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562 lines
17 KiB
C++
562 lines
17 KiB
C++
//
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// MasterSystem.cpp
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// Clock Signal
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//
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// Created by Thomas Harte on 20/09/2018.
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// Copyright © 2018 Thomas Harte. All rights reserved.
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//
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#include "MasterSystem.hpp"
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#include "../../Processors/Z80/Z80.hpp"
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#include "../../Components/9918/9918.hpp"
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#include "../../Components/SN76489/SN76489.hpp"
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#include "../../Components/OPx/OPLL.hpp"
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#include "../MachineTypes.hpp"
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#include "../../Configurable/Configurable.hpp"
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#include "../../ClockReceiver/ForceInline.hpp"
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#include "../../ClockReceiver/JustInTime.hpp"
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#include "../../Outputs/Speaker/Implementation/LowpassSpeaker.hpp"
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#include "../../Outputs/Speaker/Implementation/CompoundSource.hpp"
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#define LOG_PREFIX "[SMS] "
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#include "../../Outputs/Log.hpp"
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#include "../../Analyser/Static/Sega/Target.hpp"
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#include <algorithm>
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#include <iostream>
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namespace {
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constexpr int audio_divider = 1;
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}
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namespace Sega {
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namespace MasterSystem {
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class Joystick: public Inputs::ConcreteJoystick {
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public:
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Joystick() :
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ConcreteJoystick({
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Input(Input::Up),
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Input(Input::Down),
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Input(Input::Left),
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Input(Input::Right),
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Input(Input::Fire, 0),
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Input(Input::Fire, 1)
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}) {}
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void did_set_input(const Input &digital_input, bool is_active) final {
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switch(digital_input.type) {
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default: return;
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case Input::Up: if(is_active) state_ &= ~0x01; else state_ |= 0x01; break;
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case Input::Down: if(is_active) state_ &= ~0x02; else state_ |= 0x02; break;
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case Input::Left: if(is_active) state_ &= ~0x04; else state_ |= 0x04; break;
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case Input::Right: if(is_active) state_ &= ~0x08; else state_ |= 0x08; break;
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case Input::Fire:
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switch(digital_input.info.control.index) {
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default: break;
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case 0: if(is_active) state_ &= ~0x10; else state_ |= 0x10; break;
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case 1: if(is_active) state_ &= ~0x20; else state_ |= 0x20; break;
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}
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break;
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}
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}
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uint8_t get_state() {
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return state_;
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}
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private:
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uint8_t state_ = 0xff;
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};
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class ConcreteMachine:
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public Machine,
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public CPU::Z80::BusHandler,
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public MachineTypes::TimedMachine,
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public MachineTypes::ScanProducer,
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public MachineTypes::AudioProducer,
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public MachineTypes::KeyboardMachine,
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public MachineTypes::JoystickMachine,
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public Configurable::Device,
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public Inputs::Keyboard::Delegate {
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public:
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ConcreteMachine(const Analyser::Static::Sega::Target &target, const ROMMachine::ROMFetcher &rom_fetcher) :
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model_(target.model),
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region_(target.region),
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paging_scheme_(target.paging_scheme),
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z80_(*this),
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vdp_(tms_personality_for_model(target.model)),
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sn76489_(
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(target.model == Target::Model::SG1000) ? TI::SN76489::Personality::SN76489 : TI::SN76489::Personality::SMS,
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audio_queue_,
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audio_divider),
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opll_(audio_queue_, audio_divider),
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mixer_(sn76489_, opll_),
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speaker_(mixer_),
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keyboard_({Inputs::Keyboard::Key::Enter, Inputs::Keyboard::Key::Escape}, {}) {
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// Pick the clock rate based on the region.
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const double clock_rate = target.region == Target::Region::Europe ? 3546893.0 : 3579540.0;
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speaker_.set_input_rate(float(clock_rate / audio_divider));
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set_clock_rate(clock_rate);
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// Instantiate the joysticks.
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joysticks_.emplace_back(new Joystick);
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joysticks_.emplace_back(new Joystick);
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// Clear the memory map.
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map(read_pointers_, nullptr, 0x10000, 0);
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map(write_pointers_, nullptr, 0x10000, 0);
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// Take a copy of the cartridge and place it into memory.
