mirror of
https://github.com/TomHarte/CLK.git
synced 2024-11-05 06:05:27 +00:00
43 lines
841 B
C++
43 lines
841 B
C++
//
|
|
// CartridgeMegaBoy.h
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 18/03/2017.
|
|
// Copyright 2017 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#pragma once
|
|
|
|
#include "Cartridge.hpp"
|
|
|
|
namespace Atari2600::Cartridge {
|
|
|
|
class MegaBoy: public BusExtender {
|
|
public:
|
|
MegaBoy(uint8_t *rom_base, std::size_t rom_size) :
|
|
BusExtender(rom_base, rom_size),
|
|
rom_ptr_(rom_base),
|
|
current_page_(0) {
|
|
}
|
|
|
|
void perform_bus_operation(CPU::MOS6502::BusOperation operation, uint16_t address, uint8_t *value) {
|
|
address &= 0x1fff;
|
|
if(!(address & 0x1000)) return;
|
|
|
|
if(address == 0x1ff0) {
|
|
current_page_ = (current_page_ + 1) & 15;
|
|
rom_ptr_ = rom_base_ + current_page_ * 4096;
|
|
}
|
|
|
|
if(isReadOperation(operation)) {
|
|
*value = rom_ptr_[address & 4095];
|
|
}
|
|
}
|
|
|
|
private:
|
|
uint8_t *rom_ptr_;
|
|
uint8_t current_page_;
|
|
};
|
|
|
|
}
|