....................................... DAT 72 and DDS-4 Tape Drives ....................................... CD72LWH ....................................... CD72LWE ....................................... STD1401LW ....................................... STD2401LW ....................................... STD6401LW ....................................... Product Manual .......................................
Copyright © 2003 by Certance LLC. All Rights Reserved.. Part Number: 50000712, June 2003 Certance and the Certance logo are trademarks of Certance LLC. Seagate is a trademark of Seagate Technology LLC. Other product names are trademarks or registered trademarks of their respective owners. Certance reserves the right to change, without notice, product offerings or specifications. No part of this publication may be reproduced in any form without written permission from Certance LLC.
FCC Notice This equipment generates and uses radio frequency energy and, if not installed and used properly—that is, in strict accordance with the manufacturer’s instructions— may cause interference to radio communications or radio and television reception.
About This Manual This is the product manual for DAT 72 and DDS-4 internal and external tape drives. It describes how to use the DAT 72 and DDS-4 drives. Following are brief descriptions of the sections in this manual. Chapter 1, “Introduction” provides general specifications, features and an overview on DDS technology. Chapter 2, “Specifications” contains physical, performance, environmental, reliability, and power specifications.
iii Contents Contents Introduction 1 Overview...................................................................................................................... 1 DDS Format Standard Compatibility ..................................................................... 1 DAT 72 and DDS-4 Capacity and Transfer Rates ................................................ 2 Features ......................................................................................................................
iv DAT 72/DDS Product Manual Unloading a Cartridge ................................................................................................27 Initializing a Blank Cartridge ......................................................................................28 DDS Cartridge Compatibility ......................................................................................28 Write-Protecting a Cartridge ......................................................................................
v Contents Simplified Decompression Operation..................................................................
vi DAT 72/DDS Product Manual Figures Figure 1. 3.5-Inch Internal Drive ........................................................................................................................4 Figure 2. Internal Drive with Drive Rails for Mounting in a 5.25-inch Drive Bay ................................................4 Figure 3. External Drive .....................................................................................................................................5 Figure 4.
1 Introduction 1 Introduction Overview The Seagate® DDS-4 (digital data storage) and DAT 72 (digital audio tape) drives are designed for computer environments that require high-performance, high-capacity data storage. Based on a 3.5-inch mechanism, the internal and external models provide the following data storage capacities and native transfer rates: DDS-4 DAT 72 Data Storage Capacity: 20 Gbytes (40 Gbytes compressed) 36 Gbytes (72 Gbytes compressed) Native Transfer Rate: 2.
2 DAT 72/DDS-4 Product Manual The DAT 72 and DDS-4 drives support DDS data compression. Compression doubles a drive’s uncompressed capacity. For example, a 20 GB uncompressed drive will be 40 GB with compression.
3 Introduction In data-compression mode, the Seagate DAT 72 and DDS-4 drives typically double the storage capacity and transfer rate of the native uncompressed operation. Tape capacity and the sustained data-transfer rate are dependent upon the characteristics of the files being compressed, the application software used, and system parameters such as the speed of the host and the operating system.
4 DAT 72/DDS-4 Product Manual DAT 72 and DDS-4 Drive Models The DAT 72 and DDS-4 3.5-inch and 5.25-inch internal drives are tailored for easy installation in today’s computers, and the full-featured embedded SCSI controller facilitates easy integration into a variety of systems. DAT 72 and DDS-4 models include: • A 3.5-inch, half-height drive that mounts internally (see Figure 1) Figure 1. 3.5-Inch Internal Drive • A 5.25-inch, half-height drive that consists of a 3.5-inch drive with 5.
5 Introduction Figure 3.
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7 Specifications 2 Specifications Overview This chapter includes technical specifications for the internal and external SCSI drives.
8 DAT 72/DDS-4 Product Manual 41.3 mm (1.63 in) 101.6 mm (4.00 in) 13.0 mm (0.51 in) 2 places 3.8 mm (0.15 in) 5.0 mm (0.196 in) 2 places 94.0 mm (3.70 in) M3.0 x 4 deep min. (10 places) 90.0 mm (3.54 in) 2 places 70.0 mm (2.75 in) 60.0 mm (2.36 in) 2 places 31.0 mm (1.22 in) 21.0 mm (0.83 in) 2 places 41.2 mm (1.62 in) 146.0 mm (5.75 in) M3.0 x 4 deep min. (4 places) 6.0 mm (0.24 in) Side View 101.6 mm (4.00 in) Bottom View Note: Tolerance for all dimensions is 0.25mm (0.
