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AppleCommander
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Added write block and lessened the DOS 3.3 recognition. For some 

reason, some DOS 3.3 images do not set the VTOC byte 0x03 to be
3 - this is the DOS release number which created the disk. The images
I have just have a zero (0) in this position.
This commit is contained in:
Robert Greene 2002-12-10 05:11:53 +00:00
parent 24ebe07191
commit b1a4c9d31d
1 changed files with 69 additions and 23 deletions
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92
src/com/webcodepro/applecommander/storage/Disk.java
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@ -249,32 +249,79 @@ public class Disk {
}
/**
* Get the block from the disk image.
* Read the block from the disk image.
*/
public byte[] readBlock(int block) {
byte[] data = new byte[BLOCK_SIZE];
System.arraycopy(readBytes(getOffset1(block), SECTOR_SIZE),
0, data, 0, SECTOR_SIZE);
System.arraycopy(readBytes(getOffset2(block), SECTOR_SIZE),
0, data, SECTOR_SIZE, SECTOR_SIZE);
return data;
}
/**
* Write the block to the disk image.
*/
public void writeBlock(int block, byte[] data) {
byte[] sector = new byte[SECTOR_SIZE];
System.arraycopy(data, 0, sector, 0, SECTOR_SIZE);
writeBytes(getOffset1(block), sector);
System.arraycopy(data, SECTOR_SIZE, sector, 0, SECTOR_SIZE);
writeBytes(getOffset2(block), sector);
}
/**
* Compute the block offset into the disk image.
* Note that for ProDOS blocks the offset is broken into two
* pieces - depending of the format the image is in, they may
* or may not be adjacent within the disk image itself.
* This takes into account what type of format is being dealt
* with.
*/
protected int getOffset1(int block) throws IllegalArgumentException {
if (block * BLOCK_SIZE > getPhysicalSize()) {
return null;
throw new IllegalArgumentException("The block (" + block
+ ") does match the disk image size.");
} else if (isProdosOrder()) {
return block*BLOCK_SIZE;
} else if (isDosOrder()) {
int[] sectorMapping1 = { 0, 13, 11, 9, 7, 5, 3, 1 };
int track = block / 8;
int sectorOffset = block % 8;
int sector1 = sectorMapping1[sectorOffset];
int physicalLocation1 = (track * 16 + sector1) * SECTOR_SIZE;
return physicalLocation1;
} else {
if (isProdosOrder()) {
return readBytes(block*BLOCK_SIZE, BLOCK_SIZE);
} else if (isDosOrder()) {
int[] sectorMapping1 = { 0, 13, 11, 9, 7, 5, 3, 1 };
int[] sectorMapping2 = { 14, 12, 10, 8, 6, 4, 2, 15 };
int track = block / 8;
int sectorOffset = block % 8;
int sector1 = sectorMapping1[sectorOffset];
int sector2 = sectorMapping2[sectorOffset];
int physicalLocation1 = (track * 16 + sector1) * SECTOR_SIZE;
int physicalLocation2 = (track * 16 + sector2) * SECTOR_SIZE;
byte[] data = new byte[BLOCK_SIZE];
System.arraycopy(readBytes(physicalLocation1, SECTOR_SIZE),
0, data, 0, SECTOR_SIZE);
System.arraycopy(readBytes(physicalLocation2, SECTOR_SIZE),
0, data, SECTOR_SIZE, SECTOR_SIZE);
return data;
} else {
return null;
}
throw new IllegalArgumentException(
"Unknown disk format.");
}
}
/**
* Compute the block offset into the disk image.
* Note that for ProDOS blocks the offset is broken into two
* pieces - depending of the format the image is in, they may
* or may not be adjacent within the disk image itself.
* This takes into account what type of format is being dealt
* with.
*/
protected int getOffset2(int block) throws IllegalArgumentException {
if (block * BLOCK_SIZE > getPhysicalSize()) {
throw new IllegalArgumentException("The block (" + block
+ ") does match the disk image size.");
} else if (isProdosOrder()) {
return block*BLOCK_SIZE + SECTOR_SIZE;
} else if (isDosOrder()) {
int[] sectorMapping2 = { 14, 12, 10, 8, 6, 4, 2, 15 };
int track = block / 8;
int sectorOffset = block % 8;
int sector2 = sectorMapping2[sectorOffset];
int physicalLocation2 = (track * 16 + sector2) * SECTOR_SIZE;
return physicalLocation2;
} else {
throw new IllegalArgumentException(
"Unknown disk format.");
}
}
@ -337,7 +384,6 @@ public class Disk {
byte[] vtoc = readSector(17, 0);
return vtoc[0x01] == 17 // expect catalog to start on track 17
&& vtoc[0x02] == 15 // expect catalog to start on sector 15
&& vtoc[0x03] == 3 // expect DOS release number of 3
&& vtoc[0x27] == 122 // expect 122 tract/sector pairs per sector
&& vtoc[0x34] == 35 // expect 35 tracks per disk (140KB disk only!)
&& vtoc[0x35] == 16 // expect 16 sectors per disk (140KB disk only!)