/********************************************************************** StarPoint Software StarDOS cartridge emulation Copyright MESS Team. Visit http://mamedev.org for licensing and usage restrictions. **********************************************************************/ /* PCB Layout ---------- |===========================| |=| | |=| LS30 | |=| LS157 | |=| LS00 | |=| ROM | |=| 7407 | |=| | |=| SW1| |===========================| ROM - Toshiba TMM271128D-25 16Kx8 EPROM */ #include "c64_stardos.h" //************************************************************************** // MACROS/CONSTANTS //************************************************************************** #define IO1_FULL_CHARGE 27 #define IO2_FULL_CHARGE 42 //************************************************************************** // DEVICE DEFINITIONS //************************************************************************** const device_type C64_STARDOS = &device_creator; //------------------------------------------------- // INPUT_PORTS( c64_stardos ) //------------------------------------------------- static INPUT_PORTS_START( c64_stardos ) PORT_START("RESET") PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_NAME("Reset") PORT_CODE(KEYCODE_F11) PORT_WRITE_LINE_DEVICE_MEMBER(DEVICE_SELF_OWNER, c64_expansion_slot_device, reset_w) INPUT_PORTS_END //------------------------------------------------- // input_ports - device-specific input ports //------------------------------------------------- ioport_constructor c64_stardos_cartridge_device::device_input_ports() const { return INPUT_PORTS_NAME( c64_stardos ); } //************************************************************************** // INLINE HELPERS //************************************************************************** //------------------------------------------------- // charge_io1_capacitor - //------------------------------------------------- inline void c64_stardos_cartridge_device::charge_io1_capacitor() { m_io1_charge++; if (m_io1_charge >= IO1_FULL_CHARGE) { m_exrom = 0; m_io1_charge = 0; } } //------------------------------------------------- // charge_io2_capacitor - //------------------------------------------------- void c64_stardos_cartridge_device::charge_io2_capacitor() { m_io2_charge++; if (m_io2_charge >= IO2_FULL_CHARGE) { m_exrom = 1; m_io2_charge = 0; } } //************************************************************************** // LIVE DEVICE //************************************************************************** //------------------------------------------------- // c64_stardos_cartridge_device - constructor //------------------------------------------------- c64_stardos_cartridge_device::c64_stardos_cartridge_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : device_t(mconfig, C64_STARDOS, "C64 StarDOS cartridge", tag, owner, clock), device_c64_expansion_card_interface(mconfig, *this), m_io1_charge(0), m_io2_charge(0) { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void c64_stardos_cartridge_device::device_start() { // state saving save_item(NAME(m_io1_charge)); save_item(NAME(m_io2_charge)); } //------------------------------------------------- // c64_cd_r - cartridge data read //------------------------------------------------- UINT8 c64_stardos_cartridge_device::c64_cd_r(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2) { if (!roml || !romh) { // TODO BITSWAP8(7,6,5,4,3,1,2,0) ? data = m_roml[offset & 0x3fff]; } else if (!io1) { charge_io1_capacitor(); } else if (!io2) { charge_io2_capacitor(); } return data; } //------------------------------------------------- // c64_cd_w - cartridge data write //------------------------------------------------- void c64_stardos_cartridge_device::c64_cd_w(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2) { if (!io1) { charge_io1_capacitor(); } else if (!io2) { charge_io2_capacitor(); } } //------------------------------------------------- // c64_game_r - GAME read //------------------------------------------------- int c64_stardos_cartridge_device::c64_game_r(offs_t offset, int sphi2, int ba, int rw, int hiram) { return !(sphi2 && ba & rw & ((offset & 0xe000) == 0xe000) & hiram); } //------------------------------------------------- // c64_exrom_r - EXROM read //------------------------------------------------- int c64_stardos_cartridge_device::c64_exrom_r(offs_t offset, int sphi2, int ba, int rw, int hiram) { return (BIT(offset, 13)) ? 1 : m_exrom; }