9 Specifications Power Specifications The following table lists the power specifications for the internal DAT 72 and DDS-4 drives. Specification +12 VDC supply +5 VDC supply Voltage Tolerance Operational Current Standby Current Surge (peak) Ripple (peak-to-peak) + or – 10% operating 250 milliamps max 15 milliamps max 600 milliamps max ≤ 100 mV (peak to peak) + or – 7% operating 1.35 Amps max 1.2 Amps max 1.
10 DAT 72/DDS-4 Product Manual Drive Performance Specifications The following table lists the specifications for the DAT 72 drive. Specification Value Capacity 125 m MP++ 150 m MP+++ 170 m MP++++ Track density (DAT 72) 24.0 Gbytes 40.0 Gbytes 72.
11 Specifications The following table lists the specifications for the DDS-4 drive. Specification Capacity (with 2:1 compression) 90 m MP 120 m MP+ 125 m MP++ 150 m MP+++ Track density (DDS) Error recovery Value 4.0 Gbytes 8.0 Gbytes 24.0 Gbytes 40.0 Gbytes 147.
12 DAT 72/DDS-4 Product Manual Environmental Requirements The following table lists the environmental specifications for DAT 72 and DDS-4 drives. The internal drive should meet these standards if mounted either vertically (on its side) or horizontally (right side up).
13 Specifications Mean Time Between Failures The mean time between failures (MTBF) is specified at 412,000 hours minimum. This specification includes all power-on and operational time but excludes maintenance periods. Operational time is assumed to be 20 percent of the power-on time. Operational time is the time the tape is loaded on the cylinder (tape moving and/or cylinder rotating). Note: The MTBF rating does not represent any particular drive, but is derived from a large database of test samples.
14 DAT 72/DDS-4 Product Manual Regulatory Compliance The DAT 72 and DDS-4 drives comply with the regulations listed in the following table. Agency Regulation CSA C22.2, No. 950-M89 TUV-RHEINLAND EN 60 950 UL 1950 FCC Class A and Class B1 CE CE compliance 1. Required compliance for external model; verification on file for internal models.
15 Installation 3 Installation Introduction This chapter explains how to install the DAT 72 and DDS-4 drives. Some of the information relates to all models; other information is specifically aimed at either the internal or external models. The following paragraphs briefly outline the organization of this chapter. • Unpacking and Inspection: contains general information that you should read before installation. • Installing an Internal Drive: describes how to install a 3.5-inch internal drive and a 3.
16 DAT 72/DDS-4 Product Manual Note: Internal drives come in two mounting configurations for 3.5-inch and 5.25-inch drive bays, respectively. Drives configured for 5.25-inch bays are identical to those used for 3.5-inch bays, except for the addition of drive mounting brackets on each side of the drive and a different front bezel. Installation procedures are the same for both drive configurations.
17 Installation Default jumper settings shown (SCSI ID 6, parity checking enabled, and termination power disabled) Pins: 1-2 3-4 5-6 7-8 9-10 11-12 Function: SCSI ID bit 0 SCSI ID bit 1 SCSI ID bit 2 SCSI ID bit 3 Parity checking Termination Power SCSI ID=0 SCSI ID=8 SCSI ID=1 SCSI ID=9 SCSI ID=2 SCSI ID=10 SCSI ID=3 SCSI ID=11 SCSI ID=4 SCSI ID=12 SCSI ID=5 SCSI ID=13 SCSI ID=6 SCSI ID=14 SCSI ID=7 SCSI ID=15 Parity enable Term. power Figure 6.
18 DAT 72/DDS-4 Product Manual Terminator Power (Pins 11 and 12) Internal DAT 72 and DDS-4 drives are shipped with terminator power disabled (no jumper across pins 11 and 12, as shown in Figure 6). You can enable terminator power, if necessary, by placing a jumper across pins 11 and 12. Note 1: If the termination power jumper is installed, be careful not to short the TERMPWR signal to ground (for example, by attaching the SCSI cable upside down).
19 Installation Media-Recognition System (Switch 3) The media-recognition system allows the drive to determine whether a given tape cartridge conforms to the DDS tape standard. Use of non-DDS media may appear to give satisfactory results, but the inferior specifications of such media can cause dataintegrity problems. Switch 3 is reserved on DAT72 drives. On DDS-4 drives, switch 3 enables or disables the media-recognition system (MRS).
20 DAT 72/DDS-4 Product Manual Mounting an Internal Drive You can install your Seagate internal DDS drive horizontally or vertically (on its side). Figure 8 shows a 3.5-inch drive being installed in a typical system using side mounting screws. Mounting the Drive in a 3.5-Inch Drive Bay Mount the drive in a 3.5-inch drive bay and secure it using two M3.0 metric screws on each side of the drive. Do not use nonmetric screws or screws longer than 4 mm or you might damage the drive.
