diff options
Diffstat (limited to 'src/devices/bus/msx/cart/scsi.cpp')
-rw-r--r-- | src/devices/bus/msx/cart/scsi.cpp | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/src/devices/bus/msx/cart/scsi.cpp b/src/devices/bus/msx/cart/scsi.cpp new file mode 100644 index 00000000000..4949fb908fd --- /dev/null +++ b/src/devices/bus/msx/cart/scsi.cpp @@ -0,0 +1,229 @@ +// license:BSD-3-Clause +// copyright-holders:Wilbert Pol +#include "emu.h" +#include "scsi.h" + +#include "bus/nscsi/devices.h" +#include "machine/mb87030.h" +#include "machine/nscsi_bus.h" +#include "machine/wd33c9x.h" + +/* + +Implementation of SCSI interface as it appeared in: +- MSX Computer Club Gouda MSX-SCSI Interface +- ESE MegaSCSI + - Came with SRAM on the cartridge (128/256/512/1024KB SRAM) + + +Other known SCSI(-ish) interfaces: + +ASCII HD Interface (SASI Interface) +B.E.R.T. +HSH SCSI Interface +MAK/Green/Sparrowsoft SCSI Interface +MK SCSI Interface +- Evolved into B.E.R.T. SCSI Interface. + +TODO: +- Fix MegaSCSI mb89352 write operation at 8MHz. + +*/ + +namespace +{ + +class msx_cart_gouda_scsi_device : public device_t, public msx_cart_interface +{ +public: + msx_cart_gouda_scsi_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) + : device_t(mconfig, MSX_CART_GOUDA_SCSI, tag, owner, clock) + , msx_cart_interface(mconfig, *this) + , m_wd33c93a(*this, "scsi:6:wd33c93a") + { } + + virtual std::error_condition initialize_cartridge(std::string &message) override; + +protected: + virtual void device_start() override { } + virtual void device_add_mconfig(machine_config &config) override ATTR_COLD; + +private: + required_device<wd33c93a_device> m_wd33c93a; + + void reset_w(u8 data); +}; + +void msx_cart_gouda_scsi_device::device_add_mconfig(machine_config &config) +{ + NSCSI_BUS(config, "scsi", 0); + NSCSI_CONNECTOR(config, "scsi:0", default_scsi_devices, "harddisk", false); + NSCSI_CONNECTOR(config, "scsi:1", default_scsi_devices, nullptr, false); + NSCSI_CONNECTOR(config, "scsi:2", default_scsi_devices, nullptr, false); + NSCSI_CONNECTOR(config, "scsi:3", default_scsi_devices, nullptr, false); + NSCSI_CONNECTOR(config, "scsi:4", default_scsi_devices, nullptr, false); + NSCSI_CONNECTOR(config, "scsi:5", default_scsi_devices, nullptr, false); + NSCSI_CONNECTOR(config, "scsi:6").option_set("wd33c93a", WD33C93A).clock(10_MHz_XTAL); +} + +std::error_condition msx_cart_gouda_scsi_device::initialize_cartridge(std::string &message) +{ + if (!cart_rom_region()) + { + message = "msx_cart_gouda_scsi_device: Required region 'rom' was not found."; + return image_error::INTERNAL; + } + + if (cart_rom_region()->bytes() < 0x4000) + { + message = "msx_cart_gouda_scsi_device: Region 'rom' has unsupported size."; + return image_error::INVALIDLENGTH; + } + + page(1)->install_rom(0x4000, 0x7fff, cart_rom_region()->base()); + + io_space().install_write_handler(0x34, 0x35, emu::rw_delegate(*m_wd33c93a, FUNC(wd33c93a_device::indir_w))); + io_space().install_read_handler(0x34, 0x35, emu::rw_delegate(*m_wd33c93a, FUNC(wd33c93a_device::indir_r))); + io_space().install_write_handler(0x36, 