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CLK/Machines/MasterSystem/MasterSystem.cpp
2024-02-16 21:50:15 -05:00

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//
// MasterSystem.cpp
// Clock Signal
//
// Created by Thomas Harte on 20/09/2018.
// Copyright © 2018 Thomas Harte. All rights reserved.
//
#include "MasterSystem.hpp"
#include "../../Processors/Z80/Z80.hpp"
#include "../../Components/9918/9918.hpp"
#include "../../Components/SN76489/SN76489.hpp"
#include "../../Components/OPx/OPLL.hpp"
#include "../MachineTypes.hpp"
#include "../../Configurable/Configurable.hpp"
#include "../../ClockReceiver/ForceInline.hpp"
#include "../../ClockReceiver/JustInTime.hpp"
#include "../../Outputs/Speaker/Implementation/LowpassSpeaker.hpp"
#include "../../Outputs/Speaker/Implementation/CompoundSource.hpp"
#include "../../Outputs/Log.hpp"
#include "../../Analyser/Static/Sega/Target.hpp"
#include <algorithm>
#include <cassert>
#include <iostream>
namespace {
constexpr int audio_divider = 1;
Log::Logger<Log::Source::MasterSystem> logger;
}
namespace Sega {
namespace MasterSystem {
class Joystick: public Inputs::ConcreteJoystick {
public:
Joystick() :
ConcreteJoystick({
Input(Input::Up),
Input(Input::Down),
Input(Input::Left),
Input(Input::Right),
Input(Input::Fire, 0),
Input(Input::Fire, 1)
}) {}
void did_set_input(const Input &digital_input, bool is_active) final {
switch(digital_input.type) {
default: return;
case Input::Up: if(is_active) state_ &= ~0x01; else state_ |= 0x01; break;
case Input::Down: if(is_active) state_ &= ~0x02; else state_ |= 0x02; break;
case Input::Left: if(is_active) state_ &= ~0x04; else state_ |= 0x04; break;
case Input::Right: if(is_active) state_ &= ~0x08; else state_ |= 0x08; break;
case Input::Fire:
switch(digital_input.info.control.index) {
default: break;
case 0: if(is_active) state_ &= ~0x10; else state_ |= 0x10; break;
case 1: if(is_active) state_ &= ~0x20; else state_ |= 0x20; break;
}
break;
}
}
uint8_t get_state() {
return state_;
}
private:
uint8_t state_ = 0xff;
};
template <Analyser::Static::Sega::Target::Model model> class ConcreteMachine:
public Machine,
public CPU::Z80::BusHandler,
public MachineTypes::TimedMachine,
public MachineTypes::ScanProducer,
public MachineTypes::AudioProducer,
public MachineTypes::KeyboardMachine,
public MachineTypes::JoystickMachine,
public Configurable::Device,
public Inputs::Keyboard::Delegate {
public:
ConcreteMachine(const Analyser::Static::Sega::Target &target, const ROMMachine::ROMFetcher &rom_fetcher) :
region_(target.region),
paging_scheme_(target.paging_scheme),
z80_(*this),
sn76489_(
(target.model == Target::Model::SG1000) ? TI::SN76489::Personality::SN76489 : TI::SN76489::Personality::SMS,
audio_queue_,
audio_divider),
opll_(audio_queue_, audio_divider),
mixer_(sn76489_, opll_),
speaker_(mixer_),
keyboard_({Inputs::Keyboard::Key::Enter, Inputs::Keyboard::Key::Escape}, {}) {
// Pick the clock rate based on the region.
const double clock_rate = target.region == Target::Region::Europe ? 3546893.0 : 3579540.0;
speaker_.set_input_rate(float(clock_rate / audio_divider));
set_clock_rate(clock_rate);
// Instantiate the joysticks.
joysticks_.emplace_back(new Joystick);
joysticks_.emplace_back(new Joystick);
// Clear the memory map.
