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Diffstat (limited to 'src/devices/bus/msx/ctrl/magickey.cpp')
-rw-r--r--src/devices/bus/msx/ctrl/magickey.cpp53
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diff --git a/src/devices/bus/msx/ctrl/magickey.cpp b/src/devices/bus/msx/ctrl/magickey.cpp
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+++ b/src/devices/bus/msx/ctrl/magickey.cpp
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+// license:BSD-3-Clause
+// copyright-holders:hap
+/**********************************************************************
+
+Sony Magic Key emulation
+
+It's a dongle that enables a cheat menu on some games published by Sony
+when inserted into port B. It was a lottery prize from a Japanese MSX
+magazine, not sold separately.
+
+The dongle ties pin 1/2 (up/down) to pin 8 (strobe).
+
+Note that this cheat menu can also be accessed with an FM Towns pad.
+
+**********************************************************************/
+
+#include "emu.h"
+#include "magickey.h"
+
+
+namespace {
+
+class msx_magickey_device : public device_t, public device_msx_general_purpose_port_interface
+{
+public:
+ msx_magickey_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock);
+
+ virtual u8 read() override { return m_pin8_state ? 0xff : 0xfc; }
+ virtual void pin_8_w(int state) override { m_pin8_state = state; }
+
+protected:
+ virtual void device_start() override ATTR_COLD;
+
+private:
+ u8 m_pin8_state = 0;
+};
+
+
+msx_magickey_device::msx_magickey_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock)
+ : device_t(mconfig, MSX_MAGICKEY, tag, owner, clock)
+ , device_msx_general_purpose_port_interface(mconfig, *this)
+{
+}
+
+void msx_magickey_device::device_start()
+{
+ save_item(NAME(m_pin8_state));
+}
+
+} // anonymous namespace
+
+
+DEFINE_DEVICE_TYPE_PRIVATE(MSX_MAGICKEY, device_msx_general_purpose_port_interface, msx_magickey_device, "msx_magickey", "Sony Magic Key Dongle")