diff options
Diffstat (limited to 'src/devices/bus/odyssey2/rom.cpp')
-rw-r--r-- | src/devices/bus/odyssey2/rom.cpp | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/src/devices/bus/odyssey2/rom.cpp b/src/devices/bus/odyssey2/rom.cpp index 12f8fa9b128..9dcdc480842 100644 --- a/src/devices/bus/odyssey2/rom.cpp +++ b/src/devices/bus/odyssey2/rom.cpp @@ -9,13 +9,32 @@ Standard cartridges emulation, optionally bankswitched up to 8KB. #include "emu.h" #include "rom.h" -DEFINE_DEVICE_TYPE(O2_ROM_STD, o2_rom_device, "o2_rom", "Odyssey 2 Standard Carts") - +namespace { //------------------------------------------------- -// o2_rom_device - constructor +// initialization //------------------------------------------------- +class o2_rom_device : public device_t, public device_o2_cart_interface +{ +public: + o2_rom_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock); + +protected: + virtual void device_start() override; + + virtual void cart_init() override; + + virtual u8 read_rom04(offs_t offset) override; + virtual u8 read_rom0c(offs_t offset) override { return read_rom04(offset + 0x400); } + + virtual void write_p1(u8 data) override { m_bank = data & 3; } + +private: + u32 m_cart_mask = 0; + u8 m_bank = 0; +}; + o2_rom_device::o2_rom_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) : device_t(mconfig, O2_ROM_STD, tag, owner, clock), device_o2_cart_interface(mconfig, *this) @@ -28,7 +47,7 @@ void o2_rom_device::device_start() void o2_rom_device::cart_init() { - m_cart_mask = (1 << (31 - count_leading_zeros(m_rom.bytes()))) - 1; + m_cart_mask = (1 << (31 - count_leading_zeros_32(m_rom_size))) - 1; } @@ -39,5 +58,10 @@ void o2_rom_device::cart_init() u8 o2_rom_device::read_rom04(offs_t offset) { offset = (offset + m_bank * 0x800) & m_cart_mask; - return (offset < m_rom.bytes()) ? m_rom[offset] : 0xff; + return (offset < m_rom_size) ? m_rom[offset] : 0xff; } + +} // anonymous namespace + + +DEFINE_DEVICE_TYPE_PRIVATE(O2_ROM_STD, device_o2_cart_interface, o2_rom_device, "o2_rom", "Odyssey 2 Standard Cartridge") |