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if(!target.media.cartridges.empty()) {
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cartridge_ = target.media.cartridges[0]->get_segments()[0].data;
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}
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if(cartridge_.size() < 48*1024) {
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std::size_t new_space = 48*1024 - cartridge_.size();
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cartridge_.resize(48*1024);
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memset(&cartridge_[48*1024 - new_space], 0xff, new_space);
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}
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if(paging_scheme_ == Target::PagingScheme::Codemasters) {
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// The Codemasters cartridges start with pages 0, 1 and 0 again initially visible.
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paging_registers_[0] = 0;
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paging_registers_[1] = 1;
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paging_registers_[2] = 0;
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}
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// Load the BIOS if available.
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//
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// TODO: there's probably a million other versions of the Master System BIOS; try to build a
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// CRC32 catalogue of those. So far:
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//
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// 0072ed54 = US/European BIOS 1.3
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// 48d44a13 = Japanese BIOS 2.1
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const bool is_japanese = target.region == Target::Region::Japan;
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const ROM::Name bios_name = is_japanese ? ROM::Name::MasterSystemJapaneseBIOS : ROM::Name::MasterSystemWesternBIOS;
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ROM::Request request(bios_name, true);
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auto roms = rom_fetcher(request);
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request.validate(roms);
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const auto rom = roms.find(bios_name);
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if(rom == roms.end()) {
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// No BIOS found; attempt to boot as though it has already disabled itself.
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has_bios_ = false;
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memory_control_ |= 0x08;
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std::cerr << "No BIOS found; attempting to start cartridge directly" << std::endl;
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} else {
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has_bios_ = true;
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memcpy(&bios_, rom->second.data(), std::min(sizeof(bios_), rom->second.size()));
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}
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page_cartridge();
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// Map RAM.
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if(is_master_system(model_)) {
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map(read_pointers_, ram_, 8*1024, 0xc000, 0x10000);
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map(write_pointers_, ram_, 8*1024, 0xc000, 0x10000);
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} else {
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map(read_pointers_, ram_, 1024, 0xc000, 0x10000);
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map(write_pointers_, ram_, 1024, 0xc000, 0x10000);
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}
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// Apply a relatively low low-pass filter. More guidance needed here.
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// TODO: this is disabled for now since it isn't applicable for the FM chip, I think.
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// speaker_.set_high_frequency_cutoff(8000);
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// Set default mixer levels: FM off, SN full-throttle.
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set_mixer_levels(0);
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keyboard_.set_delegate(this);
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}
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~ConcreteMachine() {
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audio_queue_.flush();
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}
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void set_scan_target(Outputs::Display::ScanTarget *scan_target) final {
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vdp_->set_tv_standard(
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(region_ == Target::Region::Europe) ?
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TI::TMS::TVStandard::PAL : TI::TMS::TVStandard::NTSC);
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time_until_debounce_ = vdp_->get_time_until_line(-1);
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vdp_->set_scan_target(scan_target);
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}
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Outputs::Display::ScanStatus get_scaled_scan_status() const final {
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return vdp_->get_scaled_scan_status();
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}
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void set_display_type(Outputs::Display::DisplayType display_type) final {
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vdp_->set_display_type(display_type);
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}
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Outputs::Display::DisplayType get_display_type() const final {
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return vdp_->get_display_type();
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}
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Outputs::Speaker::Speaker *get_speaker() final {
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return &speaker_;
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}
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void run_for(const Cycles cycles) final {
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z80_.run_for(cycles);
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}
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forceinline HalfCycles perform_machine_cycle(const CPU::Z80::PartialMachineCycle &cycle) {
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if(vdp_ += cycle.length) {
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z80_.set_interrupt_line(vdp_->get_interrupt_line(), vdp_.last_sequence_point_overrun());
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}
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time_since_sn76489_update_ += cycle.length;
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if(cycle.is_terminal()) {
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uint16_t address = cycle.address ? *cycle.address : 0x0000;
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switch(cycle.operation) {
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case CPU::Z80::PartialMachineCycle::ReadOpcode:
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case CPU::Z80::PartialMachineCycle::Read:
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*cycle.value = read_pointers_[address >> 10] ? read_pointers_[address >> 10][address & 1023] : 0xff;
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break;
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case CPU::Z80::PartialMachineCycle::Write:
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if(paging_scheme_ == Target::PagingScheme::Sega) {
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if(address >= 0xfffd && cartridge_.size() > 48*1024) {
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if(paging_registers_[address - 0xfffd] != *cycle.value) {
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paging_registers_[address - 0xfffd] = *cycle.value;
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page_cartridge();
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}
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}
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} else {
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// i.e. this is the Codemasters paging scheme.
