//NES-NROM-128 //NES-NROM-256 struct NES_NROM : Board { struct Settings { bool mirror; //0 = horizontal, 1 = vertical } settings; uint8 prg_read(unsigned addr) { if(addr & 0x8000) return prgrom.read(addr); return cpu.mdr(); } void prg_write(unsigned addr, uint8 data) { } uint8 chr_read(unsigned addr) { if(addr & 0x2000) { if(settings.mirror == 0) addr = ((addr & 0x0800) >> 1) | (addr & 0x03ff); return ppu.ciram_read(addr & 0x07ff); } if(chrram.size) return chrram.read(addr); return chrrom.read(addr); } void chr_write(unsigned addr, uint8 data) { if(addr & 0x2000) { if(settings.mirror == 0) addr = ((addr & 0x0800) >> 1) | (addr & 0x03ff); return ppu.ciram_write(addr & 0x07ff, data); } if(chrram.size) return chrram.write(addr, data); } void serialize(serializer& s) { Board::serialize(s); } NES_NROM(Markup::Node& document) : Board(document) { settings.mirror = document["cartridge"]["mirror"]["mode"].data == "vertical" ? 1 : 0; } };