CLK/Machines/Commodore/Vic-20/Vic20.cpp

//
//  Vic20.cpp
//  Clock Signal
//
//  Created by Thomas Harte on 04/06/2016.
//  Copyright © 2016 Thomas Harte. All rights reserved.
//

#include "Vic20.hpp"

#include <algorithm>
#include "../../../Storage/Tape/Formats/TapePRG.hpp"
#include "../../../StaticAnalyser/StaticAnalyser.hpp"

using namespace Commodore::Vic20;

Machine::Machine() :
	rom_(nullptr),
	is_running_at_zero_cost_(false),
	tape_(1022727)
{
	// create 6522s, serial port and bus
	user_port_via_.reset(new UserPortVIA);
	keyboard_via_.reset(new KeyboardVIA);
	serial_port_.reset(new SerialPort);
	serial_bus_.reset(new ::Commodore::Serial::Bus);

	// wire up the serial bus and serial port
	Commodore::Serial::AttachPortAndBus(serial_port_, serial_bus_);

	// wire up 6522s and serial port
	user_port_via_->set_serial_port(serial_port_);
	keyboard_via_->set_serial_port(serial_port_);
	serial_port_->set_user_port_via(user_port_via_);

	// wire up the 6522s, tape and machine
	user_port_via_->set_interrupt_delegate(this);
	keyboard_via_->set_interrupt_delegate(this);
	tape_.set_delegate(this);

	// establish the memory maps
	set_memory_size(MemorySize::Default);

	// set the NTSC clock rate
	set_region(NTSC);
//	_debugPort.reset(new ::Commodore::Serial::DebugPort);
//	_debugPort->set_serial_bus(serial_bus_);
//	serial_bus_->add_port(_debugPort);
}

void Machine::set_memory_size(MemorySize size)
{
	memset(processor_read_memory_map_, 0, sizeof(processor_read_memory_map_));
	memset(processor_write_memory_map_, 0, sizeof(processor_write_memory_map_));

	switch(size)
	{
		default: break;
		case ThreeKB:
			write_to_map(processor_read_memory_map_, expansion_ram_, 0x0000, 0x1000);
			write_to_map(processor_write_memory_map_, expansion_ram_, 0x0000, 0x1000);
		break;
		case ThirtyTwoKB:
			write_to_map(processor_read_memory_map_, expansion_ram_, 0x0000, 0x8000);
			write_to_map(processor_write_memory_map_, expansion_ram_, 0x0000, 0x8000);
		break;
	}

	// install the system ROMs and VIC-visible memory
	write_to_map(processor_read_memory_map_, user_basic_memory_, 0x0000, sizeof(user_basic_memory_));
	write_to_map(processor_read_memory_map_, screen_memory_, 0x1000, sizeof(screen_memory_));
	write_to_map(processor_read_memory_map_, colour_memory_, 0x9400, sizeof(colour_memory_));
	write_to_map(processor_read_memory_map_, character_rom_, 0x8000, sizeof(character_rom_));
	write_to_map(processor_read_memory_map_, basic_rom_, 0xc000, sizeof(basic_rom_));
	write_to_map(processor_read_memory_map_, kernel_rom_, 0xe000, sizeof(kernel_rom_));

	write_to_map(processor_write_memory_map_, user_basic_memory_, 0x0000, sizeof(user_basic_memory_));
	write_to_map(processor_write_memory_map_, screen_memory_, 0x1000, sizeof(screen_memory_));
	write_to_map(processor_write_memory_map_, colour_memory_, 0x9400, sizeof(colour_memory_));

	// install the inserted ROM if there is one
	if(rom_)
	{
		write_to_map(processor_read_memory_map_, rom_, rom_address_, rom_length_);
	}
}

void Machine::write_to_map(uint8_t **map, uint8_t *area, uint16_t address, uint16_t length)
{
	address >>= 10;
	length >>= 10;
	while(length--)
	{
		map[address] = area;
		area += 0x400;
		address++;
	}
}

Machine::~Machine()
{
	delete[] rom_;
}

unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uint16_t address, uint8_t *value)
{
//	static int logCount = 0;
//	if(operation == CPU6502::BusOperation::ReadOpcode && address == 0xf957) logCount = 500;
//	if(operation == CPU6502::BusOperation::ReadOpcode && logCount) {
//		logCount--;
//		printf("%04x\n", address);
//	}

