diff options
Diffstat (limited to 'src/devices/bus/msx_slot/panasonic08.c')
-rw-r--r-- | src/devices/bus/msx_slot/panasonic08.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/src/devices/bus/msx_slot/panasonic08.c b/src/devices/bus/msx_slot/panasonic08.c new file mode 100644 index 00000000000..df78f76a27b --- /dev/null +++ b/src/devices/bus/msx_slot/panasonic08.c @@ -0,0 +1,182 @@ +// license:BSD-3-Clause +// copyright-holders:Wilbert Pol +/* + + Emulation of the firmware mapper as found in Panasonic FS-A1WX andFS-A1WSX machines. + +Todo: +- Anything besides the basic mapping +- SRAM? +*/ + +#include "emu.h" +#include "panasonic08.h" + + +const device_type MSX_SLOT_PANASONIC08 = &device_creator<msx_slot_panasonic08_device>; + + +msx_slot_panasonic08_device::msx_slot_panasonic08_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : device_t(mconfig, MSX_SLOT_PANASONIC08, "MSX Internal Panasonic08", tag, owner, clock, "msx_slot_panasonic08", __FILE__) + , msx_internal_slot_interface() + , m_nvram(*this, "nvram") + , m_region(NULL) + , m_region_offset(0) + , m_rom(NULL) + , m_control(0) +{ + for (int i = 0; i < 8; i++) + { + m_selected_bank[i] = 0; + m_bank_base[i] = 0; + } +} + + +static MACHINE_CONFIG_FRAGMENT( panasonic08 ) + MCFG_NVRAM_ADD_0FILL("nvram") +MACHINE_CONFIG_END + + +machine_config_constructor msx_slot_panasonic08_device::device_mconfig_additions() const +{ + return MACHINE_CONFIG_NAME( panasonic08 ); +} + + +void msx_slot_panasonic08_device::set_rom_start(device_t &device, const char *region, UINT32 offset) +{ + msx_slot_panasonic08_device &dev = downcast<msx_slot_panasonic08_device &>(device); + + dev.m_region = region; + dev.m_region_offset = offset; +} + + +void msx_slot_panasonic08_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 + 0x200000) + { + fatalerror("Memory region '%s' is too small for the FS4600 firmware\n", m_region); + } + + m_sram.resize(0x4000); + + m_nvram->set_base(&m_sram[0], 0x4000); + + m_rom = m_rom_region->base() + m_region_offset; + + save_item(NAME(m_selected_bank)); + save_item(NAME(m_control)); + + machine().save().register_postload(save_prepost_delegate(FUNC(msx_slot_panasonic08_device::restore_banks), this)); + + restore_banks(); +} + + +void msx_slot_panasonic08_device::map_bank(int bank) +{ + if (m_selected_bank[bank] >= 0x80 && m_selected_bank[bank] < 0x84) // Are these banks were sram is present? Mirroring? + { + logerror("panasonic08: mapping bank %d to sram\n", bank); + m_bank_base[bank] = &m_sram[((m_selected_bank[bank] & 0x7f) * 0x2000) & 0x3fff]; + } + else + { + m_bank_base[bank] = m_rom + ( ( m_selected_bank[bank] * 0x2000 ) & 0x1fffff ); + } +} + + +void msx_slot_panasonic08_device::restore_banks() +{ + for (int i = 0; i < 8; i++) + { + map_bank(i); + } +} + + +READ8_MEMBER(msx_slot_panasonic08_device::read) +{ + if (m_control & 0x04) + { + // 7ff0 - 6000 + // 7ff1 - 6400 + // 7ff2 - 6800 + // 7ff3 - 6c00 + // 7ff4 - 7000 + // 7ff5 - 7800 + if (offset >= 0x7ff0 && offset < 0x7ff6) // maybe 7ff8 would make more sense here?? + { + return m_selected_bank[offset - 0x7ff0]; + } + } + return m_bank_base[offset >> 13][offset & 0x1fff]; +} + + +WRITE8_MEMBER(msx_slot_panasonic08_device::write) +{ + if ((offset & 0xc000) == 0x8000 || (offset & 0xc000) == 0x0000) + { + UINT8 bank = m_selected_bank[offset >> 13]; + if (bank >= 0x80 && bank < 0x84) // Are these banks were sram is present? Mirroring? + { + logerror("msx_slot_panasonic08: writing %02x to sram %04x, bank = %02x\n", data, offset & 0x1fff, bank); + m_sram[((bank & 0x01) * 0x2000) + (offset & 0x1fff)] = data; + } + return; + } + + switch (offset) + { + case 0x6000: /* Switched 0x0000-0x1FFF */ + m_selected_bank[0] = data; + map_bank(0); + break; + + case 0x6400: /* Switches 0x2000-0x3FFF */ + m_selected_bank[1] = data; + map_bank(1); + break; + + case 0x6800: /* Switches 0x4000-0x5FFF */ + m_selected_bank[2] = data; + map_bank(2); + break; + + case 0x6c00: /* Switches 0x6000-0x7FFF */ + m_selected_bank[3] = data; + map_bank(3); + break; + + case 0x7000: /* Switches 0x8000-0x9FFF */ + m_selected_bank[4] = data; + map_bank(4); + break; + + case 0x7800: /* Switches 0xA000-0xBFFF */ + m_selected_bank[5] = data; + map_bank(5); + break; + + case 0x7ff9: + m_control = data; + break; + + default: + logerror("msx_slot_panasonic08: Unhandled write %02x to %04x\n", data, offset); + break; + } +} |