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if(!(address&0x3fff) && address < 0xc000) {
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if(paging_registers_[address >> 14] != *cycle.value) {
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paging_registers_[address >> 14] = *cycle.value;
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page_cartridge();
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}
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}
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}
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if(write_pointers_[address >> 10]) write_pointers_[address >> 10][address & 1023] = *cycle.value;
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// else LOG("Ignored write to ROM");
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break;
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case CPU::Z80::PartialMachineCycle::Input:
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switch(address & 0xc1) {
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case 0x00:
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LOG("TODO: [input] memory control");
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*cycle.value = 0xff;
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break;
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case 0x01:
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LOG("TODO: [input] I/O port control");
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*cycle.value = 0xff;
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break;
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case 0x40:
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*cycle.value = vdp_->get_current_line();
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break;
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case 0x41:
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*cycle.value = vdp_.last_valid()->get_latched_horizontal_counter();
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break;
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case 0x80: case 0x81:
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*cycle.value = vdp_->read(address);
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z80_.set_interrupt_line(vdp_->get_interrupt_line());
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break;
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case 0xc0: {
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if(memory_control_ & 0x4) {
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if(has_fm_audio_ && (address & 0xff) == 0xf2) {
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*cycle.value = opll_detection_word_;
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} else {
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*cycle.value = 0xff;
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}
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} else {
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Joystick *const joypad1 = static_cast<Joystick *>(joysticks_[0].get());
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Joystick *const joypad2 = static_cast<Joystick *>(joysticks_[1].get());
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*cycle.value = uint8_t(joypad1->get_state() | (joypad2->get_state() << 6));
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}
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} break;
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case 0xc1: {
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if(memory_control_ & 0x4) {
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*cycle.value = 0xff;
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} else {
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Joystick *const joypad2 = static_cast<Joystick *>(joysticks_[1].get());
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*cycle.value =
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(joypad2->get_state() >> 2) |
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0x30 |
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get_th_values();
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}
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} break;
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default:
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ERROR("[input] Clearly some sort of typo");
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break;
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}
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break;
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case CPU::Z80::PartialMachineCycle::Output:
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switch(address & 0xc1) {
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case 0x00: // i.e. even ports less than 0x40.
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if(is_master_system(model_)) {
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// TODO: Obey the RAM enable.
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LOG("Memory control: " << PADHEX(2) << memory_control_);
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memory_control_ = *cycle.value;
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page_cartridge();
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}
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break;
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case 0x01: { // i.e. odd ports less than 0x40.
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// A programmer can force the TH lines to 0 here,
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// causing a phoney lightgun latch, so check for any
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// discontinuity in TH inputs.
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const auto previous_ths = get_th_values();
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io_port_control_ = *cycle.value;
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const auto new_ths = get_th_values();
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// Latch if either TH has newly gone to 1.
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if((new_ths^previous_ths)&new_ths) {
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vdp_->latch_horizontal_counter();
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}
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} break;
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case 0x40: case 0x41: // i.e. ports 0x40–0x7f.
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update_audio();
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sn76489_.write(*cycle.value);
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break;
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case 0x80: case 0x81: // i.e. ports 0x80–0xbf.
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vdp_->write(address, *cycle.value);
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z80_.set_interrupt_line(vdp_->get_interrupt_line());
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break;
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case 0xc1: case 0xc0: // i.e. ports 0xc0–0xff.
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if(has_fm_audio_) {
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switch(address & 0xff) {
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case 0xf0: case 0xf1:
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update_audio();
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opll_.write(address, *cycle.value);
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break;
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case 0xf2:
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opll_detection_word_ = *cycle.value;
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set_mixer_levels(opll_detection_word_);
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break;
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}
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}
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break;
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default:
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ERROR("[output] Clearly some sort of typo");
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break;
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}
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break;
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/*
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TODO: implementation of the below is incomplete.
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Re: io_port_control_
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Set the TH pins for ports A and B as outputs. Set their output level
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to any value desired by writing to bits 7 and 5. Read the state of both
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TH pins back through bits 7 and 6 of port $DD. If the data returned is
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the same as the data written, it's an export machine, otherwise it's
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a domestic one.
