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Hopefully to eliminate a lot of unnecessary `Time` work; inaccuracies should still be within tolerable range.
78 lines
1.6 KiB
C++
78 lines
1.6 KiB
C++
//
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// IWM.hpp
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// Clock Signal
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//
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// Created by Thomas Harte on 05/05/2019.
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// Copyright © 2019 Thomas Harte. All rights reserved.
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//
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#ifndef IWM_hpp
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#define IWM_hpp
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#include "../../ClockReceiver/ClockReceiver.hpp"
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#include "../../Storage/Disk/Drive.hpp"
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#include <cstdint>
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namespace Apple {
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class IWM:
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public Storage::Disk::Drive::EventDelegate {
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public:
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IWM(int clock_rate);
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/// Sets the current external value of the data bus.
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void write(int address, uint8_t value);
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/*!
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Submits an access to address @c address.
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@returns The 8-bit value loaded to the data bus by the IWM.
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*/
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uint8_t read(int address);
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/*!
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Sets the current input of the IWM's SEL line.
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*/
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void set_select(bool enabled);
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/// Advances the controller by @c cycles.
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void run_for(const Cycles cycles);
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/// Connects a drive to the IWM.
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void set_drive(int slot, Storage::Disk::Drive *drive);
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private:
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// Storage::Disk::Drive::EventDelegate.
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void process_event(const Storage::Disk::Drive::Event &event) override;
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const int clock_rate_;
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uint8_t data_register_ = 0;
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uint8_t mode_ = 0;
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bool read_write_ready_ = true;
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bool write_overran_ = false;
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int state_ = 0;
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int active_drive_ = 0;
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Storage::Disk::Drive *drives_[2] = {nullptr, nullptr};
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bool drive_motor_on_ = false;
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Cycles cycles_until_motor_off_;
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void access(int address);
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uint8_t shift_register_ = 0;
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void propose_shift(uint8_t bit);
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Cycles cycles_since_shift_;
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Cycles bit_length_;
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int step_direction_ = 0; // TODO: this should live on the drive.
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};
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}
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#endif /* IWM_hpp */
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