diff --git a/src/dos/cdrom_image.cpp b/src/dos/cdrom_image.cpp
index 2a31d224..bd4cb411 100644
--- a/src/dos/cdrom_image.cpp
+++ b/src/dos/cdrom_image.cpp
@@ -416,8 +416,9 @@ bool CDROM_Interface_Image::CanReadPVD(TrackFile *file, int sectorSize, bool mod
 	if (sectorSize == RAW_SECTOR_SIZE && !mode2) seek += 16;
 	if (mode2) seek += 24;
 	file->read(pvd, seek, COOKED_SECTOR_SIZE);
-	// pvd[0] = descriptor type, pvd[1..5] = standard identifier, pvd[6] = iso version
-	return (pvd[0] == 1 && !strncmp((char*)(&pvd[1]), "CD001", 5) && pvd[6] == 1);
+	// pvd[0] = descriptor type, pvd[1..5] = standard identifier, pvd[6] = iso version (+8 for High Sierra)
+	return ((pvd[0] == 1 && !strncmp((char*)(&pvd[1]), "CD001", 5) && pvd[6] == 1) ||
+			(pvd[8] == 1 && !strncmp((char*)(&pvd[9]), "CDROM", 5) && pvd[14] == 1));
 }
 
 #if defined(WIN32)
diff --git a/src/dos/dos_mscdex.cpp b/src/dos/dos_mscdex.cpp
index b0f1d187..ca406d71 100644
--- a/src/dos/dos_mscdex.cpp
+++ b/src/dos/dos_mscdex.cpp
@@ -117,7 +117,7 @@ public:
 	bool		GetAbstractName		(Bit16u drive, PhysPt data);
 	bool		GetDocumentationName(Bit16u drive, PhysPt data);
 	bool		GetDirectoryEntry	(Bit16u drive, bool copyFlag, PhysPt pathname, PhysPt buffer, Bit16u& error);
-	bool		ReadVTOC			(Bit16u drive, Bit16u volume, PhysPt data, Bit16u& error);
+	bool		ReadVTOC			(Bit16u drive, Bit16u volume, PhysPt data, Bit16u& offset, Bit16u& error);
 	bool		ReadSectors			(Bit16u drive, Bit32u sector, Bit16u num, PhysPt data);
 	bool		ReadSectors			(Bit8u subUnit, bool raw, Bit32u sector, Bit16u num, PhysPt data);
 	bool		ReadSectorsMSF		(Bit8u subUnit, bool raw, Bit32u sector, Bit16u num, PhysPt data);
@@ -577,7 +577,7 @@ Bit32u CMscdex::GetVolumeSize(Bit8u subUnit) {
 	return 0;
 }
 
-bool CMscdex::ReadVTOC(Bit16u drive, Bit16u volume, PhysPt data, Bit16u& error) { 
+bool CMscdex::ReadVTOC(Bit16u drive, Bit16u volume, PhysPt data, Bit16u& offset, Bit16u& error) {
 	Bit8u subunit = GetSubUnit(drive);
 /*	if (subunit>=numDrives) {
 		error=MSCDEX_ERROR_UNKNOWN_DRIVE;
@@ -589,11 +589,16 @@ bool CMscdex::ReadVTOC(Bit16u drive, Bit16u volume, PhysPt data, Bit16u& error)
 	}
 	char id[5];
 	MEM_BlockRead(data + 1, id, 5);
-	if (strncmp("CD001",id, 5)!=0) {
-		error = MSCDEX_ERROR_BAD_FORMAT;
-		return false;
+	if (strncmp("CD001", id, 5)==0) offset = 0;
+	else {
+		MEM_BlockRead(data + 9, id, 5);
+		if (strncmp("CDROM", id, 5)==0) offset = 8;
+		else {
+			error = MSCDEX_ERROR_BAD_FORMAT;
+			return false;
+		}
 	}
-	Bit8u type = mem_readb(data);
+	Bit8u type = mem_readb(data + offset);
 	error = (type == 1) ? 1 : (type == 0xFF) ? 0xFF : 0;
 	return true;
 }
@@ -602,12 +607,12 @@ bool CMscdex::GetVolumeName(Bit8u subUnit, char* data) {
 	if (subUnit>=numDrives) return false;
 	Bit16u drive = dinfo[subUnit].drive;
 
