1
0
mirror of https://github.com/TomHarte/CLK.git synced 2024-11-30 04:50:08 +00:00
CLK/Machines/Commodore/Vic-20/Vic20.cpp

445 lines
14 KiB
C++

//
// 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 "../../../Storage/Tape/Parsers/Commodore.hpp"
#include "../../../StaticAnalyser/StaticAnalyser.hpp"
#include "CharacterMapper.hpp"
using namespace Commodore::Vic20;
Machine::Machine() :
rom_(nullptr),
is_running_at_zero_cost_(false),
tape_(new Storage::Tape::BinaryTapePlayer(1022727)),
user_port_via_(new UserPortVIA),
keyboard_via_(new KeyboardVIA),
serial_port_(new SerialPort),
serial_bus_(new ::Commodore::Serial::Bus) {
// communicate the tape to the user-port VIA
user_port_via_->set_tape(tape_);
// 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_;
}
Cycles Machine::perform_bus_operation(CPU::MOS6502::BusOperation operation, uint16_t address, uint8_t *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() && operation == CPU::MOS6502::BusOperation::ReadOpcode) {
if(address == 0xf7b2) {
// Address 0xf7b2 contains a JSR to 0xf8c0 that will fill the tape buffer with the next header.
// So cancel that via a double NOP and fill in the next header programmatically.
Storage::Tape::Commodore::Parser parser;
std::unique_ptr<Storage::Tape::Commodore::Header> header = parser.get_next_header(tape_->get_tape());
// serialise to wherever b2:b3 points
uint16_t tape_buffer_pointer = (uint16_t)user_basic_memory_[0xb2] | (uint16_t)(user_basic_memory_[0xb3] << 8);
if(header) {
header->serialise(&user_basic_memory_[tape_buffer_pointer], 0x8000 - tape_buffer_pointer);
} else {
// no header found, so store end-of-tape
user_basic_memory_[tape_buffer_pointer] = 0x05; // i.e. end of tape
}
// clear status and the verify flag
user_basic_memory_[0x90] = 0;
user_basic_memory_[0x93] = 0;
*value = 0x0c; // i.e. NOP abs
} else if(address == 0xf90b) {
uint8_t x = (uint8_t)get_value_of_register(CPU::MOS6502::Register::X);
if(x == 0xe) {
Storage::Tape::Commodore::Parser parser;
std::unique_ptr<Storage::Tape::Commodore::Data> data = parser.get_next_data(tape_->get_tape());
uint16_t start_address, end_address;
start_address = (uint16_t)(user_basic_memory_[0xc1] | (user_basic_memory_[0xc2] << 8));
end_address = (uint16_t)(user_basic_memory_[0xae] | (user_basic_memory_[0xaf] << 8));
// perform a via-processor_write_memory_map_ memcpy
uint8_t *data_ptr = data->data.data();
size_t data_left = data->data.size();
while(data_left && start_address != end_address) {
uint8_t *page = processor_write_memory_map_[start_address >> 10];
if(page) page[start_address & 0x3ff] = *data_ptr;
data_ptr++;
start_address++;
data_left--;
}
// set tape status, carry and flag
user_basic_memory_[0x90] |= 0x40;
uint8_t flags = (uint8_t)get_value_of_register(CPU::MOS6502::Register::Flags);
flags &= ~(uint8_t)(CPU::MOS6502::Flag::Carry | CPU::MOS6502::Flag::Interrupt);
set_value_of_register(CPU::MOS6502::Register::Flags, flags);
// to ensure that execution proceeds to 0xfccf, pretend a NOP was here and
// ensure that the PC leaps to 0xfccf
set_value_of_register(CPU::MOS6502::Register::ProgramCounter, 0xfccf);
*value = 0xea; // i.e. NOP implied
}
}
}
} 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 == CPU::MOS6502::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));
return Cycles(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_.resize(length);
memcpy(drive_rom_.data(), data, length);
install_disk_rom();
return;
}
if(target) {
size_t length_to_copy = std::min(max_length, length);
memcpy(target, data, length_to_copy);
}
}
#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(target.loadingCommand.length()) {
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::set_typer_for_string(const char *string) {
std::unique_ptr<CharacterMapper> mapper(new CharacterMapper());
Utility::TypeRecipient::set_typer_for_string(string, std::move(mapper));
}
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_.empty() && c1540_) {
c1540_->set_rom(drive_rom_);
c1540_->run_for(Cycles(2000000));
drive_rom_.clear();
}
}
#pragma mark - UserPortVIA
uint8_t UserPortVIA::get_port_input(Port port) {
if(!port) {
return port_a_ | (tape_->has_tape() ? 0x00 : 0x40);
}
return 0xff;
}
void UserPortVIA::set_control_line_output(Port port, Line line, bool value) {
if(port == Port::A && line == Line::Two) {
tape_->set_motor_control(!value);
}
}
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;
}
void UserPortVIA::set_tape(std::shared_ptr<Storage::Tape::BinaryTapePlayer> tape) {
tape_ = tape;
}
#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;
}