mirror of
https://github.com/TomHarte/CLK.git
synced 2024-12-26 09:29:45 +00:00
198 lines
7.0 KiB
C++
198 lines
7.0 KiB
C++
//
|
|
// Cartridge.h
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 17/03/2017.
|
|
// Copyright © 2017 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#ifndef Atari2600_Cartridge_hpp
|
|
#define Atari2600_Cartridge_hpp
|
|
|
|
#include "../../../Processors/6502/6502.hpp"
|
|
#include "../Bus.hpp"
|
|
|
|
namespace Atari2600 {
|
|
namespace Cartridge {
|
|
|
|
class BusExtender: public CPU::MOS6502::BusHandler {
|
|
public:
|
|
BusExtender(uint8_t *rom_base, std::size_t rom_size) : rom_base_(rom_base), rom_size_(rom_size) {}
|
|
|
|
void advance_cycles(int cycles) {}
|
|
|
|
protected:
|
|
uint8_t *rom_base_;
|
|
std::size_t rom_size_;
|
|
};
|
|
|
|
template<class T> class Cartridge:
|
|
public CPU::MOS6502::BusHandler,
|
|
public Bus {
|
|
|
|
public:
|
|
Cartridge(const std::vector<uint8_t> &rom) :
|
|
m6502_(*this),
|
|
rom_(rom),
|
|
bus_extender_(rom_.data(), rom.size()) {
|
|
// The above works because bus_extender_ is declared after rom_ in the instance storage list;
|
|
// consider doing something less fragile.
|
|
}
|
|
|
|
void run_for(const Cycles cycles) { m6502_.run_for(cycles); }
|
|
void set_reset_line(bool state) { m6502_.set_reset_line(state); }
|
|
|
|
// to satisfy CPU::MOS6502::Processor
|
|
Cycles perform_bus_operation(CPU::MOS6502::BusOperation operation, uint16_t address, uint8_t *value) {
|
|
uint8_t returnValue = 0xff;
|
|
int cycles_run_for = 3;
|
|
|
|
// this occurs as a feedback loop — the 2600 requests ready, then performs the cycles_run_for
|
|
// leap to the end of ready only once ready is signalled — because on a 6502 ready doesn't take
|
|
// effect until the next read; therefore it isn't safe to assume that signalling ready immediately
|
|
// skips to the end of the line.
|
|
if(operation == CPU::MOS6502::BusOperation::Ready)
|
|
cycles_run_for = tia_->get_cycles_until_horizontal_blank(cycles_since_video_update_);
|
|
|
|
cycles_since_speaker_update_ += Cycles(cycles_run_for);
|
|
cycles_since_video_update_ += Cycles(cycles_run_for);
|
|
cycles_since_6532_update_ += Cycles(cycles_run_for / 3);
|
|
bus_extender_.advance_cycles(cycles_run_for / 3);
|
|
|
|
if(operation != CPU::MOS6502::BusOperation::Ready) {
|
|
// give the cartridge a chance to respond to the bus access
|
|
bus_extender_.perform_bus_operation(operation, address, value);
|
|
|
|
// check for a RIOT RAM access
|
|
if((address&0x1280) == 0x80) {
|
|
if(isReadOperation(operation)) {
|
|
returnValue &= mos6532_.get_ram(address);
|
|
} else {
|
|
mos6532_.set_ram(address, *value);
|
|
}
|
|
}
|
|
|
|
// check for a TIA access
|
|
if(!(address&0x1080)) {
|
|
if(isReadOperation(operation)) {
|
|
const uint16_t decodedAddress = address & 0xf;
|
|
switch(decodedAddress) {
|
|
case 0x00: // missile 0 / player collisions
|
|
case 0x01: // missile 1 / player collisions
|
|
case 0x02: // player 0 / playfield / ball collisions
|
|
case 0x03: // player 1 / playfield / ball collisions
|
|
case 0x04: // missile 0 / playfield / ball collisions
|
|
case 0x05: // missile 1 / playfield / ball collisions
|
|
case 0x06: // ball / playfield collisions
|
|
case 0x07: // player / player, missile / missile collisions
|
|
returnValue &= tia_->get_collision_flags(decodedAddress);
|
|
break;
|
|
|
|
case 0x08:
|
|
case 0x09:
|
|
case 0x0a:
|
|
case 0x0b:
|
|
// TODO: pot ports
|
|
returnValue &= 0;
|
|
break;
|
|
|
|
case 0x0c:
|
|
case 0x0d:
|
|
returnValue &= tia_input_value_[decodedAddress - 0x0c];
|
|
break;
|
|
}
