Package org.applecommander.device

Class TrackSectorNibbleDevice

java.lang.Object

org.applecommander.device.TrackSectorNibbleDevice

All Implemented Interfaces:

CapabilityProvider, TrackSectorDevice

public class TrackSectorNibbleDevice
extends Object
implements TrackSectorDevice

Nested Class Summary

Nested classes/interfaces inherited from interface org.applecommander.device.TrackSectorDevice

TrackSectorDevice.Geometry

Field Summary

Fields inherited from interface org.applecommander.device.TrackSectorDevice

SECTOR_SIZE

Constructor Summary

Constructors

Constructor	Description
TrackSectorNibbleDevice(NibbleTrackReaderWriter trackReaderWriter, DiskMarker diskMarker, NibbleDiskCodec dataCodec, int sectorsPerTrack)

Method Summary

Modifier and Type	Method	Description
boolean	can(Capability capability)
int	decodeOddEven(DataBuffer rawData, int offset)	Decode odd-even bytes as stored on disk.
void	encodeOddEven(DataBuffer data, int offset, int value)	Encode odd-even bytes to be stored on disk.
int	findSector(DataBuffer trackData, int track, int sector)
TrackSectorDevice.Geometry	getGeometry()
static int	locateField(int[] prolog, int[] epilog, DataBuffer trackData, DataBuffer fieldData, int startingOffset)	Locate a field on the track.
DataBuffer	readSector(int track, int sector)
void	writeSector(int track, int sector, DataBuffer data)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

TrackSectorNibbleDevice

public TrackSectorNibbleDevice(NibbleTrackReaderWriter trackReaderWriter,
 DiskMarker diskMarker,
 NibbleDiskCodec dataCodec,
 int sectorsPerTrack)

Method Details

can

public boolean can(Capability capability)

Specified by:

can in interface CapabilityProvider

getGeometry

public TrackSectorDevice.Geometry getGeometry()

Specified by:

getGeometry in interface TrackSectorDevice

decodeOddEven

public int decodeOddEven(DataBuffer rawData,
 int offset)

Decode odd-even bytes as stored on disk. The format will be in two bytes. They are stored as such:

     XX = 1d1d1d1d (odd data bits)
     YY = 1d1d1d1d (even data bits)
 

XX is then shifted by a bit and ANDed with YY to get the data byte. See page 3-12 in Beneath Apple DOS for more information.

encodeOddEven

public void encodeOddEven(DataBuffer data,
 int offset,
 int value)

Encode odd-even bytes to be stored on disk. See decodeOddEven for the format.

See Also:

• decodeOddEven(DataBuffer, int)

locateField

public static int locateField(int[] prolog,
 int[] epilog,
 DataBuffer trackData,
 DataBuffer fieldData,
 int startingOffset)

Locate a field on the track. These are identified by a 3 byte unique signature. Because of the way in which disk bytes are captured, we need to wrap around the track to ensure all sequences of bytes are accounted for. Note that we also check the epilog but allow it to be wiggly.

This method fills fieldData as well as returning the last position referenced in the track buffer.

findSector

public int findSector(DataBuffer trackData,
 int track,
 int sector)

readSector

public DataBuffer readSector(int track,
 int sector)

Specified by:

readSector in interface TrackSectorDevice

writeSector

public void writeSector(int track,
 int sector,
 DataBuffer data)

Specified by:

writeSector in interface TrackSectorDevice