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// 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, uint32_t 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<uint8_t[]> m_ram;
};
// device type definition
DECLARE_DEVICE_TYPE(BBC_MEMEXB20, bbc_memexb20_device);
#endif /* MAME_BUS_BBC_INTERNAL_MEMEX_H */
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