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diff --git a/trunk/src/emu/machine/mm74c922.h b/trunk/src/emu/machine/mm74c922.h
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+/**********************************************************************
+
+ MM74C922/MM74C923 16/20-Key Encoder emulation
+
+ Copyright MESS Team.
+ Visit http://mamedev.org for licensing and usage restrictions.
+
+**********************************************************************
+ _____ _____
+ ROW Y1 1 |* \_/ | 18 Vcc
+ ROW Y2 2 | | 17 DATA OUT A
+ ROW Y3 3 | | 16 DATA OUT B
+ ROW Y4 4 | | 15 DATA OUT C
+ OSCILLATOR 5 | MM74C922 | 14 DATA OUT D
+ KEYBOUNCE MASK 6 | | 13 _OUTPUT ENABLE
+ COLUMN X4 7 | | 12 DATA AVAILABLE
+ COLUMN X3 8 | | 11 COLUMN X1
+ GND 9 |_____________| 10 COLUMN X2
+
+ _____ _____
+ ROW Y1 1 |* \_/ | 20 Vcc
+ ROW Y2 2 | | 19 DATA OUT A
+ ROW Y3 3 | | 18 DATA OUT B
+ ROW Y4 4 | | 17 DATA OUT C
+ ROW Y5 5 | MM74C923 | 16 DATA OUT D
+ OSCILLATOR 6 | | 15 DATA OUT E
+ KEYBOUNCE MASK 7 | | 14 _OUTPUT ENABLE
+ COLUMN X4 8 | | 13 DATA AVAILABLE
+ COLUMN X3 9 | | 12 COLUMN X1
+ GND 10 |_____________| 11 COLUMN X2
+
+**********************************************************************/
+
+#pragma once
+
+#ifndef __MM74C922__
+#define __MM74C922__
+
+#include "emu.h"
+
+
+
+//**************************************************************************
+// INTERFACE CONFIGURATION MACROS
+//**************************************************************************
+
+#define MCFG_MM74C922_ADD(_tag, _config) \
+ MCFG_DEVICE_ADD(_tag, MM74C922, 0) \
+ MCFG_DEVICE_CONFIG(_config) \
+ mm74c922_device::static_set_config(*device, 4);
+
+
+#define MCFG_MM74C923_ADD(_tag, _config) \
+ MCFG_DEVICE_ADD(_tag, MM74C923, 0) \
+ MCFG_DEVICE_CONFIG(_config) \
+ mm74c922_device::static_set_config(*device, 5);
+
+
+#define MM74C922_INTERFACE(name) \
+ const mm74c922_interface (name)=
+
+
+#define MM74C923_INTERFACE(name) \
+ const mm74c922_interface (name)=
+
+
+
+//**************************************************************************
+// TYPE DEFINITIONS
+//**************************************************************************
+
+// ======================> mm74c922_interface
+
+struct mm74c922_interface
+{
+ double m_cap_osc;
+ double m_cap_debounce;
+
+ devcb_write_line m_out_da_cb;
+
+ devcb_read8 m_in_x1_cb;
+ devcb_read8 m_in_x2_cb;
+ devcb_read8 m_in_x3_cb;
+ devcb_read8 m_in_x4_cb;
+ devcb_read8 m_in_x5_cb;
+};
+
+
+// ======================> mm74c922_device
+
+class mm74c922_device : public device_t,
+ public mm74c922_interface
+{
+public:
+ // construction/destruction
+ mm74c922_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+
+ // inline configuration helpers
+ static void static_set_config(device_t &device, int max_y);
+
+ UINT8 data_out_r();
+
+protected:
+ // device-level overrides
+ virtual void device_config_complete();
+ virtual void device_start();
+ virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr);
+
+private:
+ inline void change_output_lines();
+ inline void clock_scan_counters();
+ inline void detect_keypress();
+
+ int m_max_y;
+
+ devcb_resolved_write_line m_out_da_func;
+ devcb_resolved_read8 m_in_x_func[5];
+
+ int m_inhibit; // scan counter clock inhibit
+ int m_x; // currently scanned column
+ int m_y; // latched row
+
+ UINT8 m_data; // data latch
+
+ int m_da; // data available flag
+ int m_next_da; // next value of data available flag
+
+ // timers
+ emu_timer *m_scan_timer; // keyboard scan timer
+};
+
+
+// device type definition
+extern const device_type MM74C922;
+extern const device_type MM74C923;
+
+
+
+#endif