map(read_pointers_, nullptr, 0x10000, 0);
map(write_pointers_, nullptr, 0x10000, 0);
// Take a copy of the cartridge and place it into memory.
if(!target.media.cartridges.empty()) {
cartridge_ = target.media.cartridges[0]->get_segments()[0].data;
}
if(cartridge_.size() < 48*1024) {
std::size_t new_space = 48*1024 - cartridge_.size();
cartridge_.resize(48*1024);
memset(&cartridge_[48*1024 - new_space], 0xff, new_space);
}
if(paging_scheme_ == Target::PagingScheme::Codemasters) {
// The Codemasters cartridges start with pages 0, 1 and 0 again initially visible.
paging_registers_[0] = 0;
paging_registers_[1] = 1;
paging_registers_[2] = 0;
}
// Load the BIOS if available.
//
// TODO: there's probably a million other versions of the Master System BIOS; try to build a
// CRC32 catalogue of those. So far:
//
// 0072ed54 = US/European BIOS 1.3
// 48d44a13 = Japanese BIOS 2.1
const bool is_japanese = target.region == Target::Region::Japan;
const ROM::Name bios_name = is_japanese ? ROM::Name::MasterSystemJapaneseBIOS : ROM::Name::MasterSystemWesternBIOS;
ROM::Request request(bios_name, true);
auto roms = rom_fetcher(request);
request.validate(roms);
const auto rom = roms.find(bios_name);
if(rom == roms.end()) {
// No BIOS found; attempt to boot as though it has already disabled itself.
has_bios_ = false;
memory_control_ |= 0x08;
std::cerr << "No BIOS found; attempting to start cartridge directly" << std::endl;
} else {
has_bios_ = true;
memcpy(&bios_, rom->second.data(), std::min(sizeof(bios_), rom->second.size()));
}
page_cartridge();
// Map RAM.
if constexpr (is_master_system(model)) {
map(read_pointers_, ram_, 8*1024, 0xc000, 0x10000);
map(write_pointers_, ram_, 8*1024, 0xc000, 0x10000);
} else {
map(read_pointers_, ram_, 1024, 0xc000, 0x10000);
map(write_pointers_, ram_, 1024, 0xc000, 0x10000);
}
// Apply a relatively low low-pass filter. More guidance needed here.
// TODO: this is disabled for now since it isn't applicable for the FM chip, I think.
// speaker_.set_high_frequency_cutoff(8000);
// Set default mixer levels: FM off, SN full-throttle.
set_mixer_levels(0);
keyboard_.set_delegate(this);
}
~ConcreteMachine() {
audio_queue_.flush();
}
void set_scan_target(Outputs::Display::ScanTarget *scan_target) final {
vdp_.last_valid()->set_tv_standard(
(region_ == Target::Region::Europe) ?
TI::TMS::TVStandard::PAL : TI::TMS::TVStandard::NTSC);
// Doing the following would be technically correct, but isn't
// especially thread-safe and won't make a substantial difference.
// time_until_debounce_ = vdp_->get_time_until_line(-1);
vdp_.last_valid()->set_scan_target(scan_target);
}
Outputs::Display::ScanStatus get_scaled_scan_status() const final {
return vdp_.last_valid()->get_scaled_scan_status();
}
void set_display_type(Outputs::Display::DisplayType display_type) final {
vdp_.last_valid()->set_display_type(display_type);
}
Outputs::Display::DisplayType get_display_type() const final {
return vdp_.last_valid()->get_display_type();
}
Outputs::Speaker::Speaker *get_speaker() final {
return &speaker_;
}
void run_for(const Cycles cycles) final {
z80_.run_for(cycles);
}
void flush_output(int outputs) final {
if(outputs & Output::Video) {
vdp_.flush();
}
if(outputs & Output::Audio) {
update_audio();
audio_queue_.perform();
}
}
forceinline HalfCycles perform_machine_cycle(const CPU::Z80::PartialMachineCycle &cycle) {
if(vdp_ += cycle.length) {
z80_.set_interrupt_line(vdp_->get_interrupt_line(), vdp_.last_sequence_point_overrun());
}
time_since_sn76489_update_ += cycle.length;
if(cycle.is_terminal()) {
uint16_t address = cycle.address ? *cycle.address : 0x0000;
switch(cycle.operation) {
case CPU::Z80::PartialMachineCycle::ReadOpcode:
case CPU::Z80::PartialMachineCycle::Read:
*cycle.value = read_pointers_[address >> 10] ? read_pointers_[address >> 10][address & 1023] : 0xff;
break;
case CPU::Z80::PartialMachineCycle::Write:
if(paging_scheme_ == Target::PagingScheme::Sega) {
if(address >= 0xfffd && cartridge_.size() > 48*1024) {
if(paging_registers_[address - 0xfffd] != *cycle.value) {
paging_registers_[address - 0xfffd] = *cycle.value;
page_cartridge();
}
}
} else {
// i.e. this is the Codemasters paging scheme.
