Tape Drive List

The screen shot above shows two tape drives, one real and one emulated. By default DDPAB shows four tape drives, actual drives first, and emulated tape drives if necessary to fill the tape selection area up to four drives. Here we have moved the split divider so that only the first two drives are shown.

The first, actual, drive is a Compaq DLT8000 which we bought new for $189.99 from eBay. The firmware is at revision level 0259. The Quantum DLT Sage Utility application (Windows only) supports updating drive firmware. (We will have more on this later).

The ID 3 means that that the target ID selector on the drive has been set to position 3. Do not use 0 or 7, they are reserved for the host adapter and computer. You must make each drive's target ID unique if it is on the same adapter channel as another drive. To make it easier to distinguish drives, you should make all target ID's unique. The 3:0 below the target ID signifies that the card is in slot 3 and the drive is connected to channel 0.

Bringing Drives On-Line

In order for drives to appear in the tape drive area, they must be powered on when the computer is initially booted, or can be brought on-line later by rebooting or by running the ATTO Configuration Tool. They do not need to have a tape mounted at that time, and having a tape in the process of loading while booting may confuse the initialization process for some older drives with out-of-date firmware.

One Application at a Time

Tape drive support is actually a Parallel SCSI application layer that is loaded with the application, and is not part of the resident I/O. The OS X resident code supports ONLY ONE Application at a time! That mean the application must seize control of the Parallel SCSI support and prevent all other applications from even seeing the drives. If the application behaves the drives will be relinquished when it quits, and everything will be fine for the next application. If memory is trashed, it is likely that the computer will demand to be shut down in half a dozen languages. This can easily happen if you try to use the wrong ATTO driver. (See the Installation Requirements for further instructions).

So beware if running DVD Studio Pro, Retrospect, DVDAfterEdit, and DDPAB on the same machine. Be sure and quit the other applications if they have reserved the tape drives you want to use.

Tape Drive vs. Tape Cartridge

The left half of the tape info describes the tape drive. Below the description is the current tape drive status. Each drive operation is displayed there, but normally you only see the last operation or ongoing operation, such as "Writing" or "Tape rewound".

The third line in the tape drive section shows the progress bar and a cancel button when an operation is in progress.

To the right we have a box containing the current tape cartridge information for each tape drive. It contains the information below, but only if a tape is loaded:

Volume Name

The volume name is a name that is written at the beginning of the tape, just after the characters "VOL1" which identify the tape as a DDP tape. It is often the same or similar to the DISC name that is to appear on the finished disc. Some applications write only the "VOL1", and leave the volume name blank.

III or IV

This identifies the tape cartridge type that is loaded. DLT III tapes are much slower than DLT IV tapes when used in a DLT7000 or DLT8000. If the tape is protected, a red vertical bar shows to the left of the tape type icon.

Load/Unload Button

This button is used to load or unload a tape at any time.

DDP Description

This summarizes the DDP information that is read from the DDPID or DDVID file at the beginning of the tape. The last number is the number of sectors on the tape layer. A tape can only contain a single layer. The number of sectors is the same whether or not CSS is applied - the number doesn't change, only the size of the sectors, which are either 2048 bytes or 2054 bytes.

Source Box

The source box is used to select the source of the copy or verify function. In the screen shot above, the source selector has been popped up, and it shows the "Choose DDP Folder" menu item plus all of the available tape drives, in this case one actual drive and 3 tape emulators.

If a drive has already been chosen for the destination box, or is still busy performing a previous copy/verify operation, it will not be shown in this list.

Choosing the DDP Folder will put up a system file dialog that will allow selection only of valid DDP images, consisting of an enclosing folder (usually named with the DVD disc name) containing a Layer0 folder and a Layer1 folder if it is a DVD-9.

In the case of a DVD-9, it will select Layer0 in the layer popup, which you may then change to Layer1 to get the second layer.

Choosing the first (blank) entry in the popup will empty the source box.

You may drag a valid DDP folder from the desktop directly to the source box.

You may also drag a tape drive directly from the tape drive list to the source box.

Only tape drives containing a valid DDP image layer will be shown in the popup list.

Once a tape drive is selected, it will not be available as a destination.

Destination Box

This screen shot shows the popup for choosing an item for the destination box. Notice it is identical to the source popup, and that in the screen shot above the source box contains the second layer (Layer1) of a DDP Image on hard drive.

If you choose a destination DDP Image, you may create a new folder for that image, or choose an existing folder already containing one or more layer folders. This way you can extract DDP Image layers in either order from DVD-9 tapes.

If the folder already contains a folder for the same layer you are about to copy, your will be asked if you want to replace the contents of that folder.

All available tape drives may be selected as the destination, even if they do not yet have a tape mounted in them. Of course you must mount a non write-protected tape in order to proceed further.

