text: // license:BSD-3-Clause
  // copyright-holders:Nigel Barnes
  /**********************************************************************
  
      Slogger Plus 2
  
      The Plus 2 interface from Slogger has been designed to compliment
      the Slogger Rombox Plus and Acorn Plus 1 by offering further
      expansion capabilities. This has been achieved by providing two
      extra cartridge slots, three ROM sockets and connections for a
      Usr Port and even further expansion via two expansion points.
  
  **********************************************************************/
  
  
  #include "emu.h"
  #include "plus2.h"
  
  
  //**************************************************************************
  //  DEVICE DEFINITIONS
  //**************************************************************************
  
  DEFINE_DEVICE_TYPE(ELECTRON_PLUS2, electron_plus2_device, "electron_plus2", "Slogger Plus 2 Expansion")
  
  
  
  //-------------------------------------------------
  //  device_add_mconfig - add device configuration
  //-------------------------------------------------
  
  void electron_plus2_device::device_add_mconfig(machine_config &config)
  {
  	INPUT_MERGER_ANY_HIGH(config, m_irqs).output_handler().set(DEVICE_SELF_OWNER, FUNC(electron_expansion_slot_device::irq_w));
  
  	/* rom sockets */
  	GENERIC_SOCKET(config, m_rom[0], generic_plain_slot, "electron_rom", "bin,rom"); // ROM SLOT 13
  	m_rom[0]->set_device_load(FUNC(electron_plus2_device::rom1_load));
  	GENERIC_SOCKET(config, m_rom[1], generic_plain_slot, "electron_rom", "bin,rom"); // ROM SLOT 14
  	m_rom[1]->set_device_load(FUNC(electron_plus2_device::rom2_load));
  	GENERIC_SOCKET(config, m_rom[2], generic_plain_slot, "electron_rom", "bin,rom"); // ROM SLOT 15
  	m_rom[2]->set_device_load(FUNC(electron_plus2_device::rom3_load));
  
  	/* cartridges */
  	ELECTRON_CARTSLOT(config, m_cart[0], DERIVED_CLOCK(1, 1), electron_cart, nullptr);
  	m_cart[0]->irq_handler().set(m_irqs, FUNC(input_merger_device::in_w<0>));
  	m_cart[0]->nmi_handler().set(DEVICE_SELF_OWNER, FUNC(electron_expansion_slot_device::nmi_w));
  	ELECTRON_CARTSLOT(config, m_cart[1], DERIVED_CLOCK(1, 1), electron_cart, nullptr);
  	m_cart[1]->irq_handler().set(m_irqs, FUNC(input_merger_device::in_w<1>));
  	m_cart[1]->nmi_handler().set(DEVICE_SELF_OWNER, FUNC(electron_expansion_slot_device::nmi_w));
  
  	/* via */
  	MOS6522(config, m_via, DERIVED_CLOCK(1, 16));
  	m_via->readpb_handler().set(m_userport, FUNC(bbc_userport_slot_device::pb_r));
  	m_via->writepb_handler().set(m_userport, FUNC(bbc_userport_slot_device::pb_w));
  	m_via->cb1_handler().set(m_userport, FUNC(bbc_userport_slot_device::write_cb1));
  	m_via->cb2_handler().set(m_userport, FUNC(bbc_userport_slot_device::write_cb2));
  	m_via->irq_handler().set(m_irqs, FUNC(input_merger_device::in_w<2>));
  
  	/* user port */
  	BBC_USERPORT_SLOT(config, m_userport, bbc_userport_devices, nullptr);
  	m_userport->cb1_handler().set(m_via, FUNC(via6522_device::write_cb1));
  	m_userport->cb2_handler().set(m_via, FUNC(via6522_device::write_cb2));
  
  	/* pass-through */
  	ELECTRON_EXPANSION_SLOT(config, m_exp, DERIVED_CLOCK(1, 1), electron_expansion_devices, nullptr);
  	m_exp->irq_handler().set(m_irqs, FUNC(input_merger_device::in_w<3>));
  	m_exp->nmi_handler().set(DEVICE_SELF_OWNER, FUNC(electron_expansion_slot_device::nmi_w));
  }
  
  //**************************************************************************
  //  LIVE DEVICE
  //**************************************************************************
  
  //-------------------------------------------------
  //  electron_plus2_device - constructor
  //-------------------------------------------------
  
  electron_plus2_device::electron_plus2_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
  	: device_t(mconfig, ELECTRON_PLUS2, tag, owner, clock)
  	, device_electron_expansion_interface(mconfig, *this)
  	, m_irqs(*this, "irqs")
  	, m_exp(*this, "exp")
  	, m_via(*this, "via6522")
  	, m_rom(*this, "rom%u", 1)
  	, m_cart(*this, "cart%u", 1)
  	, m_userport(*this, "userport")
  	, m_romsel(0)
  {
  }
  
