> 3)&3;
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rom_ptr_[slot] = rom_base_ + ((address & 7) * 1024);
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}
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if(isReadOperation(operation)) {
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*value = rom_ptr_[(address >> 10)&3][address & 1023];
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}
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}
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private:
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const uint8_t *rom_ptr_[4];
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};
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}
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