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CLK/Machines/MasterSystem/MasterSystem.cpp
2018-10-06 14:26:00 -04:00

349 lines
10 KiB
C++

//
// 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 "../CRTMachine.hpp"
#include "../JoystickMachine.hpp"
#include "../../ClockReceiver/ForceInline.hpp"
#include "../../Outputs/Speaker/Implementation/LowpassSpeaker.hpp"
#include "../../Analyser/Static/Sega/Target.hpp"
#include <algorithm>
namespace {
const int sn76489_divider = 2;
}
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) override {
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;
};
class ConcreteMachine:
public Machine,
public CPU::Z80::BusHandler,
public CRTMachine::Machine,
public JoystickMachine::Machine {
public:
ConcreteMachine(const Analyser::Static::Sega::Target &target, const ROMMachine::ROMFetcher &rom_fetcher) :
model_(target.model),
z80_(*this),
sn76489_(
(target.model == Analyser::Static::Sega::Target::Model::SG1000) ? TI::SN76489::Personality::SN76489 : TI::SN76489::Personality::SMS,
audio_queue_,
sn76489_divider),
speaker_(sn76489_) {
speaker_.set_input_rate(3579545.0f / static_cast<float>(sn76489_divider));
set_clock_rate(3579545);
// 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.
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);
}
page_cartridge();
// Establish the BIOS (if relevant) and RAM.
if(target.model == Analyser::Static::Sega::Target::Model::MasterSystem) {
const auto roms = rom_fetcher("MasterSystem", {"bios.sms"});
if(!roms[0]) {
throw ROMMachine::Error::MissingROMs;
}
roms[0]->resize(8*1024);
memcpy(&bios_, roms[0]->data(), roms[0]->size());
map(read_pointers_, bios_, 8*1024, 0);
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);
}
}
~ConcreteMachine() {
audio_queue_.flush();
}
void setup_output(float aspect_ratio) override {
vdp_.reset(new TI::TMS::TMS9918(model_ == Analyser::Static::Sega::Target::Model::SG1000 ? TI::TMS::TMS9918A : TI::TMS::SMSVDP));
// get_crt()->set_video_signal(Outputs::CRT::VideoSignal::Composite);
}
void close_output() override {
vdp_.reset();
}
Outputs::CRT::CRT *get_crt() override {
return vdp_->get_crt();
}
Outputs::Speaker::Speaker *get_speaker() override {
return &speaker_;
}
void run_for(const Cycles cycles) override {
z80_.run_for(cycles);
}
forceinline HalfCycles perform_machine_cycle(const CPU::Z80::PartialMachineCycle &cycle) {
time_since_vdp_update_ += cycle.length;
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(address >= 0xfffd && cartridge_.size() > 48*1024) {
if(paging_registers_[address - 0xfffd] != *cycle.value) {
paging_registers_[address - 0xfffd] = *cycle.value;
page_cartridge();
}
}
if(write_pointers_[address >> 10]) write_pointers_[address >> 10][address & 1023] = *cycle.value;
break;
case CPU::Z80::PartialMachineCycle::Input:
switch(address & 0xc1) {
case 0x00:
printf("TODO: [input] memory control\n");
*cycle.value = 0xff;
break;
case 0x01:
printf("TODO: [input] I/O port control\n");
*cycle.value = 0xff;
break;
case 0x40: case 0x41:
update_video();
*cycle.value = vdp_->get_current_line();
break;
case 0x80: case 0x81:
update_video();
*cycle.value = vdp_->get_register(address);
z80_.set_interrupt_line(vdp_->get_interrupt_line());
time_until_interrupt_ = vdp_->get_time_until_interrupt();
break;
case 0xc0: {
Joystick *const joypad1 = static_cast<Joystick *>(joysticks_[0].get());
Joystick *const joypad2 = static_cast<Joystick *>(joysticks_[1].get());
*cycle.value = static_cast<uint8_t>(joypad1->get_state() | (joypad2->get_state() << 6));
} break;
case 0xc1: {
Joystick *const joypad2 = static_cast<Joystick *>(joysticks_[1].get());
*cycle.value = (joypad2->get_state() >> 2) | 0xf;
} break;
default:
printf("[input] Clearly some sort of typo\n");
break;
}
break;
case CPU::Z80::PartialMachineCycle::Output:
switch(address & 0xc1) {
case 0x00:
if(model_ == Analyser::Static::Sega::Target::Model::MasterSystem) {
// TODO: Obey the RAM enable.
memory_control_ = *cycle.value;
page_cartridge();
}
break;
case 0x01:
printf("TODO: [output] I/O port control\n");
break;
case 0x40: case 0x41:
update_audio();
sn76489_.set_register(*cycle.value);
break;
case 0x80: case 0x81:
update_video();
vdp_->set_register(address, *cycle.value);
z80_.set_interrupt_line(vdp_->get_interrupt_line());
time_until_interrupt_ = vdp_->get_time_until_interrupt();
break;
case 0xc0:
// printf("TODO: [output] I/O port A/N [%02x]\n", *cycle.value);
break;
case 0xc1:
printf("TODO: [output] I/O port B/misc\n");
break;
default:
printf("[output] Clearly some sort of typo\n");
break;
}
break;
case CPU::Z80::PartialMachineCycle::Interrupt:
*cycle.value = 0xff;
break;
default: break;
}
}
if(time_until_interrupt_ > 0) {
time_until_interrupt_ -= cycle.length;
if(time_until_interrupt_ <= HalfCycles(0)) {
z80_.set_interrupt_line(true, time_until_interrupt_);
}
}
return HalfCycles(0);
}
void flush() {
update_video();
update_audio();
audio_queue_.perform();
}
std::vector<std::unique_ptr<Inputs::Joystick>> &get_joysticks() override {
return joysticks_;
}
private:
inline void update_audio() {
speaker_.run_for(audio_queue_, time_since_sn76489_update_.divide_cycles(Cycles(sn76489_divider)));
}
inline void update_video() {
vdp_->run_for(time_since_vdp_update_.flush());
}
Analyser::Static::Sega::Target::Model model_;
CPU::Z80::Processor<ConcreteMachine, false, false> z80_;
std::unique_ptr<TI::TMS::TMS9918> vdp_;
Concurrency::DeferringAsyncTaskQueue audio_queue_;
TI::SN76489 sn76489_;
Outputs::Speaker::LowpassSpeaker<TI::SN76489> speaker_;
std::vector<std::unique_ptr<Inputs::Joystick>> joysticks_;
HalfCycles time_since_vdp_update_;
HalfCycles time_since_sn76489_update_;
HalfCycles time_until_interrupt_;
uint8_t ram_[8*1024];
uint8_t bios_[8*1024];
std::vector<uint8_t> cartridge_;
// 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.
if(!(memory_control_ & 0x40)) {
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(static_cast<size_t>(0x4000), cartridge_.size() - start_addr),
c * 0x4000);
}
// The first 1kb doesn't page though.
map(read_pointers_, cartridge_.data(), 0x400, 0x0000);
} else {
map(read_pointers_, nullptr, 0xc000, 0x0000);
}
// Throw the BIOS on top if it isn't disabled.
if(!(memory_control_ & 0x08)) {
map(read_pointers_, bios_, 8*1024, 0);
}
}
};
}
}
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() {}