-	Bit16u error;
+	Bit16u offset = 0, error;
 	bool success = false;
 	PhysPt ptoc = GetTempBuffer();
-	success = ReadVTOC(drive,0x00,ptoc,error);
+	success = ReadVTOC(drive,0x00,ptoc,offset,error);
 	if (success) {
-		MEM_StrCopy(ptoc+40,data,31);
+		MEM_StrCopy(ptoc+offset+40,data,31);
 		data[31] = 0;
 		rtrim(data);
 	};
@@ -616,51 +621,51 @@ bool CMscdex::GetVolumeName(Bit8u subUnit, char* data) {
 }
 
 bool CMscdex::GetCopyrightName(Bit16u drive, PhysPt data) {	
-	Bit16u error;
+	Bit16u offset = 0, error;
 	bool success = false;
 	PhysPt ptoc = GetTempBuffer();
-	success = ReadVTOC(drive,0x00,ptoc,error);
+	success = ReadVTOC(drive,0x00,ptoc,offset,error);
 	if (success) {
 		Bitu len;
 		for (len=0;len<37;len++) {
-			Bit8u c=mem_readb(ptoc+702+len);
+			Bit8u c=mem_readb(ptoc+offset+702+len);
 			if (c==0 || c==0x20) break;
 		}
-		MEM_BlockCopy(data,ptoc+702,len);
+		MEM_BlockCopy(data,ptoc+offset+702,len);
 		mem_writeb(data+len,0);
 	};
 	return success; 
 }
 
 bool CMscdex::GetAbstractName(Bit16u drive, PhysPt data) { 
-	Bit16u error;
+	Bit16u offset = 0, error;
 	bool success = false;
 	PhysPt ptoc = GetTempBuffer();
-	success = ReadVTOC(drive,0x00,ptoc,error);
+	success = ReadVTOC(drive,0x00,ptoc,offset,error);
 	if (success) {
 		Bitu len;
 		for (len=0;len<37;len++) {
-			Bit8u c=mem_readb(ptoc+739+len);
+			Bit8u c=mem_readb(ptoc+offset+739+len);
 			if (c==0 || c==0x20) break;
 		}
-		MEM_BlockCopy(data,ptoc+739,len);
+		MEM_BlockCopy(data,ptoc+offset+739,len);
 		mem_writeb(data+len,0);
 	};
 	return success; 
 }
 
 bool CMscdex::GetDocumentationName(Bit16u drive, PhysPt data) { 
-	Bit16u error;
+	Bit16u offset = 0, error;
 	bool success = false;
 	PhysPt ptoc = GetTempBuffer();
-	success = ReadVTOC(drive,0x00,ptoc,error);
+	success = ReadVTOC(drive,0x00,ptoc,offset,error);
 	if (success) {
 		Bitu len;
 		for (len=0;len<37;len++) {
-			Bit8u c=mem_readb(ptoc+776+len);
+			Bit8u c=mem_readb(ptoc+offset+776+len);
 			if (c==0 || c==0x20) break;
 		}
-		MEM_BlockCopy(data,ptoc+776,len);
+		MEM_BlockCopy(data,ptoc+offset+776,len);
 		mem_writeb(data+len,0);
 	};
 	return success; 
@@ -718,13 +723,17 @@ bool CMscdex::GetDirectoryEntry(Bit16u drive, bool copyFlag, PhysPt pathname, Ph
 	// read vtoc
 	PhysPt defBuffer = GetDefaultBuffer();
 	if (!ReadSectors(GetSubUnit(drive),false,16,1,defBuffer)) return false;
-	// TODO: has to be iso 9960
 	MEM_StrCopy(defBuffer+1,volumeID,5); volumeID[5] = 0;
-	bool iso = (strcmp("CD001",volumeID)==0);
-	if (!iso) E_Exit("MSCDEX: GetDirEntry: Not an ISO 9960 CD.");
+	Bit16u offset;
+	if (strcmp("CD001",volumeID)==0) offset = 156;
+	else {
+		MEM_StrCopy(defBuffer+9,volumeID,5);
+		if (strcmp("CDROM",volumeID)==0) offset = 180;
+		else E_Exit("MSCDEX: GetDirEntry: Not an ISO 9660 or High Sierra CD.");
+	}
 	// get directory position
-	Bitu dirEntrySector	= mem_readd(defBuffer+156+2);
-	Bits dirSize		= mem_readd(defBuffer+156+10);
+	Bitu dirEntrySector	= mem_readd(defBuffer+offset+2);
+	Bits dirSize		= mem_readd(defBuffer+offset+10);
 	Bitu index;
 	while (dirSize>0) {
 		index = 0;
@@ -790,7 +799,7 @@ bool CMscdex::GetDirectoryEntry(Bit16u drive, bool copyFlag, PhysPt pathname, Ph
 					// Direct copy
 					MEM_BlockCopy(buffer,defBuffer+index,entryLength);
 				}
-				error = iso ? 1:0;
+				error = 1;
 				return true;
 			}
 			// change directory
@@ -1203,8 +1212,8 @@ static bool MSCDEX_Handler(void) {
 						};
 						return true;		
 		case 0x1505: {	// read vtoc 
-						Bit16u error = 0;
-						if (mscdex->ReadVTOC(reg_cx,reg_dx,data,error)) {
+						Bit16u offset = 0, error = 0;
+						if (mscdex->ReadVTOC(reg_cx,reg_dx,data,offset,error)) {
 //							reg_ax = error;	// return code
 							CALLBACK_SCF(false);
 						} else {
diff --git a/src/dos/drive_iso.cpp b/src/dos/drive_iso.cpp
index 8e4d96d0..6be44bd8 100644
--- a/src/dos/drive_iso.cpp
+++ b/src/dos/drive_iso.cpp
@@ -25,6 +25,9 @@
 #include "support.h"
 #include "drives.h"
 
