// license:BSD-3-Clause // copyright-holders:Nigel Barnes /********************************************************************** Memex B20 20K RAM expansion **********************************************************************/ #ifndef MAME_BUS_BBC_INTERNAL_MEMEX_H #define MAME_BUS_BBC_INTERNAL_MEMEX_H #include "internal.h" //************************************************************************** // TYPE DEFINITIONS //************************************************************************** class bbc_memexb20_device : public device_t, public device_bbc_internal_interface { public: // construction/destruction bbc_memexb20_device(const machine_config &mconfig, const char *tag, device_t *owner, const XTAL &clock); protected: // device-level overrides virtual void device_start() override; // optional information overrides virtual const tiny_rom_entry *device_rom_region() const override; virtual bool overrides_ram() override { return true; } virtual uint8_t ram_r(offs_t offset) override; virtual void ram_w(offs_t offset, uint8_t data) override; private: void enable_w(uint8_t data); void disable_w(uint8_t data); bool m_shadow; std::unique_ptr m_ram; }; // device type definition DECLARE_DEVICE_TYPE(BBC_MEMEXB20, bbc_memexb20_device); #endif /* MAME_BUS_BBC_INTERNAL_MEMEX_H */