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			# DVDDAO Version 1.2.0+ #
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	Documentation of tests for DVD-RAM formatting with DVDDAO 1.2.0+
				by Ingo Steiner
			e-mail: ingo.steiner@gmx.net

	Revised: Nov. 2006 with DVDDAO 1.3.6


Conclusion of test results
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1. DVD-RAM can now be low-level formatted (takes 41 min. at 3x speed)
   using the option

	--format full

this maintains compatibility with existing applications like ADCreator 0.56.
Formatted capacity as obtained with readcd.exe from Cdrecord/2 package:

	f:\tools\cdr-2_0\readcd.exe dev=0,1,0 f=- | md5stdin.exe

Capacity: 2236704 Blocks = 4473408 kBytes = 4368 MBytes = 4580 prMB

This is how DVD-RAM disks are sold and the only choice to allow
'long formatting' with OS/2's UDF 2.14. UDF long formatting is required if
DVD-RAM was previously written on with non-UDF filesystems like CDFS.

This standard way of formatting provides already for 'spare sectors'
which the recorder uses to replace defect sectors during write.
According to literature these spare sectors are arranged like this:

	26 MB		of PSA (primary spare area)
	0 - 200 MB	of SSA (secondary spare area) can be
			expanded during writing if necessary.

There are two locations on the disk where spare sectors are located:

1.280 sectors	at the inner edge (beginning) of the DVD-RAM
6.112 sectors	at the outer edge (end) of the DVD-RAM

(it is unclear whether the count is in true sectors of 2.048 Bytes
or in units of 32 kB (= 1 ECC-sector, the minimum block size for writing)


2. DVD-RAM can also be low-level formatted (takes 40 min. at 3x speed)
	with option

	--format full --formatdescr max

This formats the whole disk without providing any? spare sector area
(or probably only the PSA?) and results in the full capacity of 4.7 GB:

Capacity: 2295072 Blocks = 4590144 kBytes = 4482 MBytes = 4700 prMB

Such a disk cannot be 'long formatted' with OS/2's UDF!
ISO-Images still can be written correctly on such a disk.

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Above two formatting options provide a real low-level long-format,
the recorder clears, verifies all formatted sectors, takes 40 min. at 3x.
The recorder can be inquired for all valid capacity descriptors applicable
for the inserted disk.

DVDDAO provides following command option for this inquiry:

	--formatdescr help

A typical output for a standard 3x DVD-RAM of 4.7 GB previously formatted with

	--format full --formatdescr max

is like this:

	1: Format type full (0x00). Capacity 2236704 sectors
	2: Format type full (0x00). Capacity 2295072 sectors
	3: Format type sparearea (0x01). Capacity 2285344
	4: Format type sparearea (0x01). Capacity 2275616
	5: Format type sparearea (0x01). Capacity 2265888
	6: Format type sparearea (0x01). Capacity 2256160
	7: Format type sparearea (0x01). Capacity 2246432
	8: Format type sparearea (0x01). Capacity 2236704
	9: Format type sparearea (0x01). Capacity 2226976
	10: Format type sparearea (0x01). Capacity 2217248


With a standard formatted disk by option '--format full' the output is:

	1: Format type full (0x00). Capacity 2236704 sectors
	2: Format type full (0x00). Capacity 2295072 sectors
	3: Format type sparearea (0x01). Capacity 2226976 sectors
	4: Format type sparearea (0x01). Capacity 2217248 sectors



The two formatting options described above under 1. and 2. are both
marked with the type full (0x00) and can be used for complete low-level
disk format.

The first one reported (Format type full (0x00). Capacity 2236704 sectors)
is automatically choosen when option '--format full' is used.

The second one (maximum, Format type full (0x00). Capacity 2295072 sectors) 
is automatically choosen when option '--format full --formatdescr max' is used.

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3. Secondary Spare Area (SSA) expanding

All other reported capacity descriptors with type sparearea (0x01)
can be used for expanding the secondary spare area (SSA) of a previously
'long formatted' DVD-RAM. This expansion only takes less than 1 minute.
Note that increasing the SSA, slightly reduces the available capacity for data.
DVDDAO provides following option to perform expansion of SSA:

	--formatdescr <num>

where <num> is the number reported by '--formatdescr help'.

Unfortunately OS/2's UDF 2.14 does not respect such expanded secondary
spare areas and refuses to execute 'format x: /fs:udf /l' command.
Other operarating systems or software however might work with such
disks.

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4. Verifying written data on DVD-RAM

As on a DVD-RAM sectors are 'hard-coded' and the disks usually come
formatted with UDF, any attempt to verify a DVD-RAM with the common
tools like 'readcd.exe' or 'IsoComp.exe' will report the checksum of the
whole disk, not repsecting the size of the copied data or image.

DVDDAO.exe has included the proper capabilities to manage also this
situation. On writing an image with DVDDAO you will get the necessary
information as output at the end like this:

	Info : Written 1193376 sectors, 2330 MB
	Info : Verifying written data...
	Info : Read data MD5: 9c8546aa38c96120ccd32c15a80822fa
	Info : Verification succeded

The important figure is the number of written sectors which you will have
to write down or save somewhere for future verifying. The verify at a
later time can be done in two ways with DVDDAO since version 1.2.1, when
writing to '/dev/null' was implemented.

	a) using the option '-S <size>'
	   here an example, where the drive is connected as slave:
	   dvddao.exe -d null: -S 1193376s scsi:0,2,0 (reads 1193376 sectors)

	b) using the possibility to specify a sector range for the DVD-drive:
	   here an example, where the drive is connected as master:
	   dvddao.exe -d null: scsi:0,1,0:0s-1193376s
	   this will start at sector 0 an read 1193376 sectors

I myself have created a program object for that case which asks you the
number of sectors to read (and calculate MD5) from a DVD-RAM like this:
	Program:	*
	Parameter:	/K dvddao.exe -d null: scsi:0,2,0:0s-[Sektorzahl]s
Of course it also works with any other DVD.

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WARNING:

If you intend to use DVD-RAM with UDF filesystem under OS/2
you MUST low-level format the DISK with DVDDAO's option

		'--format full'

Otherwise the disk cannot be correctly UDF-formatted !

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All tests were done with Recorder LG GSA-4040B Firmware A304 and
2-3x DVD-RAM with 4.7 GB nominal capacity from Panasonic. Disks came
low-level preformatted with 4368 MB and UDF 2.0 for video recording.
As all the described LOW-LEVEL FORMATTING is implemented and executed
in the Recorders FIRMWARE, options available may vary with manufacturer
and firmware revision. DVDDAO just queries and calls the available routines.
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