if(!(address&0x3fff) && address < 0xc000) {
if(paging_registers_[address >> 14] != *cycle.value) {
paging_registers_[address >> 14] = *cycle.value;
page_cartridge();
}
}
}
if(write_pointers_[address >> 10]) write_pointers_[address >> 10][address & 1023] = *cycle.value;
// else logger.info().append("Ignored write to ROM");
break;
case CPU::Z80::PartialMachineCycle::Input:
switch(address & 0xc1) {
case 0x00:
logger.error().append("TODO: [input] memory control");
*cycle.value = 0xff;
break;
case 0x01:
logger.error().append("TODO: [input] I/O port control");
*cycle.value = 0xff;
break;
case 0x40:
*cycle.value = vdp_->get_current_line();
break;
case 0x41:
*cycle.value = vdp_.last_valid()->get_latched_horizontal_counter();
break;
case 0x80: case 0x81:
*cycle.value = vdp_->read(address);
z80_.set_interrupt_line(vdp_->get_interrupt_line());
break;
case 0xc0: {
if(memory_control_ & 0x4) {
if(has_fm_audio_ && (address & 0xff) == 0xf2) {
*cycle.value = opll_detection_word_;
} else {
*cycle.value = 0xff;
}
} else {
Joystick *const joypad1 = static_cast<Joystick *>(joysticks_[0].get());
Joystick *const joypad2 = static_cast<Joystick *>(joysticks_[1].get());
*cycle.value = uint8_t(joypad1->get_state() | (joypad2->get_state() << 6));
}
} break;
case 0xc1: {
if(memory_control_ & 0x4) {
*cycle.value = 0xff;
} else {
Joystick *const joypad2 = static_cast<Joystick *>(joysticks_[1].get());
*cycle.value =
(joypad2->get_state() >> 2) |
0x30 |
get_th_values();
}
} break;
default:
logger.error().append("[input] Clearly some sort of typo");
break;
}
break;
case CPU::Z80::PartialMachineCycle::Output:
switch(address & 0xc1) {
case 0x00: // i.e. even ports less than 0x40.
if constexpr (is_master_system(model)) {
// TODO: Obey the RAM enable.
logger.info().append("Memory control: %02x", memory_control_);
memory_control_ = *cycle.value;
page_cartridge();
}
break;
case 0x01: { // i.e. odd ports less than 0x40.
// A programmer can force the TH lines to 0 here,
// causing a phoney lightgun latch, so check for any
// discontinuity in TH inputs.
const auto previous_ths = get_th_values();
io_port_control_ = *cycle.value;
const auto new_ths = get_th_values();
// Latch if either TH has newly gone to 1.
if((new_ths^previous_ths)&new_ths) {
vdp_->latch_horizontal_counter();
}
} break;
case 0x40: case 0x41: // i.e. ports 0x400x7f.
update_audio();
sn76489_.write(*cycle.value);
break;
case 0x80: case 0x81: // i.e. ports 0x800xbf.
