// 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)));
space.install_read_bank(0x8000, 0x9fff, "prg0");
space.install_read_bank(0xa000, 0xbfff, "prg1");
space.install_read_bank(0xc000, 0xdfff, "prg2");
space.install_read_bank(0xe000, 0xffff, "prg3");
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)
if (m_cartslot->get_pcb_id() == STD_EXROM || m_cartslot->get_pcb_id() == STD_NROM368 || m_cartslot->get_pcb_id() == STD_DISKSYS
|| m_cartslot->get_pcb_id() == GG_NROM || m_cartslot->get_pcb_id() == CAMERICA_ALADDIN || m_cartslot->get_pcb_id() == SUNSOFT_DCS
|| m_cartslot->get_pcb_id() == BANDAI_DATACH || m_cartslot->get_pcb_id() == BANDAI_KARAOKE || m_cartslot->get_pcb_id() == BTL_2A03_PURITANS || m_cartslot->get_pcb_id() == AVE_MAXI15
|| m_cartslot->get_pcb_id() == KAISER_KS7022 || m_cartslot->get_pcb_id() == KAISER_KS7031 || m_cartslot->get_pcb_id() == KAISER_KS7037 || m_cartslot->get_pcb_id() == BMC_VT5201
|| m_cartslot->get_pcb_id() == UNL_LH32 || m_cartslot->get_pcb_id() == UNL_LH10 || m_cartslot->get_pcb_id() == UNL_2708 || m_cartslot->get_pcb_id() == UNL_RT01
|| m_cartslot->get_pcb_id() == UNL_43272 || m_cartslot->get_pcb_id() == BMC_G63IN1 || m_cartslot->get_pcb_id() == BMC_8157
|| m_cartslot->get_pcb_id() == BMC_GOLD150 || m_cartslot->get_pcb_id() == BMC_CH001
|| m_cartslot->get_pcb_id() == BMC_70IN1 || m_cartslot->get_pcb_id() == BMC_800IN1)
{
logerror("read_h installed!\n");
space.install_read_handler(0x8000, 0xffff, read8sm_delegate(*m_cartslot, FUNC(nes_cart_slot_device::read_h)));
}
if (m_cartslot->get_pcb_id() == BTL_SMB2JB || m_cartslot->get_pcb_id() == UNL_AC08 || m_cartslot->get_pcb_id() == UNL_SMB2J || m_cartslot->get_pcb_id() == BTL_09034A)
{
logerror("write_ex installed!\n");
space.install_write_handler(0x4020, 0x40ff, write8sm_delegate(*m_cartslot, FUNC(nes_cart_slot_device::write_ex)));
}
if (m_cartslot->get_pcb_id() == KAISER_KS7017 || m_cartslot->get_pcb_id() == UNL_603_5052 || m_cartslot->get_pcb_id() == STD_DISKSYS)
{
logerror("write_ex & read_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
//-------------------------------------------------
READ8_MEMBER(nes_base_state::nes_in0_r)
{
uint8_t ret = 0x40;
ret |= m_ctrl1->read_bit0();
ret |= m_ctrl1->read_bit34();
return ret;
}
READ8_MEMBER(nes_base_state::nes_in1_r)
{
uint8_t ret = 0x40;
ret |= m_ctrl2->read_bit0();
ret |= m_ctrl2->read_bit34();
return ret;
}
WRITE8_MEMBER(nes_base_state::nes_in0_w)
{
m_ctrl1->write(data);
m_ctrl2->write(data);
}
READ8_MEMBER(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;
}
READ8_MEMBER(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;
}
WRITE8_MEMBER(nes_state::fc_in0_w)
{
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, read8_delegate(*this, FUNC(nes_state::fc_in0_r)));
space.install_write_handler(0x4016, 0x4016, write8_delegate(*this, FUNC(nes_state::fc_in0_w)));
space.install_read_handler(0x4017, 0x4017, read8_delegate(*this, FUNC(nes_state::fc_in1_r)));
}