From b1a4c9d31d85982c1c841737aab4c9d1ab1efe61 Mon Sep 17 00:00:00 2001 From: Robert Greene Date: Tue, 10 Dec 2002 05:11:53 +0000 Subject: [PATCH] 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. --- .../applecommander/storage/Disk.java | 92 ++++++++++++++----- 1 file changed, 69 insertions(+), 23 deletions(-) diff --git a/src/com/webcodepro/applecommander/storage/Disk.java b/src/com/webcodepro/applecommander/storage/Disk.java index 31bea47..ca32c0a 100644 --- a/src/com/webcodepro/applecommander/storage/Disk.java +++ b/src/com/webcodepro/applecommander/storage/Disk.java @@ -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!)