// license:BSD-3-Clause
// copyright-holders:Brad Oliver,Fabio Priuli
/*****************************************************************************
nes.c
Nintendo Entertainment System (Famicom)
****************************************************************************/
#include "emu.h"
#include "cpu/m6502/m6502.h"
#include "includes/nes.h"
/***************************************************************************
FUNCTIONS
***************************************************************************/
// to be probably removed (it does nothing since a long time)
int nes_state::nes_ppu_vidaccess( int address, int data )
{
return data;
}
//-------------------------------------------------
// machine_reset
//-------------------------------------------------
void nes_state::machine_reset()
{
// Reset the mapper variables. Will also mark the char-gen ram as dirty
if (m_cartslot)
m_cartslot->pcb_reset();
m_maincpu->reset();
}
//-------------------------------------------------
// machine_start
//-------------------------------------------------
void nes_state::machine_start()
{
address_space &space = m_maincpu->space(AS_PROGRAM);
// CIRAM (Character Internal RAM)
// NES has 2KB of internal RAM which can be used to fill the 4x1KB banks of PPU RAM at $2000-$2fff
// Line A10 is exposed to the carts, so that games can change CIRAM mapping in PPU (we emulate this with the set_nt_mirroring
// function). CIRAM can also be disabled by the game (if e.g. VROM or cart RAM has to be used in PPU...
m_ciram = std::make_unique<uint8_t[]>(0x800);
// other pointers got set in the loading routine, because they 'belong' to the cart itself
m_io_disksel = ioport("FLIPDISK");
if (m_cartslot && m_cartslot->m_cart)
{
// Set up memory handlers
space.install_read_handler(0x4100, 0x5fff, read8sm_delegate(*m_cartslot, FUNC(nes_cart_slot_device::read_l)));
space.install_write_handler(0x4100, 0x5fff, write8sm_delegate(*m_cartslot, FUNC(nes_cart_slot_device::write_l)));
space.install_read_handler(0x6000, 0x7fff, read8sm_delegate(*m_cartslot, FUNC(nes_cart_slot_device::read_m)));
space.install_write_handler(0x6000, 0x7fff, write8sm_delegate(*m_cartslot, FUNC(nes_cart_slot_device::write_m)));
for(int i=0; i<4; i++)
space.install_read_bank(0x8000 + 0x2000*i, 0x9fff + 0x2000*i, m_prg_bank[i]);
space.install_write_handler(0x8000, 0xffff, write8sm_delegate(*m_cartslot, FUNC(nes_cart_slot_device::write_h)));
m_ppu->space(AS_PROGRAM).install_readwrite_handler(0, 0x1fff, read8sm_delegate(*m_cartslot->m_cart, FUNC(device_nes_cart_interface::chr_r)), write8sm_delegate(*m_cartslot->m_cart, FUNC(device_nes_cart_interface::chr_w)));
m_ppu->space(AS_PROGRAM).install_readwrite_handler(0x2000, 0x3eff, read8sm_delegate(*m_cartslot->m_cart, FUNC(device_nes_cart_interface::nt_r)), write8sm_delegate(*m_cartslot->m_cart, FUNC(device_nes_cart_interface::nt_w)));
m_ppu->set_scanline_callback(*m_cartslot->m_cart, FUNC(device_nes_cart_interface::scanline_irq));
m_ppu->set_hblank_callback(*m_cartslot->m_cart, FUNC(device_nes_cart_interface::hblank_irq));
m_ppu->set_latch(*m_cartslot->m_cart, FUNC(device_nes_cart_interface::ppu_latch));
// install additional handlers (read_h, read_ex, write_ex)
static const int r_h_pcbs[] =
{
AVE_MAXI15,
BANDAI_DATACH,
BANDAI_KARAOKE,
BATMAP_SRRX,
BMC_70IN1,
BMC_800IN1,
BMC_8157,
BMC_GOLD150,
BMC_TELETUBBIES,
BMC_VT5201,
BTL_PALTHENA,
CAMERICA_ALADDIN,
GG_NROM,
KAISER_KS7010,
KAISER_KS7022,
KAISER_KS7030,
KAISER_KS7031,
KAISER_KS7037,
KAISER_KS7057,
SACHEN_3013,
SACHEN_3014,
STD_DISKSYS,
STD_EXROM,
STD_NROM368,
SUNSOFT_DCS,
UNL_2708,
UNL_2A03PURITANS,
UNL_43272,