+#define FLAGS1	((iso) ? de.fileFlags : de.timeZone)
+#define FLAGS2	((iso) ? de->fileFlags : de->timeZone)
+
 using namespace std;
 
 class isoFile : public DOS_File {
@@ -198,7 +201,7 @@ bool isoDrive::FileOpen(DOS_File **file, char *name, Bit32u flags) {
 	}
 	
 	isoDirEntry de;
-	bool success = lookup(&de, name) && !IS_DIR(de.fileFlags);
+	bool success = lookup(&de, name) && !IS_DIR(FLAGS1);
 
 	if (success) {
 		FileStat_Block file_stat;
@@ -234,7 +237,7 @@ bool isoDrive::MakeDir(char* /*dir*/) {
 
 bool isoDrive::TestDir(char *dir) {
 	isoDirEntry de;	
-	return (lookup(&de, dir) && IS_DIR(de.fileFlags));
+	return (lookup(&de, dir) && IS_DIR(FLAGS1));
 }
 
 bool isoDrive::FindFirst(char *dir, DOS_DTA &dta, bool fcb_findfirst) {
@@ -279,11 +282,11 @@ bool isoDrive::FindNext(DOS_DTA &dta) {
 	isoDirEntry de;
 	while (GetNextDirEntry(dirIterator, &de)) {
 		Bit8u findAttr = 0;
-		if (IS_DIR(de.fileFlags)) findAttr |= DOS_ATTR_DIRECTORY;
+		if (IS_DIR(FLAGS1)) findAttr |= DOS_ATTR_DIRECTORY;
 		else findAttr |= DOS_ATTR_ARCHIVE;
-		if (IS_HIDDEN(de.fileFlags)) findAttr |= DOS_ATTR_HIDDEN;
+		if (IS_HIDDEN(FLAGS1)) findAttr |= DOS_ATTR_HIDDEN;
 
-		if (!IS_ASSOC(de.fileFlags) && !(isRoot && de.ident[0]=='.') && WildFileCmp((char*)de.ident, pattern)
+		if (!IS_ASSOC(FLAGS1) && !(isRoot && de.ident[0]=='.') && WildFileCmp((char*)de.ident, pattern)
 			&& !(~attr & findAttr & (DOS_ATTR_DIRECTORY | DOS_ATTR_HIDDEN | DOS_ATTR_SYSTEM))) {
 			
 			/* file is okay, setup everything to be copied in DTA Block */
@@ -318,8 +321,8 @@ bool isoDrive::GetFileAttr(char *name, Bit16u *attr) {
 	bool success = lookup(&de, name);
 	if (success) {
 		*attr = DOS_ATTR_ARCHIVE | DOS_ATTR_READ_ONLY;
-		if (IS_HIDDEN(de.fileFlags)) *attr |= DOS_ATTR_HIDDEN;
-		if (IS_DIR(de.fileFlags)) *attr |= DOS_ATTR_DIRECTORY;
+		if (IS_HIDDEN(FLAGS1)) *attr |= DOS_ATTR_HIDDEN;
+		if (IS_DIR(FLAGS1)) *attr |= DOS_ATTR_DIRECTORY;
 	}
 	return success;
 }
@@ -334,7 +337,7 @@ bool isoDrive::AllocationInfo(Bit16u *bytes_sector, Bit8u *sectors_cluster, Bit1
 