  
  //-------------------------------------------------
  //  device_start - device-specific startup
  //-------------------------------------------------
  
  void electron_plus2_device::device_start()
  {
  }
  
  
  //-------------------------------------------------
  //  expbus_r - expansion data read
  //-------------------------------------------------
  
  uint8_t electron_plus2_device::expbus_r(offs_t offset)
  {
  	uint8_t data = 0xff;
  
  	switch (offset >> 12)
  	{
  	case 0x8:
  	case 0x9:
  	case 0xa:
  	case 0xb:
  		switch (m_romsel)
  		{
  		case 4:
  		case 5:
  			data = m_cart[1]->read(offset & 0x3fff, 0, 0, m_romsel & 0x01, 1, 0);
  			break;
  		case 6:
  		case 7:
  			data = m_cart[0]->read(offset & 0x3fff, 0, 0, m_romsel & 0x01, 1, 0);
  			break;
  		case 13:
  			data &= m_cart[0]->read(offset & 0x3fff, 0, 0, m_romsel & 0x01, 0, 1);
  			data &= m_cart[1]->read(offset & 0x3fff, 0, 0, m_romsel & 0x01, 0, 1);
  			[[fallthrough]];
  		case 14:
  		case 15:
  			data &= m_rom[m_romsel - 13]->read_rom(offset & 0x3fff);
  			break;
  		}
  		break;
  
  	case 0xf:
  		switch (offset >> 8)
  		{
  		case 0xfc:
  			data &= m_cart[0]->read(offset & 0xff, 1, 0, m_romsel & 0x01, 0, 0);
  			data &= m_cart[1]->read(offset & 0xff, 1, 0, m_romsel & 0x01, 0, 0);
  
  			if (offset >= 0xfcb0 && offset < 0xfcc0)
  			{
  				data &= m_via->read(offset & 0x0f);
  			}
  			break;
  
  		case 0xfd:
  			data &= m_cart[0]->read(offset & 0xff, 0, 1, m_romsel & 0x01, 0, 0);
  			data &= m_cart[1]->read(offset & 0xff, 0, 1, m_romsel & 0x01, 0, 0);
  			break;
  		}
  	}
  
  	data &= m_exp->expbus_r(offset);
  
  	return data;
  }
  
  
  //-------------------------------------------------
  //  expbus_w - expansion data write
  //-------------------------------------------------
  
  void electron_plus2_device::expbus_w(offs_t offset, uint8_t data)
  {
  	switch (offset >> 12)
  	{
  	case 0x8:
  	case 0x9:
  	case 0xa:
  	case 0xb:
  		switch (m_romsel)
  		{
  		case 4:
  		case 5:
  			m_cart[1]->write(offset & 0x3fff, data, 0, 0, m_romsel & 0x01, 1, 0);
  			break;
  		case 6:
  		case 7:
  			m_cart[0]->write(offset & 0x3fff, data, 0, 0, m_romsel & 0x01, 1, 0);
  			break;
  		case 13:
  			m_cart[0]->write(offset & 0x3fff, data, 0, 0, m_romsel & 0x01, 0, 1);
  			m_cart[1]->write(offset & 0x3fff, data, 0, 0, m_romsel & 0x01, 0, 1);
  			break;
  		}
  		break;
  
  	case 0xf:
  		switch (offset >> 8)
  		{
  		case 0xfc:
  			m_cart[0]->write(offset & 0xff, data, 1, 0, m_romsel & 0x01, 0, 0);
  			m_cart[1]->write(offset & 0xff, data, 1, 0, m_romsel & 0x01, 0, 0);
  
  			if (offset >= 0xfcb0 && offset < 0xfcc0)
  			{
  				m_via->write(offset & 0x0f, data);
  			}
  			break;
  
  		case 0xfd:
  			m_cart[0]->write(offset & 0xff, data, 0, 1, m_romsel & 0x01, 0, 0);
  			m_cart[1]->write(offset & 0xff, data, 0, 1, m_romsel & 0x01, 0, 0);
  			break;
  
  		case 0xfe:
  			if (offset == 0xfe05)
  			{
  				m_romsel = data & 0x0f;
  			}
  			break;
  		}
  	}
  
  	m_exp->expbus_w(offset, data);
  }
  
  
  //**************************************************************************
  //  IMPLEMENTATION
  //**************************************************************************
  
  image_init_result electron_plus2_device::load_rom(device_image_interface &image, generic_slot_device *slot)
  {
  	uint32_t size = slot->common_get_size("rom");
  
  	// socket accepts 8K and 16K ROM only
  	if (size != 0x2000 && size != 0x4000)
  	{
  		image.seterror(image_error::INVALIDIMAGE, "Invalid size: Only 8K/16K is supported");
  		return image_init_result::FAIL;
  	}
  
  	slot->rom_alloc(0x4000, GENERIC_ROM8_WIDTH, ENDIANNESS_LITTLE);
  	slot->common_load_rom(slot->get_rom_base(), size, "rom");
  
  	// mirror 8K ROMs
  	uint8_t *crt = slot->get_rom_base();
  	if (size <= 0x2000) memcpy(crt + 0x2000, crt, 0x2000);
  
  	return image_init_result::PASS;
  }
  