diff options
Diffstat (limited to 'src/devices/bus/odyssey2/chess.cpp')
-rw-r--r-- | src/devices/bus/odyssey2/chess.cpp | 120 |
1 files changed, 103 insertions, 17 deletions
diff --git a/src/devices/bus/odyssey2/chess.cpp b/src/devices/bus/odyssey2/chess.cpp index 44890a394ce..ae8efb14ce8 100644 --- a/src/devices/bus/odyssey2/chess.cpp +++ b/src/devices/bus/odyssey2/chess.cpp @@ -1,43 +1,120 @@ // license:BSD-3-Clause -// copyright-holders:Fabio Priuli -/*********************************************************************************************************** +// copyright-holders:hap +/****************************************************************************** +Videopac C7010 Chess Module emulation - Videopac Chess Module emulation +The chess engine is Wim Rens's Gambiet, evidently based on the 1980 version. - TODO: - - this code is just a stub... hence, almost everything is still to do! - - ***********************************************************************************************************/ +Hardware notes: +- NSC800 (Z80-compatible) @ 4.43MHz +- 8KB ROM, 2KB RAM +******************************************************************************/ #include "emu.h" #include "chess.h" +#include "cpu/z80/nsc800.h" +#include "machine/gen_latch.h" + +namespace { //------------------------------------------------- -// o2_chess_device - constructor +// initialization //------------------------------------------------- -DEFINE_DEVICE_TYPE(O2_ROM_CHESS, o2_chess_device, "o2_chess", "Odyssey 2 Videopac Chess Module") +class o2_chess_device : public device_t, public device_o2_cart_interface +{ +public: + o2_chess_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock); + +protected: + virtual void device_start() override ATTR_COLD; + virtual void device_add_mconfig(machine_config &config) override ATTR_COLD; + + virtual void cart_init() override; + + virtual u8 read_rom04(offs_t offset) override { return m_rom[offset]; } + virtual u8 read_rom0c(offs_t offset) override { return m_rom[offset + 0x400]; } + + virtual void write_p1(u8 data) override; + virtual void io_write(offs_t offset, u8 data) override; + virtual u8 io_read(offs_t offset) override; + +private: + required_device<cpu_device> m_maincpu; + required_device_array<generic_latch_8_device, 2> m_latch; + + u8 m_control = 0; + u8 internal_rom_r(offs_t offset) { return m_exrom[offset]; } -o2_chess_device::o2_chess_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) - : o2_rom_device(mconfig, O2_ROM_CHESS, tag, owner, clock) - , m_cpu(*this, "subcpu") + void chess_io(address_map &map) ATTR_COLD; + void chess_mem(address_map &map) ATTR_COLD; +}; + +o2_chess_device::o2_chess_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) : + device_t(mconfig, O2_ROM_CHESS, tag, owner, clock), + device_o2_cart_interface(mconfig, *this), + m_maincpu(*this, "maincpu"), + m_latch(*this, "latch%u", 0) +{ } + +void o2_chess_device::device_start() +{ + save_item(NAME(m_control)); +} + +void o2_chess_device::cart_init() { + if (m_rom_size != 0x800 || m_exrom_size != 0x2000) + fatalerror("o2_chess_device: Wrong ROM region size\n"); } +//------------------------------------------------- +// mapper specific handlers +//------------------------------------------------- + +void o2_chess_device::write_p1(u8 data) +{ + // P11: reset + m_maincpu->set_input_line(INPUT_LINE_RESET, (data & 2) ? CLEAR_LINE : ASSERT_LINE); + + // P10,P14: must be low to access latches + m_control = data; +} + +u8 o2_chess_device::io_read(offs_t offset) +{ + if ((offset & 0xa0) == 0xa0 && (m_control & 0x11) == 0) + return m_latch[0]->read(); + else + return 0xff; +} + +void o2_chess_device::io_write(offs_t offset, u8 data) +{ + if (offset & 0x80 && (m_control & 0x11) == 0) + m_latch[1]->write(data); +} + + +//------------------------------------------------- +// address maps +//------------------------------------------------- + void o2_chess_device::chess_mem(address_map &map) { - map(0x0000, 0x07ff).r(FUNC(o2_chess_device::read_rom04)); + map(0x0000, 0x1fff).r(FUNC(o2_chess_device::internal_rom_r)); + map(0xe000, 0xe7ff).mirror(0x1800).ram(); } void o2_chess_device::chess_io(address_map &map) { - map.unmap_value_high(); map.global_mask(0xff); + map(0x00, 0x00).mirror(0xff).r(m_latch[1], FUNC(generic_latch_8_device::read)).w(m_latch[0], FUNC(generic_latch_8_device::write)); } @@ -47,7 +124,16 @@ void o2_chess_device::chess_io(address_map &map) void o2_chess_device::device_add_mconfig(machine_config &config) { - NSC800(config, m_cpu, XTAL(4'000'000)); - m_cpu->set_addrmap(AS_PROGRAM, &o2_chess_device::chess_mem); - m_cpu->set_addrmap(AS_IO, &o2_chess_device::chess_io); + // basic machine hardware + NSC800(config, m_maincpu, 4.433619_MHz_XTAL); + m_maincpu->set_addrmap(AS_PROGRAM, &o2_chess_device::chess_mem); + m_maincpu->set_addrmap(AS_IO, &o2_chess_device::chess_io); + + GENERIC_LATCH_8(config, m_latch[0]); + GENERIC_LATCH_8(config, m_latch[1]); } + +} // anonymous namespace + + +DEFINE_DEVICE_TYPE_PRIVATE(O2_ROM_CHESS, device_o2_cart_interface, o2_chess_device, "o2_chess", "Videopac C7010 Cartridge") |