Start to consolidate relationship around push.

Machines/Commodore/1540/Implementation/C1540.cpp

@@ -109,10 +109,7 @@ Cycles MachineBase::perform(const AddressT address, CPU::MOS6502Mk2::data_t<oper
 
 void Machine::run_for(const Cycles cycles) {
 	m6502_.run_for(cycles);
-
-	const bool drive_motor = drive_VIA_port_handler_.motor_enabled();
-	get_drive().set_motor_on(drive_motor);
-	if(drive_motor) {
+	if(get_drive().get_motor_on()) {
 		Storage::Disk::Controller::run_for(cycles);
 	}
 }
@@ -150,15 +147,16 @@ void MachineBase::process_input_bit(const int value) {
 	} else {
 		drive_VIA_port_handler_.set_sync_detected(false);
 	}
-	bit_window_offset_++;
+	++bit_window_offset_;
 	if(bit_window_offset_ == 8) {
 		drive_VIA_port_handler_.set_data_input(uint8_t(shift_register_));
 		bit_window_offset_ = 0;
-		if(drive_VIA_port_handler_.should_set_overflow()) {
+		if(set_cpu_overflow_) {
 			m6502_.set<CPU::MOS6502Mk2::Line::Overflow>(true);
 		}
+	} else {
+		m6502_.set<CPU::MOS6502Mk2::Line::Overflow>(false);
 	}
-	else m6502_.set<CPU::MOS6502Mk2::Line::Overflow>(false);
 }
 
 // the 1540 does not recognise index holes
@@ -174,6 +172,21 @@ void MachineBase::drive_via_did_set_data_density(DriveVIA &, const int density)
 	set_expected_bit_length(Storage::Encodings::CommodoreGCR::length_of_a_bit_in_time_zone(unsigned(density)));
 }
 
+void MachineBase::drive_via_did_set_drive_motor(DriveVIA &, const bool enabled) {
+	get_drive().set_motor_on(enabled);
+}
+
+void MachineBase::drive_via_did_set_write_mode(DriveVIA &, bool) {
+	// TODO.
+}
+
+void MachineBase::drive_via_should_set_cpu_overflow(DriveVIA &, const bool overflow) {
+	set_cpu_overflow_ = overflow;
+	if(!overflow) {
+		m6502_.set<CPU::MOS6502Mk2::Line::Overflow>(false);
+	}
+}
+
 // MARK: - SerialPortVIA
 
 template <MOS::MOS6522::Port port>
@@ -200,13 +213,17 @@ void SerialPortVIA::set_serial_line_state(
 	const bool value,
 	MOS::MOS6522::MOS6522<SerialPortVIA> &via
 ) {
+	const auto set = [&](const uint8_t mask) {
+		port_b_ = (port_b_ & ~mask) | (value ? 0x00 : mask);
+	};
+
 	switch(line) {
 		default: break;
-		case ::Commodore::Serial::Line::Data:		port_b_ = (port_b_ & ~0x01) | (value ? 0x00 : 0x01);		break;
-		case ::Commodore::Serial::Line::Clock:		port_b_ = (port_b_ & ~0x04) | (value ? 0x00 : 0x04);		break;
+		case ::Commodore::Serial::Line::Data:		set(0x01);		break;
+		case ::Commodore::Serial::Line::Clock:		set(0x04);		break;
 		case ::Commodore::Serial::Line::Attention:
+			set(0x80);
 			attention_level_input_ = !value;
-			port_b_ = (port_b_ & ~0x80) | (value ? 0x00 : 0x80);
 			via.set_control_line_input<MOS::MOS6522::Port::A, MOS::MOS6522::Line::One>(!value);
 			update_data_line();
 		break;
@@ -249,24 +266,23 @@ void DriveVIA::set_data_input(const uint8_t value) {
 	port_a_ = value;
 }
 