21 Installation Mounting the Drive in a 5.25-Inch Drive Bay If you are mounting the drive in a 5.25-inch drive bay, you must use a drive with mounting brackets attached. As shown in Figure 10, the 5.25-inch drive brackets have four screw holes on the bottom and six on each side. 41.3 mm (1.63 in) 31.5 mm (1.24 in) 21.8 mm (0.86 in) 146 mm (5.75 in) 9.9 mm (0.39 in) 16-M3 174.6 mm (6.87 in) 79.4 mm (3.13 in) 47.6 mm (1.87 in) 41.2 mm (1.62 in) 139.7 mm (5.50 in) 149.1 mm (5.
22 DAT 72/DDS-4 Product Manual pin 34 Ultra2 SCSI 68-pin high-density connector pin 1 pin 35 pin 68 Figure 11. Interface Connector on an Internal Drive SCSI Termination The internal DAT 72 and DDS-4 drives do not provide SCSI termination. For this reason, they should not be the last device on a SCSI chain. Two termination examples are shown in Figure 12.
23 Installation The recommended 4-pin power connector for the internal drive is an AMP 1-48024-0 housing with AMP 60617-1 pins or their equivalent. Power connector pin 4 +5V pin 3: GND (+5V return) pin 1 12V pin 2: GND (+12V return) Figure 13.
24 DAT 72/DDS-4 Product Manual Installing an External Drive The external drive is a compact external SCSI device that connects to the host computer as a turnkey subsystem. Installing the external drive involves three simple steps: 1. Configuring the drive 2. Connecting the SCSI interface cable 3.
25 Installation Connecting the SCSI Interface Cable The external drive provides two 68-pin, shielded connectors on the rear panel of the enclosure. Either connector can be used as a SCSI IN or SCSI OUT connection (you can use either connector to attach the drive to the host computer or to another SCSI device). Turn off your computer and all SCSI devices. Then attach a SCSI cable from the host adapter or from another (unterminated) SCSI device to the external drive.
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27 Drive operation and maintenance Drive Operation and Maintenance 4 Loading a Cartridge Seagate DAT drives have a front-loading cartridge bay for easy operation. The drivebay door opens automatically when a cartridge is inserted. Figure 16 shows a cartridge being inserted into a 3.5-inch internal drive. After you insert the cartridge, there is a brief delay while the drive identifies the cartridge type and state and moves the tape to the data area. Figure 16.
28 DAT 72/DDS-4 Product Manual Clean LED (green) Media LED (green) Drive LED (amber) Eject Button Figure 17. Location of the Eject Button and LEDs on internal Drives (external drive is similar) Initializing a Blank Cartridge When you insert a blank cartridge into the drive for the first time, the drive takes about 10 to 12 seconds to determine that the tape is blank. The drive automatically initializes the tape as soon as it receives a Write command from the host computer.
29 Drive operation and maintenance Write protected Write enabled Figure 18. Write-Protect Tab on a DDS Cartridge LED Codes As shown in Figure 19, the front panel of the DDS drive contains three LEDs that provide information about both normal and error conditions. The external drive also includes a green power-on LED on the front panel. Clean LED (green) Media LED (green) Drive LED (amber) Figure 19.
30 DAT 72/DDS-4 Product Manual Clean LED If the Clean LED is ON continuously, the drive requires cleaning. Use only an approved DDS cleaning cartridge. Following is a guideline for cleaning intervals based upon drive type: • DDS-4 DDS2, DDS3, or DDS4 media has been operating in the drive for at least 50 hours. • DAT 72 DDS3, DDS4, or DAT 72 media has been operating in the drive for at least 50 hours.
31 Drive operation and maintenance • If the Drive LED is flashing rapidly, a hardware fault has occurred. If this fault occurs immediately after powering on the drive, then the Power-On Self-Test switch is enabled and a Power-On Self-Test has failed. If the front panel LEDs flash together, contact the Seagate Technical Support department for information. If the Drive LED is flashing rapidly during drive operation, attempt to remove the tape by pressing the eject button.
32 DAT 72/DDS-4 Product Manual Note: If cleaning the head does not correct a flashing LED condition, try using a new data cartridge. How to Clean the Tape Heads To clean the tape heads on your drive, use only a Seagate-qualified DDS cleaning cartridge. Seagate offers a cleaning cartridge, Model STDMCL or CDMCL, available from http://shop.certance.com. Do not use an audio DAT cleaning cartridge. The drive cannot recognize it.
Drive operation and maintenance 33 • Place the drive in a position that provides stable temperatures. Do not place the drive near open windows, fans, heaters or doors. • Do not read from or write to cartridges when a temperature change of 10°C per hour is occurring. Data Compression Default operation for the DAT 72 and DDS-4 drives is to have data compression enabled—the drive automatically compresses all data written to tape and decompresses all compressed data read from tape.
