mirror of
https://github.com/TomHarte/CLK.git
synced 2024-07-05 10:28:58 +00:00
285 lines
7.5 KiB
C++
285 lines
7.5 KiB
C++
//
|
||
// Commodore1540.cpp
|
||
// Clock Signal
|
||
//
|
||
// Created by Thomas Harte on 05/07/2016.
|
||
// Copyright © 2016 Thomas Harte. All rights reserved.
|
||
//
|
||
|
||
#include "C1540.hpp"
|
||
#include <string>
|
||
#include "../../../Storage/Disk/Encodings/CommodoreGCR.hpp"
|
||
|
||
using namespace Commodore::C1540;
|
||
|
||
Machine::Machine() :
|
||
shift_register_(0),
|
||
Storage::Disk::Controller(1000000, 4, 300),
|
||
serial_port_(new SerialPort),
|
||
serial_port_VIA_(new SerialPortVIA)
|
||
{
|
||
// attach the serial port to its VIA and vice versa
|
||
serial_port_->set_serial_port_via(serial_port_VIA_);
|
||
serial_port_VIA_->set_serial_port(serial_port_);
|
||
|
||
// set this instance as the delegate to receive interrupt requests from both VIAs
|
||
serial_port_VIA_->set_interrupt_delegate(this);
|
||
drive_VIA_.set_interrupt_delegate(this);
|
||
drive_VIA_.set_delegate(this);
|
||
|
||
// set a bit rate
|
||
set_expected_bit_length(Storage::Encodings::CommodoreGCR::length_of_a_bit_in_time_zone(3));
|
||
}
|
||
|
||
void Machine::set_serial_bus(std::shared_ptr<::Commodore::Serial::Bus> serial_bus)
|
||
{
|
||
Commodore::Serial::AttachPortAndBus(serial_port_, serial_bus);
|
||
}
|
||
|
||
unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uint16_t address, uint8_t *value)
|
||
{
|
||
/*
|
||
Memory map (given that I'm unsure yet on any potential mirroring):
|
||
|
||
0x0000–0x07ff RAM
|
||
0x1800–0x180f the serial-port VIA
|
||
0x1c00–0x1c0f the drive VIA
|
||
0xc000–0xffff ROM
|
||
*/
|
||
if(address < 0x800)
|
||
{
|
||
if(isReadOperation(operation))
|
||
*value = ram_[address];
|
||
else
|
||
ram_[address] = *value;
|
||
}
|
||
else if(address >= 0xc000)
|
||
{
|
||
if(isReadOperation(operation))
|
||
*value = rom_[address & 0x3fff];
|
||
}
|
||
else if(address >= 0x1800 && address <= 0x180f)
|
||
{
|
||
if(isReadOperation(operation))
|
||
*value = serial_port_VIA_->get_register(address);
|
||
else
|
||
serial_port_VIA_->set_register(address, *value);
|
||
}
|
||
else if(address >= 0x1c00 && address <= 0x1c0f)
|
||
{
|
||
if(isReadOperation(operation))
|
||
*value = drive_VIA_.get_register(address);
|
||
else
|
||
drive_VIA_.set_register(address, *value);
|
||
}
|
||
|
||
serial_port_VIA_->run_for_cycles(1);
|
||
drive_VIA_.run_for_cycles(1);
|
||
|
||
return 1;
|
||
}
|
||
|
||
void Machine::set_rom(const uint8_t *rom)
|
||
{
|
||
memcpy(rom_, rom, sizeof(rom_));
|
||
}
|
||
|
||
void Machine::set_disk(std::shared_ptr<Storage::Disk::Disk> disk)
|
||
{
|
||
std::shared_ptr<Storage::Disk::Drive> drive(new Storage::Disk::Drive);
|
||
drive->set_disk(disk);
|
||
set_drive(drive);
|
||
}
|
||
|
||
void Machine::run_for_cycles(int number_of_cycles)
|
||
{
|
||
CPU6502::Processor<Machine>::run_for_cycles(number_of_cycles);
|
||
set_motor_on(drive_VIA_.get_motor_enabled());
