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CLK/Machines/Atari2600/Cartridges/Atari8k.hpp
2018-05-13 15:19:52 -04:00

65 lines
1.6 KiB
C++

//
// CartridgeAtari8k.h
// Clock Signal
//
// Created by Thomas Harte on 18/03/2017.
// Copyright 2017 Thomas Harte. All rights reserved.
//
#ifndef Atari2600_CartridgeAtari8k_hpp
#define Atari2600_CartridgeAtari8k_hpp
#include "Cartridge.hpp"
namespace Atari2600 {
namespace Cartridge {
class Atari8k: public BusExtender {
public:
Atari8k(uint8_t *rom_base, std::size_t rom_size) : BusExtender(rom_base, rom_size), rom_ptr_(rom_base) {}
void perform_bus_operation(CPU::MOS6502::BusOperation operation, uint16_t address, uint8_t *value) {
address &= 0x1fff;
if(!(address & 0x1000)) return;
if(address == 0x1ff8) rom_ptr_ = rom_base_;
else if(address == 0x1ff9) rom_ptr_ = rom_base_ + 4096;
if(isReadOperation(operation)) {
*value = rom_ptr_[address & 4095];
}
}
private:
uint8_t *rom_ptr_;
};
class Atari8kSuperChip: public BusExtender {
public:
Atari8kSuperChip(uint8_t *rom_base, std::size_t rom_size) : BusExtender(rom_base, rom_size), rom_ptr_(rom_base) {}
void perform_bus_operation(CPU::MOS6502::BusOperation operation, uint16_t address, uint8_t *value) {
address &= 0x1fff;
if(!(address & 0x1000)) return;
if(address == 0x1ff8) rom_ptr_ = rom_base_;
if(address == 0x1ff9) rom_ptr_ = rom_base_ + 4096;
if(isReadOperation(operation)) {
*value = rom_ptr_[address & 4095];
}
if(address < 0x1080) ram_[address & 0x7f] = *value;
else if(address < 0x1100 && isReadOperation(operation)) *value = ram_[address & 0x7f];
}
private:
uint8_t *rom_ptr_;
uint8_t ram_[128];
};
}
}
#endif /* Atari2600_CartridgeAtari8k_hpp */