// license:BSD-3-Clause // copyright-holders:Curt Coder /********************************************************************** Super Explode! cartridge emulation **********************************************************************/ #include "emu.h" #include "super_explode.h" //************************************************************************** // MACROS/CONSTANTS //************************************************************************** // t = R*C = 3.3K * 0.47uF * 40% Vtr = 792.2905424610516 usec // (3.3K pull-up on the EXROM line inside the C64, PLA Vih min = 2.0V = 40% of 5.0V) #define TIMER_PERIOD 792 //************************************************************************** // DEVICE DEFINITIONS //************************************************************************** DEFINE_DEVICE_TYPE(C64_SUPER_EXPLODE, c64_super_explode_cartridge_device, "c64_super_explode", "C64 Super Explode! cartridge") //************************************************************************** // LIVE DEVICE //************************************************************************** //------------------------------------------------- // c64_super_explode_cartridge_device - constructor //------------------------------------------------- c64_super_explode_cartridge_device::c64_super_explode_cartridge_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, C64_SUPER_EXPLODE, tag, owner, clock), device_c64_expansion_card_interface(mconfig, *this), m_bank(0), m_exrom_timer(nullptr) { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void c64_super_explode_cartridge_device::device_start() { // allocate timer m_exrom_timer = timer_alloc(); // state saving save_item(NAME(m_bank)); } //------------------------------------------------- // device_reset - device-specific reset //------------------------------------------------- void c64_super_explode_cartridge_device::device_reset() { m_bank = 0; m_exrom = 0; m_exrom_timer->adjust(attotime::from_usec(TIMER_PERIOD), 0); } //------------------------------------------------- // device_timer - handler timer events //------------------------------------------------- void c64_super_explode_cartridge_device::device_timer(emu_timer &timer, device_timer_id id, int param) { m_exrom = 1; } //------------------------------------------------- // c64_cd_r - cartridge data read //------------------------------------------------- uint8_t c64_super_explode_cartridge_device::c64_cd_r(offs_t offset, uint8_t data, int sphi2, int ba, int roml, int romh, int io1, int io2) { if (!roml) { m_exrom = 0; m_exrom_timer->adjust(attotime::from_usec(TIMER_PERIOD), 0); data = m_roml[(m_bank << 13) | (offset & 0x1fff)]; } else if (!io1) { m_exrom = 0; m_exrom_timer->adjust(attotime::from_usec(TIMER_PERIOD), 0); } else if (!io2) { data = m_roml[(m_bank << 13) | (offset & 0x1fff)]; } return data; } //------------------------------------------------- // c64_cd_w - cartridge data write //------------------------------------------------- void c64_super_explode_cartridge_device::c64_cd_w(offs_t offset, uint8_t data, int sphi2, int ba, int roml, int romh, int io1, int io2) { if (!io1) { m_exrom = 0; m_exrom_timer->adjust(attotime::from_usec(TIMER_PERIOD), 0); } else if (!io2) { m_bank = BIT(data, 7); } }