vdp_->write(address, *cycle.value);
z80_.set_interrupt_line(vdp_->get_interrupt_line());
break;
case 0xc1: case 0xc0: // i.e. ports 0xc00xff.
if(has_fm_audio_) {
switch(address & 0xff) {
case 0xf0: case 0xf1:
update_audio();
opll_.write(address, *cycle.value);
break;
case 0xf2:
opll_detection_word_ = *cycle.value;
set_mixer_levels(opll_detection_word_);
break;
}
}
break;
default:
logger.error().append("[output] Clearly some sort of typo");
break;
}
break;
/*
TODO: implementation of the below is incomplete.
Re: io_port_control_
Set the TH pins for ports A and B as outputs. Set their output level
to any value desired by writing to bits 7 and 5. Read the state of both
TH pins back through bits 7 and 6 of port $DD. If the data returned is
the same as the data written, it's an export machine, otherwise it's
a domestic one.
— Charles MacDonald
*/
case CPU::Z80::PartialMachineCycle::Interrupt:
*cycle.value = 0xff;
break;
default: break;
}
}
// The pause button is debounced and takes effect only one line before pixels
// begin; time_until_debounce_ keeps track of the time until then.
time_until_debounce_ -= cycle.length;
if(time_until_debounce_ <= HalfCycles(0)) {
z80_.set_non_maskable_interrupt_line(pause_is_pressed_);
time_until_debounce_ = vdp_->get_time_until_line(-1);
}
return HalfCycles(0);
}
const std::vector<std::unique_ptr<Inputs::Joystick>> &get_joysticks() final {
return joysticks_;
}
// MARK: - Keyboard (i.e. the pause and reset buttons).
Inputs::Keyboard &get_keyboard() final {
return keyboard_;
}
bool keyboard_did_change_key(Inputs::Keyboard *, Inputs::Keyboard::Key key, bool is_pressed) final {
if(key == Inputs::Keyboard::Key::Enter) {
pause_is_pressed_ = is_pressed;
return true;
}
if(key == Inputs::Keyboard::Key::Escape) {
reset_is_pressed_ = is_pressed;
return true;
}
return false;
}
void reset_all_keys(Inputs::Keyboard *) final {
}
// MARK: - Configuration options.
std::unique_ptr<Reflection::Struct> get_options() final {
auto options = std::make_unique<Options>(Configurable::OptionsType::UserFriendly);
options->output = get_video_signal_configurable();
return options;
}
void set_options(const std::unique_ptr<Reflection::Struct> &str) final {
const auto options = dynamic_cast<Options *>(str.get());
set_video_signal_configurable(options->output);
}
private:
static constexpr TI::TMS::Personality tms_personality() {
switch(model) {
default:
case Target::Model::SG1000: return TI::TMS::TMS9918A;
case Target::Model::MasterSystem: return TI::TMS::SMSVDP;
case Target::Model::MasterSystem2: return TI::TMS::SMS2VDP;
}
}
inline uint8_t get_th_values() {
// Quick not on TH inputs here: if either is setup as an output, then the
// currently output level is returned. Otherwise they're fixed at 1.
return
uint8_t(
((io_port_control_ & 0x02) << 5) | ((io_port_control_&0x20) << 1) |
((io_port_control_ & 0x08) << 4) | (io_port_control_&0x80)
);
}
inline void update_audio() {
speaker_.run_for(audio_queue_, time_since_sn76489_update_.divide_cycles(Cycles(audio_divider)));
}
void set_mixer_levels(uint8_t mode) {
// This is as per the audio control register;
// see https://www.smspower.org/Development/AudioControlPort
update_audio();
audio_queue_.enqueue([this, mode] {
switch(mode & 3) {
case 0: // SN76489 only; the default.
mixer_.set_relative_volumes({1.0f, 0.0f});
break;
case 1: // FM only.
mixer_.set_relative_volumes({0.0f, 1.0f});
break;
case 2: // No audio.
