// license:BSD-3-Clause // copyright-holders:Nigel Barnes /*************************************************************************** Master Smart Cartridge emulation ***************************************************************************/ #include "emu.h" #include "msc.h" namespace { class bbc_msc_device : public device_t, public device_bbc_cart_interface { public: bbc_msc_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, BBC_MSC, tag, owner, clock) , device_bbc_cart_interface(mconfig, *this) , m_button(*this, "BUTTON") { } DECLARE_INPUT_CHANGED_MEMBER(activate); protected: // device_t overrides virtual void device_start() override ATTR_COLD { } virtual ioport_constructor device_input_ports() const override ATTR_COLD; // bbc_cart_interface overrides virtual uint8_t read(offs_t offset, int infc, int infd, int romqa, int oe, int oe2) override; virtual void write(offs_t offset, uint8_t data, int infc, int infd, int romqa, int oe, int oe2) override; private: required_ioport m_button; }; //------------------------------------------------- // input_ports - device-specific input ports //------------------------------------------------- INPUT_PORTS_START(msc) PORT_START("BUTTON") PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_BUTTON1) PORT_NAME("Activate") PORT_CODE(KEYCODE_HOME) PORT_CHANGED_MEMBER(DEVICE_SELF, FUNC(bbc_msc_device::activate), 0) INPUT_PORTS_END ioport_constructor bbc_msc_device::device_input_ports() const { return INPUT_PORTS_NAME(msc); } //------------------------------------------------- // read - cartridge data read //------------------------------------------------- uint8_t bbc_msc_device::read(offs_t offset, int infc, int infd, int romqa, int oe, int oe2) { uint8_t data = 0xff; if (oe & !romqa) { if (offset & 0x2000) { data = m_ram[offset & 0x7ff]; } else { data = m_rom[(offset & 0x1fff) | (m_button->read() << 13)]; } } return data; } //------------------------------------------------- // write - cartridge data write //------------------------------------------------- void bbc_msc_device::write(offs_t offset, uint8_t data, int infc, int infd, int romqa, int oe, int oe2) { if (oe & !romqa) { if (offset & 0x2000) { m_ram[offset & 0x7ff] = data; } } } INPUT_CHANGED_MEMBER(bbc_msc_device::activate) { m_slot->irq_w(!newval); } } // anonymous namespace DEFINE_DEVICE_TYPE_PRIVATE(BBC_MSC, device_bbc_cart_interface, bbc_msc_device, "bbc_msc", "Master Smart Cartridge")