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Diffstat (limited to 'src/devices/bus/odyssey2/chess.cpp')
-rw-r--r--src/devices/bus/odyssey2/chess.cpp120
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")