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// license:BSD-3-Clause
// copyright-holders:Curt Coder
/**********************************************************************
Mega-Cart cartridge emulation
**********************************************************************/
#include "emu.h"
#include "megacart.h"
//**************************************************************************
// DEVICE DEFINITIONS
//**************************************************************************
DEFINE_DEVICE_TYPE(VIC20_MEGACART, vic20_megacart_device, "vic20_megacart", "VIC-20 Mega-Cart")
//-------------------------------------------------
// device_add_mconfig - add device configuration
//-------------------------------------------------
void vic20_megacart_device::device_add_mconfig(machine_config &config)
{
}
//**************************************************************************
// LIVE DEVICE
//**************************************************************************
//-------------------------------------------------
// vic20_megacart_device - constructor
//-------------------------------------------------
vic20_megacart_device::vic20_megacart_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
: device_t(mconfig, VIC20_MEGACART, tag, owner, clock)
, device_vic20_expansion_card_interface(mconfig, *this)
, device_nvram_interface(mconfig, *this)
, m_nvram(*this, "nvram", 0x2000, ENDIANNESS_LITTLE)
, m_nvram_en(0)
{
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void vic20_megacart_device::device_start()
{
// state saving
save_item(NAME(m_nvram_en));
}
//-------------------------------------------------
// device_reset - device-specific reset
//-------------------------------------------------
void vic20_megacart_device::device_reset()
{
}
void vic20_megacart_device::nvram_default()
{
}
bool vic20_megacart_device::nvram_read(util::read_stream &file)
{
auto const [err, actual] = read(file, m_nvram, 0x2000);
return !err && (actual == 0x2000);
}
bool vic20_megacart_device::nvram_write(util::write_stream &file)
{
auto const [err, actual] = write(file, m_nvram, 0x2000);
return !err;
}
//-------------------------------------------------
// vic20_cd_r - cartridge data read
//-------------------------------------------------
uint8_t vic20_megacart_device::vic20_cd_r(offs_t offset, uint8_t data, int ram1, int ram2, int ram3, int blk1, int blk2, int blk3, int blk5, int io2, int io3)
{
if (!ram1 || !ram2 || !ram3 || !io2 || !io3)
{
if (m_nvram_en)
{
data = m_nvram[offset & 0x1fff];
}
}
else if (!blk1 || !blk2 || !blk3)
{
}
else if (!blk5)
{
}
return data;
}
//-------------------------------------------------
// vic20_cd_w - cartridge data write
//-------------------------------------------------
void vic20_megacart_device::vic20_cd_w(offs_t offset, uint8_t data, int ram1, int ram2, int ram3, int blk1, int blk2, int blk3, int blk5, int io2, int io3)
{
if (!ram1 || !ram2 || !ram3 || !io2)
{
if (m_nvram_en)
{
m_nvram[offset & 0x1fff] = data;
}
}
else if (!blk1 || !blk2 || !blk3)
{
}
else if (!blk5)
{
}
else if (!io3)
{
if (m_nvram_en)
{
m_nvram[offset & 0x1fff] = data;
}
}
}
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