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— Charles MacDonald
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*/
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case CPU::Z80::PartialMachineCycle::Interrupt:
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*cycle.value = 0xff;
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break;
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default: break;
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}
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}
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// The pause button is debounced and takes effect only one line before pixels
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// begin; time_until_debounce_ keeps track of the time until then.
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time_until_debounce_ -= cycle.length;
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if(time_until_debounce_ <= HalfCycles(0)) {
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z80_.set_non_maskable_interrupt_line(pause_is_pressed_);
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time_until_debounce_ = vdp_->get_time_until_line(-1);
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}
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return HalfCycles(0);
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}
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void flush() {
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vdp_.flush();
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update_audio();
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audio_queue_.perform();
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}
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const std::vector<std::unique_ptr<Inputs::Joystick>> &get_joysticks() final {
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return joysticks_;
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}
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// MARK: - Keyboard (i.e. the pause and reset buttons).
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Inputs::Keyboard &get_keyboard() final {
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return keyboard_;
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}
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bool keyboard_did_change_key(Inputs::Keyboard *, Inputs::Keyboard::Key key, bool is_pressed) final {
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if(key == Inputs::Keyboard::Key::Enter) {
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pause_is_pressed_ = is_pressed;
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return true;
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}
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if(key == Inputs::Keyboard::Key::Escape) {
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reset_is_pressed_ = is_pressed;
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return true;
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}
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return false;
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}
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void reset_all_keys(Inputs::Keyboard *) final {
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}
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// MARK: - Configuration options.
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std::unique_ptr<Reflection::Struct> get_options() final {
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auto options = std::make_unique<Options>(Configurable::OptionsType::UserFriendly);
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options->output = get_video_signal_configurable();
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return options;
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}
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void set_options(const std::unique_ptr<Reflection::Struct> &str) final {
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const auto options = dynamic_cast<Options *>(str.get());
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set_video_signal_configurable(options->output);
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}
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private:
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static TI::TMS::Personality tms_personality_for_model(Analyser::Static::Sega::Target::Model model) {
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switch(model) {
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default:
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case Target::Model::SG1000: return TI::TMS::TMS9918A;
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case Target::Model::MasterSystem: return TI::TMS::SMSVDP;
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case Target::Model::MasterSystem2: return TI::TMS::SMS2VDP;
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}
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}
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inline uint8_t get_th_values() {
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// Quick not on TH inputs here: if either is setup as an output, then the
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// currently output level is returned. Otherwise they're fixed at 1.
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return
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uint8_t(
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((io_port_control_ & 0x02) << 5) | ((io_port_control_&0x20) << 1) |
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((io_port_control_ & 0x08) << 4) | (io_port_control_&0x80)
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);
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}
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inline void update_audio() {
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speaker_.run_for(audio_queue_, time_since_sn76489_update_.divide_cycles(Cycles(audio_divider)));
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}
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void set_mixer_levels(uint8_t mode) {
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// This is as per the audio control register;
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// see https://www.smspower.org/Development/AudioControlPort
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update_audio();
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audio_queue_.defer([this, mode] {
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switch(mode & 3) {
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case 0: // SN76489 only; the default.
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mixer_.set_relative_volumes({1.0f, 0.0f});
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break;
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case 1: // FM only.
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mixer_.set_relative_volumes({0.0f, 1.0f});
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break;
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case 2: // No audio.
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mixer_.set_relative_volumes({0.0f, 0.0f});
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break;
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case 3: // Both FM and SN76489.
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mixer_.set_relative_volumes({0.5f, 0.5f});
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break;
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}
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});
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}
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using Target = Analyser::Static::Sega::Target;
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const Target::Model model_;
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const Target::Region region_;
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const Target::PagingScheme paging_scheme_;
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CPU::Z80::Processor<ConcreteMachine, false, false> z80_;
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JustInTimeActor<TI::TMS::TMS9918> vdp_;
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Concurrency::DeferringAsyncTaskQueue audio_queue_;
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TI::SN76489 sn76489_;
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Yamaha::OPL::OPLL opll_;
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Outputs::Speaker::CompoundSource<decltype(sn76489_), decltype(opll_)> mixer_;
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Outputs::Speaker::LowpassSpeaker<decltype(mixer_)> speaker_;
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uint8_t opll_detection_word_ = 0xff;
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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;
|
||
|
||
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);
|
||
return new ConcreteMachine(*sega_target, rom_fetcher);
|
||
}
|
||
|
||
Machine::~Machine() {}
|