// license:BSD-3-Clause // copyright-holders:Curt Coder /********************************************************************** Mega-Cart cartridge emulation **********************************************************************/ #include "emu.h" #include "megacart.h" //************************************************************************** // DEVICE DEFINITIONS //************************************************************************** DEFINE_DEVICE_TYPE(VIC20_MEGACART, vic20_megacart_device, "vic20_megacart", "VIC-20 Mega-Cart") //------------------------------------------------- // device_add_mconfig - add device configuration //------------------------------------------------- void vic20_megacart_device::device_add_mconfig(machine_config &config) { } //************************************************************************** // LIVE DEVICE //************************************************************************** //------------------------------------------------- // vic20_megacart_device - constructor //------------------------------------------------- vic20_megacart_device::vic20_megacart_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, VIC20_MEGACART, tag, owner, clock) , device_vic20_expansion_card_interface(mconfig, *this) , device_nvram_interface(mconfig, *this) , m_nvram(*this, "nvram", 0x2000, ENDIANNESS_LITTLE) , m_nvram_en(0) { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void vic20_megacart_device::device_start() { // state saving save_item(NAME(m_nvram_en)); } //------------------------------------------------- // device_reset - device-specific reset //------------------------------------------------- void vic20_megacart_device::device_reset() { } //------------------------------------------------- // vic20_cd_r - cartridge data read //------------------------------------------------- uint8_t vic20_megacart_device::vic20_cd_r(offs_t offset, uint8_t data, int ram1, int ram2, int ram3, int blk1, int blk2, int blk3, int blk5, int io2, int io3) { if (!ram1 || !ram2 || !ram3 || !io2 || !io3) { if (m_nvram_en) { data = m_nvram[offset & 0x1fff]; } } else if (!blk1 || !blk2 || !blk3) { } else if (!blk5) { } return data; } //------------------------------------------------- // vic20_cd_w - cartridge data write //------------------------------------------------- void vic20_megacart_device::vic20_cd_w(offs_t offset, uint8_t data, int ram1, int ram2, int ram3, int blk1, int blk2, int blk3, int blk5, int io2, int io3) { if (!ram1 || !ram2 || !ram3 || !io2) { if (m_nvram_en) { m_nvram[offset & 0x1fff] = data; } } else if (!blk1 || !blk2 || !blk3) { } else if (!blk5) { } else if (!io3) { if (m_nvram_en) { m_nvram[offset & 0x1fff] = data; } } }