//	if(operation == CPU6502::BusOperation::Write && (address >= 0x033C && address < 0x033C + 192))
//	{
//		printf("\n[%04x] <- %02x\n", address, *value);
//	}

	// run the phase-1 part of this cycle, in which the VIC accesses memory
	if(!is_running_at_zero_cost_) mos6560_->run_for_cycles(1);

	// run the phase-2 part of the cycle, which is whatever the 6502 said it should be
	if(isReadOperation(operation))
	{
		uint8_t result = processor_read_memory_map_[address >> 10] ? processor_read_memory_map_[address >> 10][address & 0x3ff] : 0xff;
		if((address&0xfc00) == 0x9000)
		{
			if((address&0xff00) == 0x9000)	result &= mos6560_->get_register(address);
			if((address&0xfc10) == 0x9010)	result &= user_port_via_->get_register(address);
			if((address&0xfc20) == 0x9020)	result &= keyboard_via_->get_register(address);
		}
		*value = result;

		// This combined with the stuff below constitutes the fast tape hack. Performed here: if the
		// PC hits the start of the loop that just waits for an interesting tape interrupt to have
		// occurred then skip both 6522s and the tape ahead to the next interrupt without any further
		// CPU or 6560 costs.
		if(use_fast_tape_hack_ && tape_.has_tape() && address == 0xf92f && operation == CPU6502::BusOperation::ReadOpcode)
		{
			while(!user_port_via_->get_interrupt_line() && !keyboard_via_->get_interrupt_line() && !tape_.get_tape()->is_at_end())
			{
				user_port_via_->run_for_cycles(1);
				keyboard_via_->run_for_cycles(1);
				tape_.run_for_cycles(1);
			}
		}
	}
	else
	{
		uint8_t *ram = processor_write_memory_map_[address >> 10];
		if(ram) ram[address & 0x3ff] = *value;
		if((address&0xfc00) == 0x9000)
		{
			if((address&0xff00) == 0x9000)	mos6560_->set_register(address, *value);
			if((address&0xfc10) == 0x9010)	user_port_via_->set_register(address, *value);
			if((address&0xfc20) == 0x9020)	keyboard_via_->set_register(address, *value);
		}
	}

	user_port_via_->run_for_cycles(1);
	keyboard_via_->run_for_cycles(1);
	if(typer_ && operation == CPU6502::BusOperation::ReadOpcode && address == 0xEB1E)
	{
		if(!typer_->type_next_character())
		{
			clear_all_keys();
			typer_.reset();
		}
	}
	tape_.run_for_cycles(1);
	if(c1540_) c1540_->run_for_cycles(1);

	// If using fast tape then:
	//	if the PC hits 0xf98e, the ROM's tape loading routine, then begin zero cost processing;
	//	if the PC heads into RAM
	//
	// Where 'zero cost processing' is taken to be taking the 6560 off the bus (because I know it's
	// expensive, and not relevant) then running the tape, the CPU and both 6522s as usual but not
	// counting cycles towards the processing budget. So the limit is the host machine.
	//
	// Note the additional test above for PC hitting 0xf92f, which is a loop in the ROM that waits
	// for an interesting interrupt. Up there the fast tape hack goes even further in also cutting
	// the CPU out of the action.
	if(use_fast_tape_hack_ && tape_.has_tape())
	{
		if(address == 0xf98e && operation == CPU6502::BusOperation::ReadOpcode)
		{
			is_running_at_zero_cost_ = true;
			set_clock_is_unlimited(true);
		}
		if(
			(address < 0xe000 && operation == CPU6502::BusOperation::ReadOpcode) ||
			tape_.get_tape()->is_at_end()
		)
		{
			is_running_at_zero_cost_ = false;
			set_clock_is_unlimited(false);
		}
	}

	return 1;
}

#pragma mark - 6522 delegate

void Machine::mos6522_did_change_interrupt_status(void *mos6522)
{
	set_nmi_line(user_port_via_->get_interrupt_line());
	set_irq_line(keyboard_via_->get_interrupt_line());
}

