// license:BSD-3-Clause // copyright-holders:Curt Coder /********************************************************************** Brown Boxes Double Quick Brown Box emulation **********************************************************************/ /* TODO: - 64/128 mode switch - dump of the initial NVRAM contents */ #include "emu.h" #include "dqbb.h" //************************************************************************** // DEVICE DEFINITIONS //************************************************************************** DEFINE_DEVICE_TYPE(C64_DQBB, c64_dqbb_cartridge_device, "c64_dqbb", "C64 Double Quick Brown Box cartridge") //************************************************************************** // LIVE DEVICE //************************************************************************** //------------------------------------------------- // c64_dqbb_cartridge_device - constructor //------------------------------------------------- c64_dqbb_cartridge_device::c64_dqbb_cartridge_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, C64_DQBB, tag, owner, clock), device_c64_expansion_card_interface(mconfig, *this), device_nvram_interface(mconfig, *this), m_cs(0), m_we(0) { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void c64_dqbb_cartridge_device::device_start() { // allocate memory m_nvram = std::make_unique(0x4000); save_pointer(NAME(m_nvram), 0x4000); // state saving save_item(NAME(m_cs)); save_item(NAME(m_we)); } //------------------------------------------------- // device_reset - device-specific reset //------------------------------------------------- void c64_dqbb_cartridge_device::device_reset() { m_exrom = 0; // TODO 1 in 128 mode m_game = 1; m_cs = 0; m_we = 0; } //------------------------------------------------- // c64_cd_r - cartridge data read //------------------------------------------------- uint8_t c64_dqbb_cartridge_device::c64_cd_r(offs_t offset, uint8_t data, int sphi2, int ba, int roml, int romh, int io1, int io2) { if (!m_cs && (!roml || !romh)) { data = m_nvram[offset & 0x3fff]; } return data; } //------------------------------------------------- // c64_cd_w - cartridge data write //------------------------------------------------- void c64_dqbb_cartridge_device::c64_cd_w(offs_t offset, uint8_t data, int sphi2, int ba, int roml, int romh, int io1, int io2) { if (!m_cs && m_we && (offset >= 0x8000 && offset < 0xc000)) { m_nvram[offset & 0x3fff] = data; } else if (!io1) { /* bit description 0 1 2 GAME 3 4 WE 5 6 EXROM 7 _CS */ m_exrom = !BIT(data, 6); m_game = !BIT(data, 2); m_we = BIT(data, 4); m_cs = BIT(data, 7); } }