-bool DriveVIA::should_set_overflow() {
-	return should_set_overflow_;
-}
-
-bool DriveVIA::motor_enabled() {
-	return drive_motor_;
-}
-
 template <MOS::MOS6522::Port port, MOS::MOS6522::Line line>
 void DriveVIA::set_control_line_output(const bool value) {
 	if(port == MOS::MOS6522::Port::A && line == MOS::MOS6522::Line::Two) {
-		should_set_overflow_ = value;
+		if(set_cpu_overflow_ != value) {
+			set_cpu_overflow_ = value;
+			if(delegate_) {
+				delegate_->drive_via_should_set_cpu_overflow(*this, set_cpu_overflow_);
+			}
+		}
 	}
 
 	if(port == MOS::MOS6522::Port::B && line == MOS::MOS6522::Line::Two) {
-		// TODO: 0 = write, 1 = read.
-		if(!value) {
-			printf("NOT IMPLEMENTED: write mode\n");
+		if(value != write_mode_) {
+			write_mode_ = !value;
+			if(delegate_) {
+				delegate_->drive_via_did_set_write_mode(*this, write_mode_);
+			}
 		}
 	}
 }
@@ -275,7 +291,13 @@ template <>
 void DriveVIA::set_port_output<MOS::MOS6522::Port::B>(const uint8_t value, uint8_t) {
 	if(previous_port_b_output_ != value) {
 		// Record drive motor state.
-		drive_motor_ = value&4;
+		const bool new_drive_motor = value & 4;
+		if(new_drive_motor != drive_motor_) {
+			drive_motor_ = new_drive_motor;
+			if(delegate_) {
+				delegate_->drive_via_did_set_drive_motor(*this, drive_motor_);
+			}
+		}
 
 		// Check for a head step.
 		const int step_difference = ((value&3) - (previous_port_b_output_&3))&3;

Machines/Commodore/1540/Implementation/C1540Base.hpp

@@ -82,6 +82,9 @@ public:
 	struct Delegate {
 		virtual void drive_via_did_step_head(DriveVIA &, int direction) = 0;
 		virtual void drive_via_did_set_data_density(DriveVIA &, int density) = 0;
+		virtual void drive_via_did_set_drive_motor(DriveVIA &, bool enabled) = 0;
+		virtual void drive_via_did_set_write_mode(DriveVIA &, bool write) = 0;
+		virtual void drive_via_should_set_cpu_overflow(DriveVIA &, bool overflow) = 0;
 	};
 	void set_delegate(Delegate *);
 
@@ -91,8 +94,6 @@ public:
 	void set_sync_detected(bool);
 	void set_data_input(uint8_t);
 	void set_is_read_only(bool);
-	bool should_set_overflow();
-	bool motor_enabled();
 
 	template <MOS::MOS6522::Port, MOS::MOS6522::Line>
 	void set_control_line_output(bool value);
@@ -104,8 +105,11 @@ public:
 
 private:
 	uint8_t port_b_ = 0xff, port_a_ = 0xff;
-	bool should_set_overflow_ = false;
+
+	bool set_cpu_overflow_ = false;
 	bool drive_motor_ = false;
+	bool write_mode_ = false;
+
 	uint8_t previous_port_b_output_ = 0;
 	Delegate *delegate_ = nullptr;
 	Activity::Observer *observer_ = nullptr;
@@ -144,8 +148,11 @@ protected:
 	void mos6522_did_change_interrupt_status(void *mos6522) override;
 
 	// to satisfy DriveVIA::Delegate
-	void drive_via_did_step_head(DriveVIA &, int direction) override;
-	void drive_via_did_set_data_density(DriveVIA &, int density) override;
+	void drive_via_did_step_head(DriveVIA &, int) override;
+	void drive_via_did_set_data_density(DriveVIA &, int) override;
+	void drive_via_did_set_drive_motor(DriveVIA &, bool) override;
+	void drive_via_did_set_write_mode(DriveVIA &, bool) override;
+	void drive_via_should_set_cpu_overflow(DriveVIA &, bool) override;
 
 	struct M6502Traits {
 		static constexpr auto uses_ready_line = false;
@@ -164,6 +171,7 @@ protected:
 	MOS::MOS6522::MOS6522<DriveVIA> drive_VIA_;
 	MOS::MOS6522::MOS6522<SerialPortVIA> serial_port_VIA_;
 
+	bool set_cpu_overflow_ = false;
 	int shift_register_ = 0, bit_window_offset_;
 	void process_input_bit(int value) override;
 	void process_index_hole() override;