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