From 11fc43aa04f2ed5941cce7b99435d968a968480a Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Tue, 5 Jul 2016 19:12:43 -0400
Subject: [PATCH] Made an attempt to allow the 1540 to talk back to the Vic,
 and to receive interrupts. Also slightly disambiguated debugging logging.

---
 Machines/Commodore/1540/Commodore1540.cpp |  9 ++++
 Machines/Commodore/1540/Commodore1540.hpp | 50 ++++++++++++++++++++++-
 Machines/Commodore/Vic-20/Vic20.hpp       |  2 +-
 3 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/Machines/Commodore/1540/Commodore1540.cpp b/Machines/Commodore/1540/Commodore1540.cpp
index 14ed86671..44379a9d3 100644
--- a/Machines/Commodore/1540/Commodore1540.cpp
+++ b/Machines/Commodore/1540/Commodore1540.cpp
@@ -15,7 +15,9 @@ Machine::Machine()
 {
 	_serialPortVIA.reset(new SerialPortVIA);
 	_serialPort.reset(new SerialPort);
+
 	_serialPort->set_serial_port_via(_serialPortVIA);
+	_serialPortVIA->set_serial_port(_serialPort);
 }
 
 void Machine::set_serial_bus(std::shared_ptr<::Commodore::Serial::Bus> serial_bus)
@@ -55,3 +57,10 @@ void Machine::set_rom(const uint8_t *rom)
 {
 	memcpy(_rom, rom, sizeof(_rom));
 }
+
+#pragma mark - 6522 delegate
+
+void Machine::mos6522_did_change_interrupt_status(void *mos6522)
+{
+	set_irq_line(_serialPortVIA->get_interrupt_line());
+}
diff --git a/Machines/Commodore/1540/Commodore1540.hpp b/Machines/Commodore/1540/Commodore1540.hpp
index 2975edd3e..f47cb3120 100644
--- a/Machines/Commodore/1540/Commodore1540.hpp
+++ b/Machines/Commodore/1540/Commodore1540.hpp
@@ -19,11 +19,55 @@ namespace C1540 {
 class SerialPortVIA: public MOS::MOS6522<SerialPortVIA>, public MOS::MOS6522IRQDelegate {
 	public:
 		using MOS6522IRQDelegate::set_interrupt_status;
+
+		SerialPortVIA() : _portB(0x1f) {}
+
+		uint8_t get_port_input(Port port) {
+			if(port) {
+				return _portB;
+			}
+
+			return 0xff;
+		}
+
+		void set_port_output(Port port, uint8_t value, uint8_t mask) {
+			if(port) {
+				std::shared_ptr<::Commodore::Serial::Port> serialPort = _serialPort.lock();
+				if(serialPort) {
+					serialPort->set_output(::Commodore::Serial::Line::Attention, !(value&0x10));
+					serialPort->set_output(::Commodore::Serial::Line::Clock, !(value&0x08));
+					serialPort->set_output(::Commodore::Serial::Line::Data, !(value&0x02));
+				}
+				printf("1540 serial port VIA port B: %02x\n", value);
+			}
+			else
+				printf("1540 serial port VIA port A: %02x\n", value);
+		}
+
+		void set_serial_line_state(::Commodore::Serial::Line line, bool value) {
+			printf("1540 Serial port line %d: %s\n", line, value ? "on" : "off");
+			switch(line) {
+				default: break;
+				case ::Commodore::Serial::Line::Data:		_portB = (_portB & ~0x01) | (value ? 0 : 0x01);		break;
+				case ::Commodore::Serial::Line::Clock:		_portB = (_portB & ~0x04) | (value ? 0 : 0x04);		break;
+				case ::Commodore::Serial::Line::Attention:	_portB = (_portB & ~0x80) | (value ? 0 : 0x80);		break;
+			}
+		}
+
+		void set_serial_port(std::shared_ptr<::Commodore::Serial::Port> serialPort) {
+			_serialPort = serialPort;
+		}
+
+	private:
+		uint8_t _portB;
+		std::weak_ptr<::Commodore::Serial::Port> _serialPort;
 };
 
 class SerialPort : public ::Commodore::Serial::Port {
 	public:
 		void set_input(::Commodore::Serial::Line line, bool value) {
+			std::shared_ptr<SerialPortVIA> serialPortVIA = _serialPortVIA.lock();
+			if(serialPortVIA) serialPortVIA->set_serial_line_state(line, value);
 		}
 
 		void set_serial_port_via(std::shared_ptr<SerialPortVIA> serialPortVIA) {
@@ -35,7 +79,8 @@ class SerialPort : public ::Commodore::Serial::Port {
 };
 
 class Machine:
-	public CPU6502::Processor<Machine> {
+	public CPU6502::Processor<Machine>,
+	public MOS::MOS6522IRQDelegate::Delegate {
 
 	public:
 		Machine();
@@ -44,6 +89,9 @@ class Machine:
 		void set_rom(const uint8_t *rom);
 		void set_serial_bus(std::shared_ptr<::Commodore::Serial::Bus> serial_bus);
 
+		// to satisfy MOS::MOS6522::Delegate
+		virtual void mos6522_did_change_interrupt_status(void *mos6522);
+
 	private:
 		uint8_t _ram[0x800];
 		uint8_t _rom[0x4000];
diff --git a/Machines/Commodore/Vic-20/Vic20.hpp b/Machines/Commodore/Vic-20/Vic20.hpp
index 386001b61..ca2b55d53 100644
--- a/Machines/Commodore/Vic-20/Vic20.hpp
+++ b/Machines/Commodore/Vic-20/Vic20.hpp
@@ -76,7 +76,7 @@ class UserPortVIA: public MOS::MOS6522<UserPortVIA>, public MOS::MOS6522IRQDeleg
 		}
 
 		void set_serial_line_state(::Commodore::Serial::Line line, bool value) {
-			printf("Serial port line %d: %s\n", line, value ? "on" : "off");
+			printf("VIC Serial port line %d: %s\n", line, value ? "on" : "off");
 			switch(line) {
 				default: break;
 				case ::Commodore::Serial::Line::Data: _portA = (_portA & ~0x02) | (value ? 0 : 0x02);	break;