|
||
if(drive_VIA_.get_motor_enabled()) // TODO: motor speed up/down
|
||
Storage::Disk::Controller::run_for_cycles(number_of_cycles);
|
||
}
|
||
|
||
#pragma mark - 6522 delegate
|
||
|
||
void Machine::mos6522_did_change_interrupt_status(void *mos6522)
|
||
{
|
||
// both VIAs are connected to the IRQ line
|
||
set_irq_line(serial_port_VIA_->get_interrupt_line() || drive_VIA_.get_interrupt_line());
|
||
}
|
||
|
||
#pragma mark - Disk drive
|
||
|
||
void Machine::process_input_bit(int value, unsigned int cycles_since_index_hole)
|
||
{
|
||
shift_register_ = (shift_register_ << 1) | value;
|
||
if((shift_register_ & 0x3ff) == 0x3ff)
|
||
{
|
||
drive_VIA_.set_sync_detected(true);
|
||
bit_window_offset_ = -1; // i.e. this bit isn't the first within a data window, but the next might be
|
||
}
|
||
else
|
||
{
|
||
drive_VIA_.set_sync_detected(false);
|
||
}
|
||
bit_window_offset_++;
|
||
if(bit_window_offset_ == 8)
|
||
{
|
||
drive_VIA_.set_data_input((uint8_t)shift_register_);
|
||
bit_window_offset_ = 0;
|
||
if(drive_VIA_.get_should_set_overflow())
|
||
{
|
||
set_overflow_line(true);
|
||
}
|
||
}
|
||
else
|
||
set_overflow_line(false);
|
||
}
|
||
|
||
// the 1540 does not recognise index holes
|
||
void Machine::process_index_hole() {}
|
||
|
||
#pragma mak - Drive VIA delegate
|
||
|
||
void Machine::drive_via_did_step_head(void *driveVIA, int direction)
|
||
{
|
||
step(direction);
|
||
}
|
||
|
||
void Machine::drive_via_did_set_data_density(void *driveVIA, int density)
|
||
{
|
||
set_expected_bit_length(Storage::Encodings::CommodoreGCR::length_of_a_bit_in_time_zone((unsigned int)density));
|
||
}
|
||
|
||
#pragma mark - SerialPortVIA
|
||
|
||
SerialPortVIA::SerialPortVIA() :
|
||
port_b_(0x00), attention_acknowledge_level_(false), attention_level_input_(true), data_level_output_(false)
|
||
{}
|
||
|
||
uint8_t SerialPortVIA::get_port_input(Port port)
|
||
{
|
||
if(port) return port_b_;
|
||
return 0xff;
|
||
}
|
||
|
||
void SerialPortVIA::set_port_output(Port port, uint8_t value, uint8_t mask)
|
||
{
|
||
if(port)
|
||
{
|
||
std::shared_ptr<::Commodore::Serial::Port> serialPort = serial_port_.lock();
|
||
if(serialPort) {
|
||
attention_acknowledge_level_ = !(value&0x10);
|
||
data_level_output_ = (value&0x02);
|
||
|
||
serialPort->set_output(::Commodore::Serial::Line::Clock, (::Commodore::Serial::LineLevel)!(value&0x08));
|
||
update_data_line();
|
||
}
|
||
}
|
||
}
|
||
|
||
void SerialPortVIA::set_serial_line_state(::Commodore::Serial::Line line, bool value)
|
||
{
|
||
switch(line)
|
||
{
|
||
default: break;
|
||
case ::Commodore::Serial::Line::Data: port_b_ = (port_b_ & ~0x01) | (value ? 0x00 : 0x01); break;
|
||
case ::Commodore::Serial::Line::Clock: port_b_ = (port_b_ & ~0x04) | (value ? 0x00 : 0x04); break;
|
||
case ::Commodore::Serial::Line::Attention:
|
||
attention_level_input_ = !value;
|
||
port_b_ = (port_b_ & ~0x80) | (value ? 0x00 : 0x80);
|
