From 558ae20c8002ae3ee3e33cc4b4ca6e6cf747c819 Mon Sep 17 00:00:00 2001
From: Robert Greene <robgreene@users.sourceforge.net>
Date: Thu, 12 Dec 2002 04:36:16 +0000
Subject: [PATCH] Added recognition for UniDOS 800K volumes (basically fixed 35
 track and 16 sector bias in code).

---
 .../applecommander/storage/Disk.java          | 28 +++++++++++++++----
 .../applecommander/storage/DosFormatDisk.java |  5 ++--
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/src/com/webcodepro/applecommander/storage/Disk.java b/src/com/webcodepro/applecommander/storage/Disk.java
index 0efff0e..061fd8a 100644
--- a/src/com/webcodepro/applecommander/storage/Disk.java
+++ b/src/com/webcodepro/applecommander/storage/Disk.java
@@ -350,7 +350,13 @@ public class Disk {
 	 * with.
 	 */
 	protected int getOffset(int track, int sector) throws IllegalArgumentException {
-		if ((track * 16 + sector) * SECTOR_SIZE > getPhysicalSize()) {
+		int length = diskImage.length;
+		if (length != APPLE_140KB_DISK && length != APPLE_800KB_DISK) {
+			throw new IllegalArgumentException("Unrecognized DOS format!");
+		}
+		int sectorsPerTrack = 16;
+		if (length == APPLE_800KB_DISK) sectorsPerTrack = 32;
+		if ((track * sectorsPerTrack + sector) * SECTOR_SIZE > getPhysicalSize()) {
 			throw new IllegalArgumentException(
 				"The track (" + track + ") and sector (" + sector 
 				+ ") do not match the disk image size.");
@@ -362,7 +368,7 @@ public class Disk {
 			return ((track * 8) + blockInterleave[sector]) * BLOCK_SIZE 
 				+ blockOffsets[sector] * SECTOR_SIZE;
 		} else if (isDosOrder()) {
-			return (track * 16 + sector) * SECTOR_SIZE;
+			return (track * sectorsPerTrack + sector) * SECTOR_SIZE;
 		} else {
 			throw new IllegalArgumentException(
 				"Unknown disk format.");
@@ -382,15 +388,25 @@ public class Disk {
 	
 	/**
 	 * Test the disk format to see if this is a DOS 3.3 formatted
-	 * disk.
+	 * disk.  This is a little nasty - since 800KB and 140KB images have
+	 * different characteristics.
 	 */
 	public boolean isDosFormat() {
 		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[0x02] == 15		// expect catalog to start on sector 15 (140KB disk only!)
+				||
+				vtoc[0x02] == 31		// expect catalog to start on sector 31 (800KB disk only!)
+				)
 			&& 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!)
+			&& ((
+				vtoc[0x34] == 35		// expect 35 tracks per disk (140KB disk only!)
+				&& vtoc[0x35] == 16		// expect 16 sectors per disk (140KB disk only!)
+				) || (
+				vtoc[0x34] == 50		// expect 50 tracks per disk (800KB disk only!)
+				&& vtoc[0x35] == 32		// expect 32 sectors per disk (800KB disk only!)
+				))
 			&& vtoc[0x36] == 0		// bytes per sector (low byte)
 			&& vtoc[0x37] == 1;		// bytes per sector (high byte)
 	}
diff --git a/src/com/webcodepro/applecommander/storage/DosFormatDisk.java b/src/com/webcodepro/applecommander/storage/DosFormatDisk.java
index 8d2a742..12d6656 100644
--- a/src/com/webcodepro/applecommander/storage/DosFormatDisk.java
+++ b/src/com/webcodepro/applecommander/storage/DosFormatDisk.java
@@ -464,10 +464,11 @@ public class DosFormatDisk extends FormattedDisk {
 	}
 	
 	/**
-	 * Validate track/sector range.
+	 * Validate track/sector range.  This just validates the
+	 * maximum values allowable for track and sector. 
 	 */
 	protected void checkRange(int track, int sector) {
-		if (track > 35 || sector > 32) {
+		if (track > 50 || sector > 32) {
 			throw new IllegalArgumentException(
 				"Invalid track (" + track + "), sector (" + sector
 				+ ") combination.");