mirror of
https://github.com/TomHarte/CLK.git
synced 2024-06-09 01:29:44 +00:00
122 lines
2.9 KiB
C++
122 lines
2.9 KiB
C++
//
|
|
// IWM.hpp
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 05/05/2019.
|
|
// Copyright © 2019 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#pragma once
|
|
|
|
#include "../../Activity/Observer.hpp"
|
|
|
|
#include "../../ClockReceiver/ClockReceiver.hpp"
|
|
#include "../../ClockReceiver/ClockingHintSource.hpp"
|
|
|
|
#include "../../Storage/Disk/Drive.hpp"
|
|
|
|
#include <cstdint>
|
|
|
|
namespace Apple {
|
|
|
|
/*!
|
|
Defines the drive interface used by the IWM, derived from the external pinout as
|
|
per e.g. https://old.pinouts.ru/HD/MacExtDrive_pinout.shtml
|
|
|
|
These are subclasses of Storage::Disk::Drive, so accept any disk the emulator supports,
|
|
and provide the usual read/write interface for on-disk data.
|
|
*/
|
|
struct IWMDrive: public Storage::Disk::Drive {
|
|
IWMDrive(int input_clock_rate, int number_of_heads) : Storage::Disk::Drive(input_clock_rate, number_of_heads) {}
|
|
|
|
enum Line: int {
|
|
CA0 = 1 << 0,
|
|
CA1 = 1 << 1,
|
|
CA2 = 1 << 2,
|
|
LSTRB = 1 << 3,
|
|
SEL = 1 << 4,
|
|
};
|
|
|
|
virtual void set_enabled(bool) = 0;
|
|
virtual void set_control_lines(int) = 0;
|
|
virtual bool read() = 0;
|
|
};
|
|
|
|
class IWM:
|
|
public Storage::Disk::Drive::EventDelegate,
|
|
public ClockingHint::Observer {
|
|
public:
|
|
IWM(int clock_rate);
|
|
|
|
/// Sets the current external value of the data bus.
|
|
void write(int address, uint8_t value);
|
|
|
|
/*!
|
|
Submits an access to address @c address.
|
|
|
|
@returns The 8-bit value loaded to the data bus by the IWM.
|
|
*/
|
|
uint8_t read(int address);
|
|
|
|
/*!
|
|
Sets the current input of the IWM's SEL line.
|
|
*/
|
|
void set_select(bool enabled);
|
|
|
|
/// Advances the controller by @c cycles.
|
|
void run_for(const Cycles cycles);
|
|
|
|
/// Connects a drive to the IWM.
|
|
void set_drive(int slot, IWMDrive *drive);
|
|
|
|
/// Registers the currently-connected drives as @c Activity::Sources ;
|
|
/// the first will be declared 'Internal', the second 'External'.
|
|
void set_activity_observer(Activity::Observer *observer);
|
|
|
|
private:
|
|
// Storage::Disk::Drive::EventDelegate.
|
|
void process_event(const Storage::Disk::Drive::Event &event) final;
|
|
|
|
const int clock_rate_;
|
|
|
|
uint8_t data_register_ = 0;
|
|
uint8_t mode_ = 0;
|
|
// These related to functionality not-yet implemented.
|
|
// bool read_write_ready_ = true;
|
|
// bool write_overran_ = false;
|
|
|
|
int state_ = 0;
|
|
|
|
int active_drive_ = 0;
|
|
IWMDrive *drives_[2] = {nullptr, nullptr};
|
|
bool drive_is_rotating_[2] = {false, false};
|
|
|
|
void set_component_prefers_clocking(ClockingHint::Source *component, ClockingHint::Preference clocking) final;
|
|
|
|
Cycles cycles_until_disable_;
|
|
uint8_t write_handshake_ = 0x80;
|
|
|
|
void access(int address);
|
|
|
|
uint8_t shift_register_ = 0;
|
|
uint8_t next_output_ = 0;
|
|
int output_bits_remaining_ = 0;
|
|
|
|
void propose_shift(uint8_t bit);
|
|
Cycles cycles_since_shift_;
|
|
Cycles bit_length_ = Cycles(16);
|
|
|
|
void push_drive_state();
|
|
|
|
enum class ShiftMode {
|
|
Reading,
|
|
Writing,
|
|
CheckingWriteProtect
|
|
} shift_mode_;
|
|
|
|
uint8_t sense();
|
|
void select_shift_mode();
|
|
};
|
|
|
|
}
|