BizHawk/ExternalCoreProjects/Virtu/DiskIIDrive.cs

129 lines
3.9 KiB
C#

using System;
using System.IO;
using Jellyfish.Library;
using Jellyfish.Virtu.Services;
namespace Jellyfish.Virtu
{
public sealed class DiskIIDrive : MachineComponent
{
public DiskIIDrive() { }
public DiskIIDrive(Machine machine) :
base(machine)
{
DriveArmStepDelta[0] = new int[] { 0, 0, 1, 1, 0, 0, 1, 1, -1, -1, 0, 0, -1, -1, 0, 0 }; // phase 0
DriveArmStepDelta[1] = new int[] { 0, -1, 0, -1, 1, 0, 1, 0, 0, -1, 0, -1, 1, 0, 1, 0 }; // phase 1
DriveArmStepDelta[2] = new int[] { 0, 0, -1, -1, 0, 0, -1, -1, 1, 1, 0, 0, 1, 1, 0, 0 }; // phase 2
DriveArmStepDelta[3] = new int[] { 0, 1, 0, 1, -1, 0, -1, 0, 0, 1, 0, 1, -1, 0, -1, 0 }; // phase 3
}
public void InsertDisk(string name, byte[] data, bool isWriteProtected)
{
DebugService.WriteMessage("Inserting disk '{0}'", name);
FlushTrack();
_disk = Disk525.CreateDisk(name, data, isWriteProtected);
_trackLoaded = false;
}
public void RemoveDisk()
{
if (_disk != null)
{
DebugService.WriteMessage("Removing disk '{0}'", _disk.Name);
_trackLoaded = false;
_trackChanged = false;
_trackNumber = 0;
_trackOffset = 0;
_disk = null;
}
}
public void ApplyPhaseChange(int phaseState)
{
// step the drive head according to stepper magnet changes
int delta = DriveArmStepDelta[_trackNumber & 0x3][phaseState];
if (delta != 0)
{
int newTrackNumber = MathHelpers.Clamp(_trackNumber + delta, 0, TrackNumberMax);
if (newTrackNumber != _trackNumber)
{
FlushTrack();
_trackNumber = newTrackNumber;
_trackOffset = 0;
_trackLoaded = false;
}
}
}
public int Read()
{
if (LoadTrack())
{
int data = _trackData[_trackOffset++];
if (_trackOffset >= Disk525.TrackSize)
{
_trackOffset = 0;
}
Machine.DriveLight = true;
return data;
}
return 0x80;
// TODO: WTF was this
//return _random.Next(0x01, 0xFF);
}
public void Write(int data)
{
if (LoadTrack())
{
_trackChanged = true;
_trackData[_trackOffset++] = (byte)data;
if (_trackOffset >= Disk525.TrackSize)
{
_trackOffset = 0;
}
Machine.DriveLight = true;
}
}
private bool LoadTrack()
{
if (!_trackLoaded && (_disk != null))
{
_disk.ReadTrack(_trackNumber, 0, _trackData);
_trackLoaded = true;
}
return _trackLoaded;
}
public void FlushTrack()
{
if (_trackChanged)
{
_disk.WriteTrack(_trackNumber, 0, _trackData);
_trackChanged = false;
}
}
[Newtonsoft.Json.JsonIgnore]
public bool IsWriteProtected { get { return _disk.IsWriteProtected; } }
private const int TrackNumberMax = 0x44;
private const int PhaseCount = 4;
private int[][] DriveArmStepDelta = new int[PhaseCount][];
private bool _trackLoaded;
private bool _trackChanged;
private int _trackNumber;
private int _trackOffset;
private byte[] _trackData = new byte[Disk525.TrackSize];
private Disk525 _disk;
}
}