Attempted switching back to a square wave for the composite video and otherwise implementing what's necessary to get to that flashing cursor — the 6560 returns its scan line and the timing bits of the 6522 are appearing.

Components/6522/6522.hpp

@@ -16,28 +16,74 @@ namespace MOS {
 
 template <class T> class MOS6522 {
 	public:
-		MOS6522() : _data_direction{0, 0} {}
+		MOS6522() :
+			_data_direction{0, 0},
+			_timer_is_running{false, false}
+		{}
 
 		void set_register(int address, uint8_t value)
 		{
 			printf("6522: %d <- %02x\n", address, value);
-//			switch(address)
+			address &= 0xf;
-//			{
+			switch(address)
-//				case 0x11: _auxiliary_control_register = value;	break;
+			{
-//			}
+				// Timer 1
+				case 0x06:	case 0x04:	_interval_timer_latch[0] = (_interval_timer_latch[0]&0xff00) | value;	break;
+				case 0x05:	case 0x07:
+					_interval_timer_latch[0] = (_interval_timer_latch[0]&0x00ff) | (uint16_t)(value << 8);
+					// TODO: clear interrupt flag
+					if(address == 0x05)
+					{
+						_interval_timer[0] = _interval_timer_latch[0];
+						_timer_is_running[0] = true;
 					}
+				break;
+
+				// Timer 2
+				case 0x08:	_interval_timer_latch[1] = value;	break;
+				case 0x09:
+					// TODO: clear interrupt flag
+					_interval_timer[1] = _interval_timer_latch[1] | (uint16_t)(value << 8);
+					_timer_is_running[1] = true;
+				break;
+
+				case 0x11: _auxiliary_control_register = value;	break;
+			}
+		}
+
 		uint8_t get_register(int address)
 		{
 			printf("6522: %d\n", address);
+			address &= 0xf;
+			switch(address)
+			{
+				// Timer 1
+				case 0x04:
+					// TODO: clear interrupt flag
+				return _interval_timer[0] & 0x00ff;
+				case 0x05:	return _interval_timer[0] >> 8;
+				case 0x06:	return _interval_timer_latch[0] & 0x00ff;
+				case 0x07:	return _interval_timer_latch[0] >> 8;
+			}
+
 			return 0xff;
 		}
 
+		void run_for_cycles(unsigned int number_of_cycles)
+		{
+			_interval_timer[0] -= number_of_cycles;
+			_interval_timer[1] -= number_of_cycles;
+			// TODO: interrupts, potentially reload of the first timer, other status effects
+		}
+
 	private:
-		uint16_t _interval_timers[2];
+		uint16_t _interval_timer[2], _interval_timer_latch[2];
 		uint8_t _shift_register;
-		uint8_t _input_latches[2];
+		uint8_t _input_latch[2];
 		uint8_t _data_direction[2];
 
+		bool _timer_is_running[2];
+
 		uint8_t _interrupt_flag_register, _interrupt_enable_register;
 		uint8_t _peripheral_control_register, _auxiliary_control_register;
 };

Components/6560/6560.cpp

@@ -56,12 +56,14 @@ MOS6560::MOS6560() :
 			"uint iPhase = c & 7u;"
 			"float phaseOffset = 6.283185308 * float(iPhase + 8u) / 8.0;"	// TODO: appropriate phaseOffset
 
-			"return mix(step(1, c) * y, step(2, c) * sin(phase + phaseOffset), amplitude);" // TODO: square wave (step(3.141592654, mod(phase + phaseOffset, 6.283185308))?)
+			// sin(phase + phaseOffset)
+			"return mix(step(1, c) * y, step(2, c) * step(3.141592654, mod(phase + phaseOffset, 6.283185308)) * 2.0, amplitude);" // TODO: square wave (step(3.141592654, mod(phase + phaseOffset, 6.283185308))?)
 		"}");
 }
 
 void MOS6560::set_register(int address, uint8_t value)
 {
+	address &= 0xf;
 	_registers[address] = value;
 	switch(address)
 	{
@@ -114,7 +116,13 @@ void MOS6560::set_register(int address, uint8_t value)
 
 uint8_t MOS6560::get_register(int address)
 {
-	return _registers[address];
+	address &= 0xf;
+	switch(address)
+	{
+		default: return _registers[address];
+		case 0x03: return ((_vertical_counter >> 1) & 0x80) | (_registers[3] & 0x7f);
+		case 0x04: return _vertical_counter & 0xff;
+	}
 }
 
 

Machines/Vic-20/Vic20.cpp

@@ -12,7 +12,9 @@
 
 using namespace Vic20;
 
-Machine::Machine()
+Machine::Machine() :
+	_userPortVIA(new UserPortVIA()),
+	_keyboardVIA(new KeyboardVIA())
 {
 	set_reset_line(true);
 }
@@ -58,10 +60,10 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
 		{
 			_keyboardVIA->set_register(address - 0x9120, *value);
 		}
-
-		// TODO: the 6522
 	}
 
+	_userPortVIA->run_for_cycles(1);
+	_keyboardVIA->run_for_cycles(1);
 	return 1;
 }