0x36, emu::rw_delegate(*this, FUNC(msx_cart_gouda_scsi_device::reset_w))); + + return std::error_condition(); +} + +void msx_cart_gouda_scsi_device::reset_w(u8 data) +{ + m_wd33c93a->reset_w(data); +} + + + +class msx_cart_mega_scsi_device : public device_t, public msx_cart_interface +{ +public: + msx_cart_mega_scsi_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) + : device_t(mconfig, MSX_CART_MEGA_SCSI, tag, owner, clock) + , msx_cart_interface(mconfig, *this) + , m_mb89352a(*this, "scsi:7:mb89352a") + , m_srambank(*this, "srambank%u", 0U) + , m_view{ {*this, "view0"}, {*this, "view1"}, {*this, "view2"}, {*this, "view3"} } + , m_bank_mask(0) + { } + + virtual std::error_condition initialize_cartridge(std::string &message) override; + + static constexpr feature_type imperfect_features() { return feature::TIMING; } + +protected: + virtual void device_start() override { } + virtual void device_reset() override ATTR_COLD; + virtual void device_add_mconfig(machine_config &config) override ATTR_COLD; + +private: + static constexpr size_t BANK_SIZE = 0x2000; + + required_device<mb89352_device> m_mb89352a; + memory_bank_array_creator<4> m_srambank; + memory_view m_view[4]; + u8 m_bank_mask; + + template <int Bank> void bank_w(u8 data); +}; + +void msx_cart_mega_scsi_device::device_add_mconfig(machine_config &config) +{ + NSCSI_BUS(config, "scsi", 0); + NSCSI_CONNECTOR(config, "scsi:0", default_scsi_devices, "harddisk", false); + NSCSI_CONNECTOR(config, "scsi:1", default_scsi_devices, nullptr, false); + NSCSI_CONNECTOR(config, "scsi:2", default_scsi_devices, nullptr, false); + NSCSI_CONNECTOR(config, "scsi:3", default_scsi_devices, nullptr, false); + NSCSI_CONNECTOR(config, "scsi:4", default_scsi_devices, nullptr, false); + NSCSI_CONNECTOR(config, "scsi:5", default_scsi_devices, nullptr, false); + NSCSI_CONNECTOR(config, "scsi:6", default_scsi_devices, nullptr, false); + // Input clock is 8MHz according to the schematic. However, clocks below 11MHz cause writes to fail. Reads are fine at 8MHz. + //NSCSI_CONNECTOR(config, "scsi:7").option_set("mb89352a", MB89352).clock(16_MHz_XTAL/2); + NSCSI_CONNECTOR(config, "scsi:7").option_set("mb89352a", MB89352).clock(11'000'000); +} + +void msx_cart_mega_scsi_device::device_reset() +{ + for (int i = 0; i < 4; i++) + { + if (i != 1) + m_view[i].select(0); + m_srambank[i]->set_entry(0); + } +} + +std::error_condition msx_cart_mega_scsi_device::initialize_cartridge(std::string &message) +{ + if (!cart_sram_region()) + { + message = "msx_cart_mega_scsi_device: Required region 'sram' was not found."; + return image_error::INTERNAL; + } + + const u32 sram_size = cart_sram_region()->bytes(); + + if (sram_size != 0x20000 && sram_size != 0x40000 && sram_size != 0x80000 && sram_size != 0x100000) + { + message = "msx_cart_mega_scsi_device: Region 'sram' has unsupported size."; + return image_error::INVALIDLENGTH; + } + + const u16 sram_banks = sram_size / BANK_SIZE; + m_bank_mask = sram_banks - 1; + + for (int i = 0; i < 