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CLK/Components/1770/1770.hpp
2020-01-19 20:05:22 -05:00

145 lines
4.2 KiB
C++

//
// 1770.hpp
// Clock Signal
//
// Created by Thomas Harte on 17/09/2016.
// Copyright 2016 Thomas Harte. All rights reserved.
//
#ifndef _770_hpp
#define _770_hpp
#include "../../Storage/Disk/Controller/MFMDiskController.hpp"
namespace WD {
/*!
Provides an emulation of various Western Digital drive controllers, including the
WD1770, WD1772, FDC1773 and FDC1793.
*/
class WD1770: public Storage::Disk::MFMController {
public:
enum Personality {
P1770, // implies automatic motor-on management, with Type 2 commands offering a spin-up disable
P1772, // as per the 1770, with different stepping rates
P1773, // implements the side number-testing logic of the 1793; omits spin-up/loading logic
P1793 // implies Type 2 commands use side number testing logic; spin-up/loading is by HLD and HLT
};
/*!
Constructs an instance of the drive controller that behaves according to personality @c p.
@param p The type of controller to emulate.
*/
WD1770(Personality p);
/// Sets the value of the double-density input; when @c is_double_density is @c true, reads and writes double-density format data.
using Storage::Disk::MFMController::set_is_double_density;
/// Writes @c value to the register at @c address. Only the low two bits of the address are decoded.
void write(int address, uint8_t value);
/// Fetches the value of the register @c address. Only the low two bits of the address are decoded.
uint8_t read(int address);
/// Runs the controller for @c number_of_cycles cycles.
void run_for(const Cycles cycles);
enum Flag: uint8_t {
NotReady = 0x80, // 0x80
MotorOn = 0x80,
WriteProtect = 0x40, // 0x40
RecordType = 0x20, // 0x20
SpinUp = 0x20,
HeadLoaded = 0x20,
RecordNotFound = 0x10, // 0x10
SeekError = 0x10,
CRCError = 0x08, // 0x08
LostData = 0x04, // 0x04
TrackZero = 0x04,
DataRequest = 0x02, // 0x02
Index = 0x02,
Busy = 0x01 // 0x01
};
/// @returns The current value of the IRQ line output.
inline bool get_interrupt_request_line() { return status_.interrupt_request; }
/// @returns The current value of the DRQ line output.
inline bool get_data_request_line() { return status_.data_request; }
class Delegate {
public:
virtual void wd1770_did_change_output(WD1770 *wd1770) = 0;
};
inline void set_delegate(Delegate *delegate) { delegate_ = delegate; }
ClockingHint::Preference preferred_clocking() final;
protected:
virtual void set_head_load_request(bool head_load);
virtual void set_motor_on(bool motor_on);
void set_head_loaded(bool head_loaded);
/// @returns The last value posted to @c set_head_loaded.
bool get_head_loaded();
private:
Personality personality_;
inline bool has_motor_on_line() { return (personality_ != P1793 ) && (personality_ != P1773); }
inline bool has_head_load_line() { return (personality_ == P1793 ); }
struct Status {
bool write_protect = false;
bool record_type = false;
bool spin_up = false;
bool record_not_found = false;
bool crc_error = false;
bool seek_error = false;
bool lost_data = false;
bool data_request = false;
bool interrupt_request = false;
bool busy = false;
bool track_zero = false;
enum {
One, Two, Three
} type = One;
} status_;
uint8_t track_;
uint8_t sector_;
uint8_t data_;
uint8_t command_;
int index_hole_count_;
int index_hole_count_target_ = -1;
int distance_into_section_;
int step_direction_;
void update_status(std::function<void(Status &)> updater);
// Events
enum Event1770: int {
Command = (1 << 3), // Indicates receipt of a new command.
HeadLoad = (1 << 4), // Indicates the head has been loaded (1973 only).
Timer = (1 << 5), // Indicates that the delay_time_-powered timer has timed out.
IndexHoleTarget = (1 << 6), // Indicates that index_hole_count_ has reached index_hole_count_target_.
ForceInterrupt = (1 << 7) // Indicates a forced interrupt.
};
void posit_event(int type);
int interesting_event_mask_;
int resume_point_ = 0;
Cycles::IntType delay_time_ = 0;
// ID buffer
uint8_t header_[6];
// 1793 head-loading logic
bool head_is_loaded_ = false;
// delegate
Delegate *delegate_ = nullptr;
};
}
#endif /* _770_hpp */