 bool isoDrive::FileExists(const char *name) {
 	isoDirEntry de;
-	return (lookup(&de, name) && !IS_DIR(de.fileFlags));
+	return (lookup(&de, name) && !IS_DIR(FLAGS1));
 }
 
 bool isoDrive::FileStat(const char *name, FileStat_Block *const stat_block) {
@@ -346,7 +349,7 @@ bool isoDrive::FileStat(const char *name, FileStat_Block *const stat_block) {
 		stat_block->time = DOS_PackTime(de.timeHour, de.timeMin, de.timeSec);
 		stat_block->size = DATA_LENGTH(de);
 		stat_block->attr = DOS_ATTR_ARCHIVE | DOS_ATTR_READ_ONLY;
-		if (IS_DIR(de.fileFlags)) stat_block->attr |= DOS_ATTR_DIRECTORY;
+		if (IS_DIR(FLAGS1)) stat_block->attr |= DOS_ATTR_DIRECTORY;
 	}
 	
 	return success;
@@ -470,7 +473,7 @@ int isoDrive :: readDirEntry(isoDirEntry *de, Bit8u *data) {
 	
 	// modify file identifier for use with dosbox
 	if ((de->length < 33 + de->fileIdentLength)) return -1;
-	if (IS_DIR(de->fileFlags)) {
+	if (IS_DIR(FLAGS2)) {
 		if (de->fileIdentLength == 1 && de->ident[0] == 0) strcpy((char*)de->ident, ".");
 		else if (de->fileIdentLength == 1 && de->ident[0] == 1) strcpy((char*)de->ident, "..");
 		else {
@@ -499,11 +502,14 @@ int isoDrive :: readDirEntry(isoDirEntry *de, Bit8u *data) {
 }
 
 bool isoDrive :: loadImage() {
-	isoPVD pvd;
+	Bit8u pvd[COOKED_SECTOR_SIZE];
 	dataCD = false;
-	readSector((Bit8u*)(&pvd), ISO_FIRST_VD);
-	if (pvd.type != 1 || strncmp((char*)pvd.standardIdent, "CD001", 5) || pvd.version != 1) return false;
-	if (readDirEntry(&this->rootEntry, pvd.rootEntry)>0) {
+	readSector(pvd, ISO_FIRST_VD);
+	if (pvd[0] == 1 && !strncmp((char*)(&pvd[1]), "CD001", 5) && pvd[6] == 1) iso = true;
+	else if (pvd[8] == 1 && !strncmp((char*)(&pvd[9]), "CDROM", 5) && pvd[14] == 1) iso = false;
+	else return false;
+	Bit16u offset = iso ? 156 : 180;
+	if (readDirEntry(&this->rootEntry, &pvd[offset])>0) {
 		dataCD = true;
 		return true;
 	}
@@ -524,7 +530,7 @@ bool isoDrive :: lookup(isoDirEntry *de, const char *path) {
 
 		bool found = false;	
 		// current entry must be a directory, abort otherwise
-		if (IS_DIR(de->fileFlags)) {
+		if (IS_DIR(FLAGS2)) {
 			
 			// remove the trailing dot if present
 			size_t nameLength = strlen(name);
@@ -535,7 +541,7 @@ bool isoDrive :: lookup(isoDirEntry *de, const char *path) {
 			// look for the current path element
 			int dirIterator = GetDirIterator(de);
 			while (!found && GetNextDirEntry(dirIterator, de)) {
-				if (!IS_ASSOC(de->fileFlags) && (0 == strncasecmp((char*) de->ident, name, ISO_MAX_FILENAME_LENGTH))) {
+				if (!IS_ASSOC(FLAGS2) && (0 == strncasecmp((char*) de->ident, name, ISO_MAX_FILENAME_LENGTH))) {
 					found = true;
 				}
 			}
diff --git a/src/dos/drives.h b/src/dos/drives.h
index 0138163b..9d22da8c 100644
--- a/src/dos/drives.h
+++ b/src/dos/drives.h
@@ -363,6 +363,7 @@ private:
 		Bit8u data[ISO_FRAMESIZE];
 	} sectorHashEntries[ISO_MAX_HASH_TABLE_SIZE];
 
+	bool iso;
 	bool dataCD;
 	isoDirEntry rootEntry;
 	Bit8u mediaid;