4; i++) + m_srambank[i]->configure_entries(0, sram_banks, cart_sram_region()->base(), BANK_SIZE); + + page(1)->install_view(0x4000, 0x5fff, m_view[0]); + m_view[0][0].install_read_bank(0x4000, 0x5fff, m_srambank[0]); + m_view[0][1].install_readwrite_bank(0x4000, 0x5fff, m_srambank[0]); + m_view[0][2].install_read_handler(0x4000, 0x4fff, emu::rw_delegate(*m_mb89352a, FUNC(mb89352_device::dma_r))); + m_view[0][2].install_write_handler(0x4000, 0x4fff, emu::rw_delegate(*m_mb89352a, FUNC(mb89352_device::dma_w))); + // mb89352 is mirrored at 5000 - 5fff + for (int addr = 0x5000; addr < 0x6000; addr += 0x10) + m_view[0][2].install_device(addr, addr + 0x0f, *m_mb89352a, &mb89352_device::map); + page(1)->install_read_bank(0x6000, 0x7fff, m_srambank[1]); + page(2)->install_view(0x8000, 0x9fff, m_view[2]); + m_view[2][0].install_read_bank(0x8000, 0x9fff, m_srambank[2]); + m_view[2][1].install_readwrite_bank(0x8000, 0x9fff, m_srambank[2]); + m_view[2][2].install_read_handler(0x8000, 0x8fff, emu::rw_delegate(*m_mb89352a, FUNC(mb89352_device::dma_r))); + m_view[2][2].install_write_handler(0x8000, 0x8fff, emu::rw_delegate(*m_mb89352a, FUNC(mb89352_device::dma_w))); + // mb89352 is mirrored at 9000 - 9fff + for (int addr = 0x9000; addr < 0xa000; addr += 0x10) + m_view[2][2].install_device(addr, addr + 0x0f, *m_mb89352a, &mb89352_device::map); + page(2)->install_view(0xa000, 0xbfff, m_view[3]); + m_view[3][0].install_read_bank(0xa000, 0xbfff, m_srambank[3]); + m_view[3][1].install_readwrite_bank(0xa000, 0xbfff, m_srambank[3]); + m_view[3][2].install_read_handler(0xa000, 0xafff, emu::rw_delegate(*m_mb89352a, FUNC(mb89352_device::dma_r))); + m_view[3][2].install_write_handler(0xa000, 0xafff, emu::rw_delegate(*m_mb89352a, FUNC(mb89352_device::dma_w))); + // mb89352 is mirrored at b000 - bfff + for (int addr = 0xb000; addr < 0xc000; addr += 0x10) + m_view[3][2].install_device(addr, addr + 0x0f, *m_mb89352a, &mb89352_device::map); + + page(1)->install_write_handler(0x6000, 0x67ff, emu::rw_delegate(*this, FUNC(msx_cart_mega_scsi_device::bank_w<0>))); + page(1)->install_write_handler(0x6800, 0x6fff, emu::rw_delegate(*this, FUNC(msx_cart_mega_scsi_device::bank_w<1>))); + page(1)->install_write_handler(0x7000, 0x77ff, emu::rw_delegate(*this, FUNC(msx_cart_mega_scsi_device::bank_w<2>))); + page(1)->install_write_handler(0x7800, 0x7fff, emu::rw_delegate(*this, FUNC(msx_cart_mega_scsi_device::bank_w<3>))); + + return std::error_condition(); +} + +template <int Bank> +void msx_cart_mega_scsi_device::bank_w(u8 data) +{ + // Also writes of $00 and $10 to 7ffe are seen before banking; some kind of banking enable? + m_srambank[Bank]->set_entry(data & m_bank_mask); + if (Bank != 1) + { + int view_to_select = BIT(data, 7) ? 1 : (BIT(data, 6) ? 2 : 0); + + m_view[Bank].select(view_to_select); + } +} + + +} // anonymous namespace + +DEFINE_DEVICE_TYPE_PRIVATE(MSX_CART_GOUDA_SCSI, msx_cart_interface, msx_cart_gouda_scsi_device, "msx_cart_gouda_scsi", "MSX Computer Club Gouda MSX-SCSI Interface") +DEFINE_DEVICE_TYPE_PRIVATE(MSX_CART_MEGA_SCSI, msx_cart_interface, msx_cart_mega_scsi_device, "msx_cart_mega_scsi", "ESE MEGA-SCSI") |