You may drag a folder directly from the desktop to the destination box, or you may drag the folder to the tape list, which puts the folder in the source box and the tape drive in the destination box, all in one operation.

Log Information

The Log Information tracks each operation as it is performed, and thus makes it possible to review what you are doing to make sure you have things under control.

In the screen shot above, three tape emulators and one physical tape drive were mounted at startup. That means that the tape drive cartridge was mounted and ready, and the emulated tape drive disk files contained valid DDP images and were also mounted.

Then the user copied and verified the second layer of a DDP folder. Notice that it contained only 315,712 sectors, which at 2048 bytes per sector works out to about 616 MB. That's because we use an 8 cm. dual layer project for testing, to save time.

Notice that the DDP Image Layer contained only two files, the DDPID file which is the top-level file in all DDP's. (It is named DDVID.DAT in CMF, but contains the same data), and the MAIN.DAT file. This is because the CONTROL.DAT contains leadin information for the first layer, and is not needed on the second. Also, in CMF 1.0, the main file is usually named IMAGE.DAT.

Disc Description Protocol

Digital Linear Tape

Digital Linear Tapes (DLT's) have been the standard for submission of DDP Images for replication since day one. Although more and more replication facilities are now accepting images on hard drive, DVR-R data discs, or via FTP, there are still huge libraries of DLT tapes around the world, and DLT tapes have proven themselves to be a reliable storage medium.

DLT Drives

There are more modern DLT drives, but most replicators built their plants several years ago, and won't be able to read tapes from those drives. For replication, use DLT4000, DLT7000, or DLT8000 drives. DLT2000 and DLT2000 XT drives will also work, but only with DLT III cartridges. Do not buy an HVD (high-voltage differential) drive, since the vast majority of SCSI cards are low-voltage and connecting them to an HVD drive will fry them and burn down your office. Most drives are single-ended, but an LVD (log-voltage differential) will also work.

Cabling and Terminators

Proper cables and active terminators are a must. We use Computer Cablemakers in Sacramento. They sell worldwide, have every cable and adapter you could ever want, and are very reasonably priced.

http://www.computercablesource.com/

For UL5D, UL4S/D, or UL3S/D to DLT7000 or DLT8000 use this cable and terminator:
Scsi Cable - VHDCI-68 male to HD68 male - U320 LVD/SE/HVD - 003 foot
Part#: SCSU-320L-003 - $29

http://www.computercablesource.com/scsi-cable-vhdci-68-male-to-hd68-male...

SCSI Terminator - High density 68M Active with LED
Part#: SCST-5420
$15

http://www.computercablesource.com/scsi-terminator-high-density-68m-acti...

If you get an LVD drive, they also have an LVD terminator. And of course they have longer and shorter cables, and cables to go from drive to drive when putting more than one drive on a channel. If you have questions, call them.

Tape Drive Emulators

Tape Drive Emulators are pretend tape drives which write the same data to their disk files as would appear on the tape. The disk files are created in the user's application support folder for DDPAfterBurner, with the file names Tape101, Tape102, etc. A user preference specifies how many, if any, tape drive emulators are created when the application is loaded.

The tape files on disk are identical to the files as they would be written to tape, except for length words which are used to simplify the detection of file marks.

Until a tape drive emulator is used as the destination of a copy, it cannot be used as a source, since it is in effect an empty cartridge.

Preferences

There are three items in the preferences:

Emulated tape drives are useful for testing and for learning how the program works. Can be set to 0, up to a maximum of 9.

Set this flag on if you are having hardware or driver problems, and then send us the log file and system profile by selecting the Send Feedback option from the Help menu.

Filmarks are used to separate the tape headers, file data, and trailers. They can either be written in overlap mode, which keeps the tape moving at speed, or not, which is much slower. Some tape drives with older (bad) firmware are not capable of overlapping filemarks, and will not write them at all unless this option is disabled.

A better solution is to update the firmware, which at present can only be done on a PC, or on your Intel Mac in Windows mode.

Tape Tools

The Tape Tools window contains a tape selection popup, a function popup, a size or option popup, and an execute button. You select a tape drive, select a function, if that function has an option, select the option, and then hit the execute button to do the function.

The tape functions are:

Check Ready

Checks if the tape drive is ready, which means that there is a tape loaded and ready to read or write.

Load

This will load a tape if there is a tape in the drive and the handle is closed. If it is already loaded it has no effect. The loading process always takes at least a few moments, and can be quite lengthy if the drive has trouble recognizing the data on the tape, such as when it was written by a higher-density tape drive, or was just degaussed.

Unload

This will unload a tape if there is one loaded, and release the handle so that the tape can be removed. This takes a moment, but is much faster than loading a tape. If there is no tape loaded, it has no effect.