UNL_EH8813A,
UNL_LH10,
UNL_LH32,
UNL_RT01
};
static const int w_ex_pcbs[] =
{
BMC_N32_4IN1,
BTL_SMB2JB,
BTL_YUNG08,
UNL_AC08,
UNL_SMB2J
};
static const int rw_ex_pcbs[] =
{
BTL_09034A,
KAISER_KS7017,
STD_DISKSYS,
UNL_603_5052
};
int pcb_id = m_cartslot->get_pcb_id();
if (std::find(std::begin(r_h_pcbs), std::end(r_h_pcbs), pcb_id) != std::end(r_h_pcbs))
{
logerror("read_h installed!\n");
space.install_read_handler(0x8000, 0xffff, read8sm_delegate(*m_cartslot, FUNC(nes_cart_slot_device::read_h)));
}
if (std::find(std::begin(w_ex_pcbs), std::end(w_ex_pcbs), pcb_id) != std::end(w_ex_pcbs))
{
logerror("write_ex installed!\n");
space.install_write_handler(0x4020, 0x40ff, write8sm_delegate(*m_cartslot, FUNC(nes_cart_slot_device::write_ex)));
}
if (std::find(std::begin(rw_ex_pcbs), std::end(rw_ex_pcbs), pcb_id) != std::end(rw_ex_pcbs))
{
logerror("read_ex & write_ex installed!\n");
space.install_read_handler(0x4020, 0x40ff, read8sm_delegate(*m_cartslot, FUNC(nes_cart_slot_device::read_ex)));
space.install_write_handler(0x4020, 0x40ff, write8sm_delegate(*m_cartslot, FUNC(nes_cart_slot_device::write_ex)));
}
m_cartslot->pcb_start(m_ciram.get());
m_cartslot->m_cart->pcb_reg_postload(machine());
}
// register saves
save_item(NAME(m_last_frame_flip));
save_pointer(NAME(m_ciram), 0x800);
}
//-------------------------------------------------
// INPUTS
//-------------------------------------------------
uint8_t nes_base_state::nes_in0_r()
{
uint8_t ret = 0x40;
ret |= m_ctrl1->read_bit0();
ret |= m_ctrl1->read_bit34();
return ret;
}
uint8_t nes_base_state::nes_in1_r()
{
uint8_t ret = 0x40;
ret |= m_ctrl2->read_bit0();
ret |= m_ctrl2->read_bit34();
return ret;
}
void nes_base_state::nes_in0_w(uint8_t data)
{
m_ctrl1->write(data);
m_ctrl2->write(data);
}
uint8_t nes_state::fc_in0_r()
{
uint8_t ret = 0x40;
// bit 0 to controller port
ret |= m_ctrl1->read_bit0();
// expansion port bits (in the original FC, P2 controller was hooked to these lines
// too, so in principle some homebrew hardware modification could use the same
// connection with P1 controller too)
ret |= m_ctrl1->read_exp(0);
ret |= m_ctrl2->read_exp(0);
// at the same time, we might have a standard joypad connected to the expansion port which
// shall be read as P3 (this is needed here to avoid implementing the expansion port as a
// different device compared to the standard control port... it might be changed later)
ret |= (m_exp->read_bit0() << 1);
// finally, read the expansion port as expected
ret |= m_exp->read_exp(0);
return ret;
}
uint8_t nes_state::fc_in1_r()
{
uint8_t ret = 0x40;
// bit 0 to controller port
ret |= m_ctrl2->read_bit0();
// expansion port bits (in the original FC, P2 controller was hooked to these lines
// too, so in principle some homebrew hardware modification could use the same
// connection with P1 controller too)
ret |= m_ctrl1->read_exp(1);
ret |= m_ctrl2->read_exp(1);
// finally, read the expansion port as expected (standard pad cannot be hooked as P4, so
// no read_bit0 here)
ret |= m_exp->read_exp(1);
return ret;
}
void nes_state::fc_in0_w(uint8_t data)
{
m_ctrl1->write(data);
m_ctrl2->write(data);
m_exp->write(data);
}
void nes_state::init_famicom()
{
// setup alt input handlers for additional FC input devices
address_space &space = m_maincpu->space(AS_PROGRAM);
space.install_read_handler(0x4016, 0x4016, read8smo_delegate(*this, FUNC(nes_state::fc_in0_r)));
space.install_write_handler(0x4016, 0x4016, write8smo_delegate(*this, FUNC(nes_state::fc_in0_w)));
space.install_read_handler(0x4017, 0x4017, read8smo_delegate(*this, FUNC(nes_state::fc_in1_r)));
}