|
|
} else {
|
|
const uint16_t decodedAddress = address & 0x3f;
|
|
switch(decodedAddress) {
|
|
case 0x00: update_video(); tia_->set_sync(*value & 0x02); break;
|
|
case 0x01: update_video(); tia_->set_blank(*value & 0x02); break;
|
|
|
|
case 0x02: m6502_.set_ready_line(true); break;
|
|
case 0x03: update_video(); tia_->reset_horizontal_counter(); break;
|
|
// TODO: audio will now be out of synchronisation — fix
|
|
|
|
case 0x04:
|
|
case 0x05: update_video(); tia_->set_player_number_and_size(decodedAddress - 0x04, *value); break;
|
|
case 0x06:
|
|
case 0x07: update_video(); tia_->set_player_missile_colour(decodedAddress - 0x06, *value); break;
|
|
case 0x08: update_video(); tia_->set_playfield_ball_colour(*value); break;
|
|
case 0x09: update_video(); tia_->set_background_colour(*value); break;
|
|
case 0x0a: update_video(); tia_->set_playfield_control_and_ball_size(*value); break;
|
|
case 0x0b:
|
|
case 0x0c: update_video(); tia_->set_player_reflected(decodedAddress - 0x0b, !((*value)&8)); break;
|
|
case 0x0d:
|
|
case 0x0e:
|
|
case 0x0f: update_video(); tia_->set_playfield(decodedAddress - 0x0d, *value); break;
|
|
case 0x10:
|
|
case 0x11: update_video(); tia_->set_player_position(decodedAddress - 0x10); break;
|
|
case 0x12:
|
|
case 0x13: update_video(); tia_->set_missile_position(decodedAddress - 0x12); break;
|
|
case 0x14: update_video(); tia_->set_ball_position(); break;
|
|
case 0x1b:
|
|
case 0x1c: update_video(); tia_->set_player_graphic(decodedAddress - 0x1b, *value); break;
|
|
case 0x1d:
|
|
case 0x1e: update_video(); tia_->set_missile_enable(decodedAddress - 0x1d, (*value)&2); break;
|
|
case 0x1f: update_video(); tia_->set_ball_enable((*value)&2); break;
|
|
case 0x20:
|
|
case 0x21: update_video(); tia_->set_player_motion(decodedAddress - 0x20, *value); break;
|
|
case 0x22:
|
|
case 0x23: update_video(); tia_->set_missile_motion(decodedAddress - 0x22, *value); break;
|
|
case 0x24: update_video(); tia_->set_ball_motion(*value); break;
|
|
case 0x25:
|
|
case 0x26: tia_->set_player_delay(decodedAddress - 0x25, (*value)&1); break;
|
|
case 0x27: tia_->set_ball_delay((*value)&1); break;
|
|
case 0x28:
|
|
case 0x29: update_video(); tia_->set_missile_position_to_player(decodedAddress - 0x28, (*value)&2); break;
|
|
case 0x2a: update_video(); tia_->move(); break;
|
|
case 0x2b: update_video(); tia_->clear_motion(); break;
|
|
case 0x2c: update_video(); tia_->clear_collision_flags(); break;
|
|
|
|
case 0x15:
|
|
case 0x16: update_audio(); speaker_->set_control(decodedAddress - 0x15, *value); break;
|
|
case 0x17:
|
|
case 0x18: update_audio(); speaker_->set_divider(decodedAddress - 0x17, *value); break;
|
|
case 0x19:
|
|
case 0x1a: update_audio(); speaker_->set_volume(decodedAddress - 0x19, *value); break;
|
|
}
|
|
}
|
|
}
|
|
|
|
// check for a PIA access
|
|
if((address&0x1280) == 0x280) {
|
|
update_6532();
|
|
if(isReadOperation(operation)) {
|
|
returnValue &= mos6532_.get_register(address);
|
|
} else {
|
|
mos6532_.set_register(address, *value);
|
|
}
|
|
}
|
|
|
|
if(isReadOperation(operation)) {
|
|
*value &= returnValue;
|
|
}
|
|
}
|
|
|
|
if(!tia_->get_cycles_until_horizontal_blank(cycles_since_video_update_)) m6502_.set_ready_line(false);
|
|
|
|
return Cycles(cycles_run_for / 3);
|
|
}
|
|
|
|
void flush() {
|
|
update_audio();
|
|
update_video();
|
|
speaker_->flush();
|
|
}
|
|
|
|
protected:
|
|
CPU::MOS6502::Processor<Cartridge<T>, true> m6502_;
|
|
std::vector<uint8_t> rom_;
|
|
|
|
private:
|
|
T bus_extender_;
|
|
};
|
|
|
|
}
|
|
}
|
|
|
|
#endif /* Atari2600_Cartridge_hpp */
|