mixer_.set_relative_volumes({0.0f, 0.0f});
break;
case 3: // Both FM and SN76489.
mixer_.set_relative_volumes({0.5f, 0.5f});
break;
}
});
}
using Target = Analyser::Static::Sega::Target;
const Target::Region region_;
const Target::PagingScheme paging_scheme_;
CPU::Z80::Processor<ConcreteMachine, false, false> z80_;
JustInTimeActor<TI::TMS::TMS9918<tms_personality()>> vdp_;
Concurrency::AsyncTaskQueue<false> audio_queue_;
TI::SN76489 sn76489_;
Yamaha::OPL::OPLL opll_;
Outputs::Speaker::CompoundSource<decltype(sn76489_), decltype(opll_)> mixer_;
Outputs::Speaker::PullLowpass<decltype(mixer_)> speaker_;
uint8_t opll_detection_word_ = 0xff;
std::vector<std::unique_ptr<Inputs::Joystick>> joysticks_;
Inputs::Keyboard keyboard_;
bool reset_is_pressed_ = false, pause_is_pressed_ = false;
HalfCycles time_since_sn76489_update_;
HalfCycles time_until_debounce_;
uint8_t ram_[8*1024];
uint8_t bios_[8*1024];
std::vector<uint8_t> cartridge_;
uint8_t io_port_control_ = 0x0f;
// This is a static constexpr for now; I may use it in the future.
static constexpr bool has_fm_audio_ = true;
// The memory map has a 1kb granularity; this is determined by the SG1000's 1kb of RAM.
const uint8_t *read_pointers_[64];
uint8_t *write_pointers_[64];
template <typename T> void map(T **target, uint8_t *source, size_t size, size_t start_address, size_t end_address = 0) {
if(!end_address) end_address = start_address + size;
for(auto address = start_address; address < end_address; address += 1024) {
target[address >> 10] = source ? &source[(address - start_address) & (size - 1)] : nullptr;
}
}
uint8_t paging_registers_[3] = {0, 1, 2};
uint8_t memory_control_ = 0;
void page_cartridge() {
// Either install the cartridge or don't; Japanese machines can't see
// anything but the cartridge.
if(!(memory_control_ & 0x40) || region_ == Target::Region::Japan) {
for(size_t c = 0; c < 3; ++c) {
const size_t start_addr = (paging_registers_[c] * 0x4000) % cartridge_.size();
map(
read_pointers_,
cartridge_.data() + start_addr,
std::min(size_t(0x4000), cartridge_.size() - start_addr),
c * 0x4000);
}
// The first 1kb doesn't page though, if this is the Sega paging scheme.
if(paging_scheme_ == Target::PagingScheme::Sega) {
map(read_pointers_, cartridge_.data(), 0x400, 0x0000);
}
} else {
map(read_pointers_, nullptr, 0xc000, 0x0000);
}
// Throw the BIOS on top if this machine has one and it isn't disabled.
if(has_bios_ && !(memory_control_ & 0x08)) {
map(read_pointers_, bios_, 8*1024, 0);
}
}
bool has_bios_ = true;
};
}
}
using namespace Sega::MasterSystem;
std::unique_ptr<Machine> Machine::MasterSystem(const Analyser::Static::Target *target, const ROMMachine::ROMFetcher &rom_fetcher) {
using Target = Analyser::Static::Sega::Target;
const Target *const sega_target = dynamic_cast<const Target *>(target);
switch(sega_target->model) {
case Target::Model::SG1000: return std::make_unique<ConcreteMachine<Target::Model::SG1000>>(*sega_target, rom_fetcher);
case Target::Model::MasterSystem: return std::make_unique<ConcreteMachine<Target::Model::MasterSystem>>(*sega_target, rom_fetcher);
case Target::Model::MasterSystem2: return std::make_unique<ConcreteMachine<Target::Model::MasterSystem2>>(*sega_target, rom_fetcher);
default:
assert(false);
return nullptr;
}
}