1
0
mirror of https://github.com/TomHarte/CLK.git synced 2024-12-24 12:30:17 +00:00
CLK/Components/DiskII/IWM.hpp
Thomas Harte 96005261c7 Adds activity lights for Macintosh disk activity.
Prompting a quick fix to drives not spinning down.
2019-08-02 16:26:23 -04:00

125 lines
2.8 KiB
C++

//
// IWM.hpp
// Clock Signal
//
// Created by Thomas Harte on 05/05/2019.
// Copyright © 2019 Thomas Harte. All rights reserved.
//
#ifndef IWM_hpp
#define IWM_hpp
#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 subclassed 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) override;
const int clock_rate_;
uint8_t data_register_ = 0;
uint8_t mode_ = 0;
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) override;
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();
};
}
#endif /* IWM_hpp */