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CLK/Machines/ColecoVision/ColecoVision.cpp
2019-02-24 22:37:24 -05:00

413 lines
12 KiB
C++

//
// ColecoVision.cpp
// Clock Signal
//
// Created by Thomas Harte on 23/02/2018.
// Copyright 2018 Thomas Harte. All rights reserved.
//
#include "ColecoVision.hpp"
#include "../../Processors/Z80/Z80.hpp"
#include "../../Components/9918/9918.hpp"
#include "../../Components/AY38910/AY38910.hpp" // For the Super Game Module.
#include "../../Components/SN76489/SN76489.hpp"
#include "../CRTMachine.hpp"
#include "../JoystickMachine.hpp"
#include "../../ClockReceiver/ForceInline.hpp"
#include "../../Outputs/Speaker/Implementation/CompoundSource.hpp"
#include "../../Outputs/Speaker/Implementation/LowpassSpeaker.hpp"
#include "../../Analyser/Dynamic/ConfidenceCounter.hpp"
namespace {
const int sn76489_divider = 2;
}
namespace Coleco {
namespace Vision {
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),
Input('0'), Input('1'), Input('2'),
Input('3'), Input('4'), Input('5'),
Input('6'), Input('7'), Input('8'),
Input('9'), Input('*'), Input('#'),
}) {}
void did_set_input(const Input &digital_input, bool is_active) override {
switch(digital_input.type) {
default: return;
case Input::Key:
if(!is_active) keypad_ |= 0xf;
else {
uint8_t mask = 0xf;
switch(digital_input.info.key.symbol) {
case '8': mask = 0x1; break;
case '4': mask = 0x2; break;
case '5': mask = 0x3; break;
case '7': mask = 0x5; break;
case '#': mask = 0x6; break;
case '2': mask = 0x7; break;
case '*': mask = 0x9; break;
case '0': mask = 0xa; break;
case '9': mask = 0xb; break;
case '3': mask = 0xc; break;
case '1': mask = 0xd; break;
case '6': mask = 0xe; break;
default: break;
}
keypad_ = (keypad_ & 0xf0) | mask;
}
break;
case Input::Up: if(is_active) direction_ &= ~0x01; else direction_ |= 0x01; break;
case Input::Right: if(is_active) direction_ &= ~0x02; else direction_ |= 0x02; break;
case Input::Down: if(is_active) direction_ &= ~0x04; else direction_ |= 0x04; break;
case Input::Left: if(is_active) direction_ &= ~0x08; else direction_ |= 0x08; break;
case Input::Fire:
switch(digital_input.info.control.index) {
default: break;
case 0: if(is_active) direction_ &= ~0x40; else direction_ |= 0x40; break;
case 1: if(is_active) keypad_ &= ~0x40; else keypad_ |= 0x40; break;
}
break;
}
}
uint8_t get_direction_input() {
return direction_;
}
uint8_t get_keypad_input() {
return keypad_;
}
private:
uint8_t direction_ = 0xff;
uint8_t keypad_ = 0x7f;
};
class ConcreteMachine:
public Machine,
public CPU::Z80::BusHandler,
public CRTMachine::Machine,
public JoystickMachine::Machine {
public:
ConcreteMachine(const Analyser::Static::Target &target, const ROMMachine::ROMFetcher &rom_fetcher) :
z80_(*this),
vdp_(TI::TMS::TMS9918A),
sn76489_(TI::SN76489::Personality::SN76489, audio_queue_, sn76489_divider),
ay_(audio_queue_),
mixer_(sn76489_, ay_),
speaker_(mixer_) {
speaker_.set_input_rate(3579545.0f / static_cast<float>(sn76489_divider));
set_clock_rate(3579545);
joysticks_.emplace_back(new Joystick);
joysticks_.emplace_back(new Joystick);
const auto roms = rom_fetcher(
"ColecoVision",
{ "coleco.rom" });
if(!roms[0]) {
throw ROMMachine::Error::MissingROMs;
}
bios_ = *roms[0];
bios_.resize(8192);
if(!target.media.cartridges.empty()) {
const auto &segment = target.media.cartridges.front()->get_segments().front();
cartridge_ = segment.data;
if(cartridge_.size() >= 32768)
cartridge_address_limit_ = 0xffff;
else
cartridge_address_limit_ = static_cast<uint16_t>(0x8000 + cartridge_.size() - 1);
if(cartridge_.size() > 32768) {
// Ensure the cartrige is a multiple of 16kb in size, as that won't
// be checked when paging.