Rewind

If there is a tape loaded, it will make sure that the tape is rewound. It also serves as a Reset command, so any density or block length setting is lost. If the tape is already rewound, it has no other effect.

Read Buffer

This will read the number of bytes specified in the size popup into a local buffer, and display the first up to 80 bytes as ascii characters. The DDP format uses only a few tape block and tape record sizes, so the choices are limited.

Write Buffer

This writes the number of bytes specified in the size popup to the tape. The data written is the ascii character set in sequence, repeated. Again, the choices of record sizes to be written is limited.

Write Filemark

This writes a Filemark to the tape. Filemarks are used to indicate when there are no more records of the current block length and record length on the tape, and usually trigger a switch to reading or writing records of a different length or type.

Mode Sense

This command reads a relatively small number of tape drive parameters stored in its firmware, and does not require a tape to be loaded. These are mostly transient parameters, rather than drive preferences. Of particular interest are the tape cartridge type and whether or not it is write-protected.

Set Compression

This command sets or clears automatic tape compression. The built-in tape drive compression is geared towards text data, is useless for DVD data, and must always be turned off for DLT submissions.

Set Density

This command allows a higher-capacity tape drive to write tapes that can be read by lower-capacity drives. So far it doesn't work, but we haven't given up yet.

Set Block Length

This sets a block length so that the tape drive can transfer larger blocks of data, efficiently, as long as they are multiples of the given block length. Again, the block lengths are limited to those useful in the DDP format, except that 1K blocks may be specified.

Inquiry

The Inquiry command returns information about the drive. It can be executed even if the drive is not ready.

Text Mode Sense

This command reads a huge text string of all the drive preference settings. Each preference has a text name, a current value, a default value, a minimum value, and a maximum value. Some of these settings can prevent desired operation if they are set inappropriately. This command can be executed even if he drive is not ready.

Erase

Be careful! This command takes a very long time, and can't be stopped except by turning off the drive. The Tape Emulator version just erases the data in the disk file.

Purchasing Information

DDPAfterBurner is a new stand-alone utility for managing DDP Images on DLT (Digital Linear Tape). DDPAB is priced at $199 as a stand-alone utility, and at $99 (with coupon) for owners of HDAfterEdit. Download DDPAfterBurner.

DDPAB provides a new, modern interface to tape drive management, showing the DDP information for tapes as they are mounted, and treats each layer of a DDP as a separate entity. This eliminates having to start over with layer 0 if problems are encountered on subsequent layers, and can prevent mislabeling of tape cartridges. Writing and verifying can be specified in one step to avoid the need for operator intervention, and verification can also be done at any time.

DDPAB operates multiple drives in overlap without any throughput degradation, for both reading and writing. When used with the newer, much faster, DLT7000 and DLT8000 drives, it can greatly speed up the production process.

DDPAB 1.0 will offer a full AppleScript interface for automating tasks, both in stand-alone mode and in cooperation with HDAfterEdit. DDPAB does not convert DDP images to or from VIDEO_TS folders, that remains the province of HDAfterEdit or DVDAfterEdit.

DDPAfterBurner is being released as a non-expiring demo application that can be purchased and registered for full functionality from within the demo. For demo and testing purposes it implements up to nine disk-based tape drive emulators which write the same data to their disk files as would appear on the tape. Physical tape drives are fully functional in the demo version, except that copies are limited to layers of 1 GB or less.

Like HDAfterEdit, DDPAfterBurner can be updated to the latest version from within the program, via on-line notifications.

DDPAB provides built-in help from the Help menu, which can be stored locally or obtained on-line.

Installation Requirements

Hardware Requirements

Macintosh desktop computer with ATTO UL3S, UL3D, UL4S, UL4D, or UL5D SCSI adapter. Some older SCSI cards may work, at your own risk. The UL3 series are for PCI, UL4 for PCI-X, and UL5 for PCI Express slots. The 'S' means single channel, 'D' = dual channel.

or

Any Macintosh with ATTO iSCSI Ethernet adapter. This configuration has not been tested yet on Intel Macs, but is expected to work. The Ratoc Firewire to SCSI adapter has worked for some users with older DLT drives, but only for writing, not reading.

Software and Drivers

OS 10.4.10 or 10.4.11 (Tiger) or OS 10.5.1 (Leopard).

ATTO driver 4.20 for the UL5D (PCI-Express) or UL4S and UL4D (PCI-X).

https://www.attotech.com/software/driver34.html

ATTO driver 3.21 for the UL3S and UL3D (PCI).

https://www.attotech.com/software/disc/driver15.html

You must create an account at attotech.com to access their download page.

DLT Drives

DLT8000, DLT7000, DLT4000, DLT2000, or DLT2000 XT drive. Check Here for more informtion.