||
set_control_line_input(Port::A, Line::One, !value);
|
||
update_data_line();
|
||
break;
|
||
}
|
||
}
|
||
|
||
void SerialPortVIA::set_serial_port(const std::shared_ptr<::Commodore::Serial::Port> &serialPort)
|
||
{
|
||
serial_port_ = serialPort;
|
||
}
|
||
|
||
void SerialPortVIA::update_data_line()
|
||
{
|
||
std::shared_ptr<::Commodore::Serial::Port> serialPort = serial_port_.lock();
|
||
if(serialPort)
|
||
{
|
||
// "ATN (Attention) is an input on pin 3 of P2 and P3 that is sensed at PB7 and CA1 of UC3 after being inverted by UA1"
|
||
serialPort->set_output(::Commodore::Serial::Line::Data,
|
||
(::Commodore::Serial::LineLevel)(!data_level_output_ && (attention_level_input_ != attention_acknowledge_level_)));
|
||
}
|
||
}
|
||
|
||
#pragma mark - DriveVIA
|
||
|
||
void DriveVIA::set_delegate(Delegate *delegate)
|
||
{
|
||
delegate_ = delegate;
|
||
}
|
||
|
||
// write protect tab uncovered
|
||
DriveVIA::DriveVIA() : port_b_(0xff), port_a_(0xff), delegate_(nullptr) {}
|
||
|
||
uint8_t DriveVIA::get_port_input(Port port) {
|
||
return port ? port_b_ : port_a_;
|
||
}
|
||
|
||
void DriveVIA::set_sync_detected(bool sync_detected) {
|
||
port_b_ = (port_b_ & 0x7f) | (sync_detected ? 0x00 : 0x80);
|
||
}
|
||
|
||
void DriveVIA::set_data_input(uint8_t value) {
|
||
port_a_ = value;
|
||
}
|
||
|
||
bool DriveVIA::get_should_set_overflow() {
|
||
return should_set_overflow_;
|
||
}
|
||
|
||
bool DriveVIA::get_motor_enabled() {
|
||
return drive_motor_;
|
||
}
|
||
|
||
void DriveVIA::set_control_line_output(Port port, Line line, bool value) {
|
||
if(port == Port::A && line == Line::Two) {
|
||
should_set_overflow_ = value;
|
||
}
|
||
}
|
||
|
||
void DriveVIA::set_port_output(Port port, uint8_t value, uint8_t direction_mask) {
|
||
if(port)
|
||
{
|
||
// record drive motor state
|
||
drive_motor_ = !!(value&4);
|
||
|
||
// check for a head step
|
||
int step_difference = ((value&3) - (previous_port_b_output_&3))&3;
|
||
if(step_difference)
|
||
{
|
||
if(delegate_) delegate_->drive_via_did_step_head(this, (step_difference == 1) ? 1 : -1);
|
||
}
|
||
|
||
// check for a change in density
|
||
int density_difference = (previous_port_b_output_^value) & (3 << 5);
|
||
if(density_difference && delegate_)
|
||
{
|
||
delegate_->drive_via_did_set_data_density(this, (value >> 5)&3);
|
||
}
|
||
|
||
// TODO: something with the drive LED
|
||
// printf("LED: %s\n", value&8 ? "On" : "Off");
|
||
|
||
previous_port_b_output_ = value;
|
||
}
|
||
}
|
||
|
||
#pragma mark - SerialPort
|
||
|
||
void SerialPort::set_input(::Commodore::Serial::Line line, ::Commodore::Serial::LineLevel level) {
|
||
std::shared_ptr<SerialPortVIA> serialPortVIA = serial_port_VIA_.lock();
|
||
if(serialPortVIA) serialPortVIA->set_serial_line_state(line, (bool)level);
|
||
}
|
||
|
||
void SerialPort::set_serial_port_via(const std::shared_ptr<SerialPortVIA> &serialPortVIA) {
|
||
serial_port_VIA_ = serialPortVIA;
|
||
}
|