Introduced a head loading path for 1793 machines.

Components/1770/1770.cpp

@@ -33,7 +33,8 @@ WD1770::WD1770(Personality p) :
 	is_awaiting_marker_value_(false),
 	is_reading_data_(false),
 	delegate_(nullptr),
-	personality_(p)
+	personality_(p),
+	head_is_loaded_(false)
 {
 	set_is_double_density(false);
 	posit_event(Event::Command);
@@ -255,6 +256,12 @@ void WD1770::process_index_hole()
 	{
 		set_motor_on(false);
 	}
+
+	// head unload
+	if(index_hole_count_ == 15 && !status_.busy && has_head_load_line())
+	{
+		set_head_load_request(false);
+	}
 }
 
 //     +------+----------+-------------------------+
@@ -301,6 +308,7 @@ void WD1770::process_index_hole()
 		WAIT_FOR_EVENT(Event::IndexHoleTarget);	\
 		status_.spin_up = true;
 
+
 void WD1770::posit_event(Event new_event_type)
 {
 	if(!(interesting_event_mask_ & (int)new_event_type)) return;
@@ -356,9 +364,24 @@ void WD1770::posit_event(Event new_event_type)
 			status.data_request = false;
 		});
 
-		if((command_&0x08) || get_motor_on() || !has_motor_on_line()) goto test_type1_type;
+		if(!has_motor_on_line() && !has_head_load_line()) goto test_type1_type;
 
-		// Perform spin up.
+		if(has_motor_on_line()) goto begin_type1_spin_up;
+		goto begin_type1_load_head;
+
+	begin_type1_load_head:
+		if(!(command_&0x08))
+		{
+			set_head_load_request(false);
+			goto test_type1_type;
+		}
+		set_head_load_request(true);
+		if(head_is_loaded_) goto test_type1_type;
+		WAIT_FOR_EVENT(Event::HeadLoaded);
+		goto test_type1_type;
+
+	begin_type1_spin_up:
+		if((command_&0x08) || get_motor_on()) goto test_type1_type;
 		SPIN_UP();
 
 	test_type1_type:
@@ -457,8 +480,20 @@ void WD1770::posit_event(Event new_event_type)
 		});
 		distance_into_section_ = 0;
 
-		if((command_&0x08) || get_motor_on() || !has_motor_on_line()) goto test_type2_delay;
+		if((command_&0x08) && has_motor_on_line()) goto test_type2_delay;
+		if(!has_motor_on_line() && !has_head_load_line()) goto test_type2_delay;
 
+		if(has_motor_on_line()) goto begin_type2_spin_up;
+		goto begin_type2_load_head;
+
+	begin_type2_load_head:
+		set_head_load_request(true);
+		if(head_is_loaded_) goto test_type2_delay;
+		WAIT_FOR_EVENT(Event::HeadLoaded);
+		goto test_type2_delay;
+
+	begin_type2_spin_up:
+		if(get_motor_on()) goto test_type2_delay;
 		// Perform spin up.
 		SPIN_UP();
 
@@ -580,3 +615,11 @@ void WD1770::update_status(std::function<void(Status &)> updater)
 	}
 	else updater(status_);
 }
+
+void WD1770::set_head_load_request(bool head_load) {}
+
+void WD1770::set_head_loaded(bool head_loaded)
+{
+	head_is_loaded_ = head_loaded;
+	if(head_loaded) posit_event(Event::HeadLoaded);
+}

Components/1770/1770.hpp

@@ -52,6 +52,10 @@ class WD1770: public Storage::Disk::Controller {
 		};
 		inline void set_delegate(Delegate *delegate)	{	delegate_ = delegate;			}
 
+	protected:
+		virtual void set_head_load_request(bool head_load);
+		void set_head_loaded(bool head_loaded);
+
 	private:
 		Personality personality_;
 		inline bool has_motor_on_line() { return (personality_ != P1793 ) && (personality_ != P1773); }
@@ -102,9 +106,10 @@ class WD1770: public Storage::Disk::Controller {
 			Command			= (1 << 0),	// Indicates receipt of a new command.
 			Token			= (1 << 1),	// Indicates recognition of a new token in the flux stream. Interrogate latest_token_ for details.
 			IndexHole		= (1 << 2),	// Indicates the passing of a physical index hole.
+			HeadLoaded		= (1 << 3),	// Indicates the head has been loaded (1973 only).
 
-			Timer			= (1 << 3),	// Indicates that the delay_time_-powered timer has timed out.
-			IndexHoleTarget	= (1 << 4)	// Indicates that index_hole_count_ has reached index_hole_count_target_.
+			Timer			= (1 << 4),	// Indicates that the delay_time_-powered timer has timed out.
+			IndexHoleTarget	= (1 << 5)	// Indicates that index_hole_count_ has reached index_hole_count_target_.
 		};
 		void posit_event(Event type);
 		int interesting_event_mask_;
@@ -114,7 +119,10 @@ class WD1770: public Storage::Disk::Controller {
 		// ID buffer
 		uint8_t header_[6];
 
-		// output line statuses
+		// 1793 head-loading logic
+		bool head_is_loaded_;
+
+		// delegate
 		Delegate *delegate_;
 
 		// Storage::Disk::Controller

Machines/Oric/Microdisc.cpp

@@ -77,3 +77,10 @@ uint8_t Microdisc::get_data_request_register()
 {
 	return 0x7f | (get_data_request_line() ? 0x00 : 0x80);
 }
+
+void Microdisc::set_head_load_request(bool head_load)
+{
+	set_motor_on(head_load);
+	// TODO: delay
+	set_head_loaded(head_load);
+}

Machines/Oric/Microdisc.hpp

@@ -37,6 +37,7 @@ class Microdisc: public WD::WD1770 {
 		inline int get_paging_flags()					{	return paging_flags_;									}
 
 	private:
+		void set_head_load_request(bool head_load);
 		std::shared_ptr<Storage::Disk::Drive> drives_[4];
 		int selected_drive_;
 		bool irq_enable_;