const size_t extension = (16384 - (cartridge_.size() & 16383)) % 16384;
cartridge_.resize(cartridge_.size() + extension);
cartridge_pages_[0] = &cartridge_[cartridge_.size() - 16384];
cartridge_pages_[1] = cartridge_.data();
is_megacart_ = true;
} else {
// Ensure at least 32kb is allocated to the cartrige so that
// reads are never out of bounds.
cartridge_.resize(32768);
cartridge_pages_[0] = cartridge_.data();
cartridge_pages_[1] = cartridge_.data() + 16384;
is_megacart_ = false;
}
}
// ColecoVisions have composite output only.
vdp_.set_display_type(Outputs::Display::DisplayType::CompositeColour);
}
~ConcreteMachine() {
audio_queue_.flush();
}
std::vector<std::unique_ptr<Inputs::Joystick>> &get_joysticks() override {
return joysticks_;
}
void set_scan_target(Outputs::Display::ScanTarget *scan_target) override {
vdp_.set_scan_target(scan_target);
}
void set_display_type(Outputs::Display::DisplayType display_type) override {
vdp_.set_display_type(display_type);
}
Outputs::Speaker::Speaker *get_speaker() override {
return &speaker_;
}
void run_for(const Cycles cycles) override {
z80_.run_for(cycles);
}
// MARK: Z80::BusHandler
forceinline HalfCycles perform_machine_cycle(const CPU::Z80::PartialMachineCycle &cycle) {
// The SN76489 will use its ready line to trigger the Z80's wait for three
// cycles when accessed. Everything else runs at full speed. Short-circuit
// that whole piece of communications by just accruing the time here if applicable.
const HalfCycles penalty(
(
cycle.operation == CPU::Z80::PartialMachineCycle::Output &&
((*cycle.address >> 5) & 7) == 7
) ? 6 : 0
);
const HalfCycles length = cycle.length + penalty;
time_since_vdp_update_ += length;
time_since_sn76489_update_ += length;
// Act only if necessary.
if(cycle.is_terminal()) {
uint16_t address = cycle.address ? *cycle.address : 0x0000;
switch(cycle.operation) {
case CPU::Z80::PartialMachineCycle::ReadOpcode:
if(!address) pc_zero_accesses_++;
case CPU::Z80::PartialMachineCycle::Read:
if(address < 0x2000) {
if(super_game_module_.replace_bios) {
*cycle.value = super_game_module_.ram[address];
} else {
*cycle.value = bios_[address];
}
} else if(super_game_module_.replace_ram && address < 0x8000) {
*cycle.value = super_game_module_.ram[address];
} else if(address >= 0x6000 && address < 0x8000) {
*cycle.value = ram_[address & 1023];
} else if(address >= 0x8000 && address <= cartridge_address_limit_) {
if(is_megacart_ && address >= 0xffc0) {
page_megacart(address);
}
*cycle.value = cartridge_pages_[(address >> 14)&1][address&0x3fff];
} else {
*cycle.value = 0xff;
}
break;
case CPU::Z80::PartialMachineCycle::Write:
if(super_game_module_.replace_bios && address < 0x2000) {
super_game_module_.ram[address] = *cycle.value;
} else if(super_game_module_.replace_ram && address >= 0x2000 && address < 0x8000) {
super_game_module_.ram[address] = *cycle.value;
} else if(address >= 0x6000 && address < 0x8000) {
ram_[address & 1023] = *cycle.value;
} else if(is_megacart_ && address >= 0xffc0) {
page_megacart(address);
}
break;
case CPU::Z80::PartialMachineCycle::Input:
switch((address >> 5) & 7) {
case 5:
update_video();
*cycle.value = vdp_.get_register(address);
z80_.set_non_maskable_interrupt_line(vdp_.get_interrupt_line());
time_until_interrupt_ = vdp_.get_time_until_interrupt();
break;
case 7: {
const std::size_t joystick_id = (address&2) >> 1;
Joystick *joystick = static_cast<Joystick *>(joysticks_[joystick_id].get());
if(joysticks_in_keypad_mode_) {
*cycle.value = joystick->get_keypad_input();
} else {
*cycle.value = joystick->get_direction_input();
}
// Hitting exactly the recommended joypad input port is an indicator that
// this really is a ColecoVision game. The BIOS won't do this when just waiting
// to start a game (unlike accessing the VDP and SN).