#pragma mark - Setup

void Machine::set_region(Commodore::Vic20::Region region)
{
	region_ = region;
	switch(region)
	{
		case PAL:
			set_clock_rate(1108404);
			if(mos6560_)
			{
				mos6560_->set_output_mode(MOS::MOS6560<Commodore::Vic20::Vic6560>::OutputMode::PAL);
				mos6560_->set_clock_rate(1108404);
			}
		break;
		case NTSC:
			set_clock_rate(1022727);
			if(mos6560_)
			{
				mos6560_->set_output_mode(MOS::MOS6560<Commodore::Vic20::Vic6560>::OutputMode::NTSC);
				mos6560_->set_clock_rate(1022727);
			}
		break;
	}
}

void Machine::setup_output(float aspect_ratio)
{
	mos6560_.reset(new Vic6560());
	mos6560_->get_speaker()->set_high_frequency_cut_off(1600);	// There is a 1.6Khz low-pass filter in the Vic-20.
	set_region(region_);

	memset(mos6560_->video_memory_map, 0, sizeof(mos6560_->video_memory_map));
	write_to_map(mos6560_->video_memory_map, character_rom_, 0x0000, sizeof(character_rom_));
	write_to_map(mos6560_->video_memory_map, user_basic_memory_, 0x2000, sizeof(user_basic_memory_));
	write_to_map(mos6560_->video_memory_map, screen_memory_, 0x3000, sizeof(screen_memory_));
	mos6560_->colour_memory = colour_memory_;
}

void Machine::close_output()
{
	mos6560_ = nullptr;
}

void Machine::set_rom(ROMSlot slot, size_t length, const uint8_t *data)
{
	uint8_t *target = nullptr;
	size_t max_length = 0x2000;
	switch(slot)
	{
		case Kernel:		target = kernel_rom_;								break;
		case Characters:	target = character_rom_;	max_length = 0x1000;	break;
		case BASIC:			target = basic_rom_;								break;
		case Drive:
			drive_rom_.reset(new uint8_t[length]);
			memcpy(drive_rom_.get(), data, length);
			install_disk_rom();
		return;
	}

	if(target)
	{
		size_t length_to_copy = std::min(max_length, length);
		memcpy(target, data, length_to_copy);
	}
}

//void Machine::set_prg(const char *file_name, size_t length, const uint8_t *data)
//{
//	if(length > 2)
//	{
//		_rom_address = (uint16_t)(data[0] | (data[1] << 8));
//		_rom_length = (uint16_t)(length - 2);
//
//		// install in the ROM area if this looks like a ROM; otherwise put on tape and throw into that mechanism
//		if(_rom_address == 0xa000)
//		{
//			_rom = new uint8_t[0x2000];
//			memcpy(_rom, &data[2], length - 2);
//			write_to_map(processor_read_memory_map_, _rom, _rom_address, 0x2000);
//		}
//		else
//		{
//			set_tape(std::shared_ptr<Storage::Tape::Tape>(new Storage::Tape::PRG(file_name)));
//		}
//	}
//}

#pragma mar - Tape

void Machine::configure_as_target(const StaticAnalyser::Target &target)
{
	if(target.tapes.size())
	{
		tape_.set_tape(target.tapes.front());
	}

	if(target.disks.size())
	{
		// construct the 1540
		c1540_.reset(new ::Commodore::C1540::Machine);

		// attach it to the serial bus
		c1540_->set_serial_bus(serial_bus_);

		// hand it the disk
		c1540_->set_disk(target.disks.front());

		// install the ROM if it was previously set
		install_disk_rom();
	}

	if(target.cartridges.size())
	{
		rom_address_ = 0xa000;
		std::vector<uint8_t> rom_image = target.cartridges.front()->get_segments().front().data;
		rom_length_ = (uint16_t)(rom_image.size());

		rom_ = new uint8_t[0x2000];
		memcpy(rom_, rom_image.data(), rom_image.size());
		write_to_map(processor_read_memory_map_, rom_, rom_address_, 0x2000);
	}

	if(should_automatically_load_media_)
	{
		if(target.loadingCommand.length())	// TODO: and automatic loading option enabled
		{
			set_typer_for_string(target.loadingCommand.c_str());
		}

		switch(target.vic20.memory_model)
		{
			case StaticAnalyser::Vic20MemoryModel::Unexpanded:
				set_memory_size(Default);
			break;
			case StaticAnalyser::Vic20MemoryModel::EightKB:
				set_memory_size(ThreeKB);
			break;
			case StaticAnalyser::Vic20MemoryModel::ThirtyTwoKB:
				set_memory_size(ThirtyTwoKB);
			break;
		}
	}
}

void Machine::tape_did_change_input(Storage::Tape::BinaryTapePlayer *tape)
{
	keyboard_via_->set_control_line_input(KeyboardVIA::Port::A, KeyboardVIA::Line::One, tape->get_input());
}

