diff options
Diffstat (limited to 'src/devices/bus/msx_slot/sony08.cpp')
-rw-r--r-- | src/devices/bus/msx_slot/sony08.cpp | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/src/devices/bus/msx_slot/sony08.cpp b/src/devices/bus/msx_slot/sony08.cpp new file mode 100644 index 00000000000..66a5f733e2d --- /dev/null +++ b/src/devices/bus/msx_slot/sony08.cpp @@ -0,0 +1,190 @@ +// license:BSD-3-Clause +// copyright-holders:Wilbert Pol +/* + + Emulation of the firmware mapper as found in Sony HB-F1XDJ and HB-F1XV machines. + +*/ + +#include "emu.h" +#include "sony08.h" + + +const device_type MSX_SLOT_SONY08 = &device_creator<msx_slot_sony08_device>; + + +msx_slot_sony08_device::msx_slot_sony08_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : device_t(mconfig, MSX_SLOT_SONY08, "MSX Internal SONY08", tag, owner, clock, "msx_slot_sony08", __FILE__) + , msx_internal_slot_interface() + , m_nvram(*this, "nvram") + , m_region(NULL) + , m_region_offset(0) + , m_rom(NULL) +{ + for (int i = 0; i < 8; i++) + { + m_selected_bank[i] = 0; + m_bank_base[i] = NULL; + } + memset(m_sram, 0, sizeof(m_sram)); +} + + +static MACHINE_CONFIG_FRAGMENT( sony08 ) + MCFG_NVRAM_ADD_0FILL("nvram") +MACHINE_CONFIG_END + + +machine_config_constructor msx_slot_sony08_device::device_mconfig_additions() const +{ + return MACHINE_CONFIG_NAME( sony08 ); +} + + +void msx_slot_sony08_device::set_rom_start(device_t &device, const char *region, UINT32 offset) +{ + msx_slot_sony08_device &dev = downcast<msx_slot_sony08_device &>(device); + + dev.m_region = region; + dev.m_region_offset = offset; +} + + +void msx_slot_sony08_device::device_start() +{ + assert(m_region != NULL ); + + memory_region *m_rom_region = owner()->memregion(m_region); + + // Sanity checks + if (m_rom_region == NULL ) + { + fatalerror("Rom slot '%s': Unable to find memory region '%s'\n", tag(), m_region); + } + if (m_rom_region->bytes() < m_region_offset + 0x100000) + { + fatalerror("Memory region '%s' is too small for the SONY08 firmware\n", m_region); + } + + m_rom = m_rom_region->base() + m_region_offset; + + m_nvram->set_base(m_sram, 0x4000); + + save_item(NAME(m_selected_bank)); + + machine().save().register_postload(save_prepost_delegate(FUNC(msx_slot_sony08_device::restore_banks), this)); + + restore_banks(); +} + + +void msx_slot_sony08_device::map_bank(int bank) +{ + if (bank < 2) + { + return; + } + + // Special banks + if (bank == 6 || bank == 7) + { + m_bank_base[bank] = m_rom + 0x80000 + (m_selected_bank[bank] * 0x800); + return; + } + + m_bank_base[bank] = m_rom + ((m_selected_bank[bank] * 0x2000) & 0xFFFFF); + if (bank == 2) + { + if (m_selected_bank[bank] & 0x80) + { + m_bank_base[0] = m_sram; + m_bank_base[1] = m_sram + 0x2000; + } + else + { + m_bank_base[0] = NULL; + m_bank_base[1] = NULL; + } + } +} + + +void msx_slot_sony08_device::restore_banks() +{ + for (int i = 0; i < 8; i++) + { + map_bank(i); + } +} + + +READ8_MEMBER(msx_slot_sony08_device::read) +{ + if (offset >= 0xc000) + { + return 0xFF; + } + + if ((offset & 0xf000) == 0x7000 && (m_selected_bank[3] & 0x80)) + { + return m_bank_base[6 + ((offset >> 11) & 0x01)][offset & 0x7ff]; + } + + const UINT8 *mem = m_bank_base[offset >> 13]; + + if (mem) + { + return mem[offset & 0x1fff]; + } + return 0xFF; +} + + +WRITE8_MEMBER(msx_slot_sony08_device::write) +{ + if (offset < 0x4000) + { + if (m_bank_base[0] != NULL) + { + m_sram[offset & 0x3fff] = data; + return; + } + } + + switch (offset) + { + case 0x4FFF: + m_selected_bank[2] = data; + map_bank(2); + break; + + case 0x6FFF: // 6000-7FFF + m_selected_bank[3] = data; + map_bank(3); + break; + + case 0x77FF: + m_selected_bank[6] = data; + map_bank(6); + break; + + case 0x7FFF: + m_selected_bank[7] = data; + map_bank(7); + break; + + case 0x8FFF: + m_selected_bank[4] = data; + map_bank(4); + break; + + case 0xAFFF: + m_selected_bank[5] = data; + map_bank(5); + break; + + default: + logerror("Unhandled write %02x to %04x\n", data, offset); + break; + } +} |