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CLK/Components/DiskII/DiskIIDrive.cpp
2021-02-14 21:03:54 -05:00

46 lines
1.4 KiB
C++

//
// DiskIIDrive.cpp
// Clock Signal
//
// Created by Thomas Harte on 20/11/2020.
// Copyright © 2020 Thomas Harte. All rights reserved.
//
#include "DiskIIDrive.hpp"
using namespace Apple::Disk;
DiskIIDrive::DiskIIDrive(int input_clock_rate) :
IWMDrive(input_clock_rate, 1) {
Drive::set_rotation_speed(300.0f);
}
void DiskIIDrive::set_enabled(bool enabled) {
set_motor_on(enabled);
}
void DiskIIDrive::set_control_lines(int lines) {
// If the stepper magnet selections have changed, and any is on, see how
// that moves the head.
if(lines ^ stepper_mask_ && lines) {
// Convert from a representation of bits set to the centre of pull.
int direction = 0;
if(lines&1) direction += (((stepper_position_ - 0) + 4)&7) - 4;
if(lines&2) direction += (((stepper_position_ - 2) + 4)&7) - 4;
if(lines&4) direction += (((stepper_position_ - 4) + 4)&7) - 4;
if(lines&8) direction += (((stepper_position_ - 6) + 4)&7) - 4;
const int bits_set = (lines&1) + ((lines >> 1)&1) + ((lines >> 2)&1) + ((lines >> 3)&1);
direction /= bits_set;
// Compare to the stepper position to decide whether that pulls in the
// current cog notch, or grabs a later one.
step(Storage::Disk::HeadPosition(-direction, 4));
stepper_position_ = (stepper_position_ - direction + 8) & 7;
}
stepper_mask_ = lines;
}
bool DiskIIDrive::read() {
return !!(stepper_mask_ & 2) || get_is_read_only();
}