#pragma mark - Disc

void Machine::install_disk_rom()
{
	if(drive_rom_ && c1540_)
	{
		c1540_->set_rom(drive_rom_.get());
		c1540_->run_for_cycles(2000000);
		drive_rom_.reset();
	}
}

#pragma mark - UserPortVIA

uint8_t UserPortVIA::get_port_input(Port port)
{
	if(!port)
	{
		return port_a_;	// TODO: bit 6 should be high if there is no tape, low otherwise
	}
	return 0xff;
}

void UserPortVIA::set_control_line_output(Port port, Line line, bool value)
{
//	if(port == Port::A && line == Line::Two) {
//		printf("Tape motor %s\n", value ? "on" : "off");
//	}
}

void UserPortVIA::set_serial_line_state(::Commodore::Serial::Line line, bool value)
{
	switch(line)
	{
		default: break;
		case ::Commodore::Serial::Line::Data: port_a_ = (port_a_ & ~0x02) | (value ? 0x02 : 0x00);	break;
		case ::Commodore::Serial::Line::Clock: port_a_ = (port_a_ & ~0x01) | (value ? 0x01 : 0x00);	break;
	}
}

void UserPortVIA::set_joystick_state(JoystickInput input, bool value)
{
	if(input != JoystickInput::Right)
	{
		port_a_ = (port_a_ & ~input) | (value ? 0 : input);
	}
}

void UserPortVIA::set_port_output(Port port, uint8_t value, uint8_t mask)
{
	// Line 7 of port A is inverted and output as serial ATN
	if(!port)
	{
		std::shared_ptr<::Commodore::Serial::Port> serialPort = serial_port_.lock();
		if(serialPort)
			serialPort->set_output(::Commodore::Serial::Line::Attention, (::Commodore::Serial::LineLevel)!(value&0x80));
	}
}

UserPortVIA::UserPortVIA() : port_a_(0xbf) {}

void UserPortVIA::set_serial_port(std::shared_ptr<::Commodore::Serial::Port> serialPort)
{
	serial_port_ = serialPort;
}

#pragma mark - KeyboardVIA

KeyboardVIA::KeyboardVIA() : port_b_(0xff)
{
	clear_all_keys();
}

void KeyboardVIA::set_key_state(uint16_t key, bool isPressed)
{
	if(isPressed)
		columns_[key & 7] &= ~(key >> 3);
	else
		columns_[key & 7] |= (key >> 3);
}

void KeyboardVIA::clear_all_keys()
{
	memset(columns_, 0xff, sizeof(columns_));
}

uint8_t KeyboardVIA::get_port_input(Port port)
{
	if(!port)
	{
		uint8_t result = 0xff;
		for(int c = 0; c < 8; c++)
		{
			if(!(activation_mask_&(1 << c)))
				result &= columns_[c];
		}
		return result;
	}

	return port_b_;
}

void KeyboardVIA::set_port_output(Port port, uint8_t value, uint8_t mask)
{
	if(port)
		activation_mask_ = (value & mask) | (~mask);
}

void KeyboardVIA::set_control_line_output(Port port, Line line, bool value)
{
	if(line == Line::Two)
	{
		std::shared_ptr<::Commodore::Serial::Port> serialPort = serial_port_.lock();
		if(serialPort)
		{
			// CB2 is inverted to become serial data; CA2 is inverted to become serial clock
			if(port == Port::A)
				serialPort->set_output(::Commodore::Serial::Line::Clock, (::Commodore::Serial::LineLevel)!value);
			else
				serialPort->set_output(::Commodore::Serial::Line::Data, (::Commodore::Serial::LineLevel)!value);
		}
	}
}

void KeyboardVIA::set_joystick_state(JoystickInput input, bool value)
{
	if(input == JoystickInput::Right)
	{
		port_b_ = (port_b_ & ~input) | (value ? 0 : input);
	}
}

void KeyboardVIA::set_serial_port(std::shared_ptr<::Commodore::Serial::Port> serialPort)
{
	serial_port_ = serialPort;
}

#pragma mark - SerialPort

void SerialPort::set_input(::Commodore::Serial::Line line, ::Commodore::Serial::LineLevel level)
{
	std::shared_ptr<UserPortVIA> userPortVIA = user_port_via_.lock();
	if(userPortVIA) userPortVIA->set_serial_line_state(line, (bool)level);
}

void SerialPort::set_user_port_via(std::shared_ptr<UserPortVIA> userPortVIA)
{
	user_port_via_ = userPortVIA;
}