if((address&0xfc) == 0xfc) confidence_counter_.add_hit();
} break;
default:
switch(address&0xff) {
default: *cycle.value = 0xff; break;
case 0x52:
// Read AY data.
update_audio();
ay_.set_control_lines(GI::AY38910::ControlLines(GI::AY38910::BC2 | GI::AY38910::BC1));
*cycle.value = ay_.get_data_output();
ay_.set_control_lines(GI::AY38910::ControlLines(0));
break;
}
break;
}
break;
case CPU::Z80::PartialMachineCycle::Output: {
const int eighth = (address >> 5) & 7;
switch(eighth) {
case 4: case 6:
joysticks_in_keypad_mode_ = eighth == 4;
break;
case 5:
update_video();
vdp_.set_register(address, *cycle.value);
z80_.set_non_maskable_interrupt_line(vdp_.get_interrupt_line());
time_until_interrupt_ = vdp_.get_time_until_interrupt();
break;
case 7:
update_audio();
sn76489_.set_register(*cycle.value);
break;
default:
// Catch Super Game Module accesses; it decodes more thoroughly.
switch(address&0xff) {
default: break;
case 0x7f:
super_game_module_.replace_bios = !((*cycle.value)&0x2);
break;
case 0x50:
// Set AY address.
update_audio();
ay_.set_control_lines(GI::AY38910::BC1);
ay_.set_data_input(*cycle.value);
ay_.set_control_lines(GI::AY38910::ControlLines(0));
break;
case 0x51:
// Set AY data.
update_audio();
ay_.set_control_lines(GI::AY38910::ControlLines(GI::AY38910::BC2 | GI::AY38910::BDIR));
ay_.set_data_input(*cycle.value);
ay_.set_control_lines(GI::AY38910::ControlLines(0));
break;
case 0x53:
super_game_module_.replace_ram = !!((*cycle.value)&0x1);
break;
}
break;
}
} break;
default: break;
}
}
if(time_until_interrupt_ > 0) {
time_until_interrupt_ -= length;
if(time_until_interrupt_ <= HalfCycles(0)) {
z80_.set_non_maskable_interrupt_line(true, time_until_interrupt_);
}
}
return penalty;
}
void flush() {
update_video();
update_audio();
audio_queue_.perform();
}
float get_confidence() override {
if(pc_zero_accesses_ > 1) return 0.0f;
return confidence_counter_.get_confidence();
}
private:
inline void page_megacart(uint16_t address) {
const std::size_t selected_start = (static_cast<std::size_t>(address&63) << 14) % cartridge_.size();
cartridge_pages_[1] = &cartridge_[selected_start];
}
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());
}
CPU::Z80::Processor<ConcreteMachine, false, false> z80_;
TI::TMS::TMS9918 vdp_;
Concurrency::DeferringAsyncTaskQueue audio_queue_;
TI::SN76489 sn76489_;
GI::AY38910::AY38910 ay_;
Outputs::Speaker::CompoundSource<TI::SN76489, GI::AY38910::AY38910> mixer_;
Outputs::Speaker::LowpassSpeaker<Outputs::Speaker::CompoundSource<TI::SN76489, GI::AY38910::AY38910>> speaker_;
std::vector<uint8_t> bios_;
std::vector<uint8_t> cartridge_;
uint8_t *cartridge_pages_[2];
uint8_t ram_[1024];
bool is_megacart_ = false;
uint16_t cartridge_address_limit_ = 0;
struct {
bool replace_bios = false;
bool replace_ram = false;
uint8_t ram[32768];
} super_game_module_;
std::vector<std::unique_ptr<Inputs::Joystick>> joysticks_;
bool joysticks_in_keypad_mode_ = false;
HalfCycles time_since_vdp_update_;
HalfCycles time_since_sn76489_update_;
HalfCycles time_until_interrupt_;
Analyser::Dynamic::ConfidenceCounter confidence_counter_;
int pc_zero_accesses_ = 0;
};
}
}
using namespace Coleco::Vision;
Machine *Machine::ColecoVision(const Analyser::Static::Target *target, const ROMMachine::ROMFetcher &rom_fetcher) {
return new ConcreteMachine(*target, rom_fetcher);
}
Machine::~Machine() {}