34 DAT 72/DDS-4 Product Manual 2. Make sure that no applications are running that may try to communicate to the drive during the firmware upgrade process. Close any such applications before inserting the firmware upgrade cartridge. 3. Insert the firmware upgrade cartridge. ! Caution. Once the firmware upgrade cartridge is inserted into the drive, it is important that no power interruption occurs while the firmware is loading. Do not power off the drive.
35 Theory of operations Theory of Operations 5 Overview The Seagate DAT 72 and DDS-4 tape drive design integrates DAT technology (helical scan recording method) into a true computer-grade data-storage peripheral with industry-standard data-compression capability. These drive designs are the result of: • Combining the economies of scale for key components, such as the cylinder, heads, and audio Application Specific Integrated Circuits (ASICs), with a computer grade drive (3.
36 DAT 72/DDS-4 Product Manual factor. These design features are also important contributors to the overall reliability, durability and performance of the drive. The mechanism is designed for minimum tape wear and prevention of damage to the tape. The modes or operational states, such as stop, rewind and play, reduce mechanism and tape wear. Fewer mechanical mode changes result in less wear on key drive components.
37 Theory of operations Figure 20 illustrates a helix track and the four-head design, and shows the 102-degree wrap angle. 6˚ Drum inclination angle Direction of drum rotation: Read Head B Write Head B Write Head A Read Head A Tape Direction Tape Drum 102˚ Angle of tape wrap Track of one recording head across tape surface Figure 20. Four-Head Cylinder Design The recorded tracks are written diagonally across the tape from bottom to top by each write head.
38 DAT 72/DDS-4 Product Manual Motors and Control Circuits The drive uses four direct-drive, brushless motors—the capstan, cylinder and two reel motors. Using these small, direct-drive motors provides maximum reliability. The cylinder motor rotates the cylinder. The capstan motor moves the tape. The mode motor loads and ejects the cartridge. The two reel motors turn the tape reels. The cylinder, capstan and reel servos are controlled by custom ASICs and the motor-control firmware.
39 Theory of operations Refer to Chapter 4 for information about loading new firmware using a Seagate firmware upgrade cartridge. Sensors A number of mechanical and optical sensors are integrated in the drive design. The cartridge in and cartridge loading sensors are mechanical sensors that determine the position of the loading mechanism. The other mechanical sensors report specific information based on detecting the open or closed state of four recognition holes in the DAT cartridge.
40 DAT 72/DDS-4 Product Manual Media Recognition System (MRS) The tape drive includes support for the media recognition system (MRS), which is unique to DDS products. The MRS refers to a series of alternate opaque and clear stripes at the beginning of each tape. These stripes are used to classify the media as data- or computer-grade, rather than audio-grade, media.
41 Theory of operations File Protect Hole (Restorable) Datum Holes (4) Recognition Holes (1, 2, 3, 4) Slider Lock (1) (3) (2) (1) Lid Lock (Locked by Slider) Slider Lock (2) Figure 22. DDS Drive Cartridge Design Features Qualified DDS cartridges are designed with specific write-protect, lid and other features for information interchange and are tested to comply with the ANSI DDS specifications. The DAT 72 and DDS-4 drives also recognize all MRS cartridges when MRS is enabled.
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43 Data compression Data Compression 6 Introduction Overview Typical data streams of text, graphics, software code or other forms of data contain repeated information of some sort, whether it is at the text level where you can readily recognize regular repetitions of a single word or at the binary level where the repetitions are in bits or bytes. Although most data is unique and random, the binary level data exhibits patterns of various sizes that repeat with varying degrees of regularity.
44 DAT 72/DDS-4 Product Manual Data Compression Considerations In an effective data-compression method, several factors are important: • The amount of compression (measured by the compression ratio, which is a ratio that compares the amount of uncompressed data to the amount of compressed data and is obtained by dividing the size of the uncompressed data by the size of the compressed data) • The speed with which data is compressed and decompressed in relation to the host transfer rate • The types of
45 Data compression Hardware Compression If data compression is used in software on the host computer rather than in the hardware of the drive, you can slow down the transfer rate of the host because it must perform compression computations in addition to its regular computations. Also, any other host that wants to retrieve (decompress) the data must have the same software.
46 DAT 72/DDS-4 Product Manual DCLZ Algorithm Within the computer industry, algorithms developed by Abraham Lempel and Jacob Ziv (enhanced later by Terry Welch) are popular, versatile and powerful compression methods. These LZ algorithms are basically of two types—LZ1, a sliding window method, and LZ2/LZW, a hashed directory method. LZ2 and LZW (Lempel-Ziv-Welch) are algorithms based on the hashed dictionary method; these algorithms offer an acceptable compromise between speed and compression ratio.
47 Data compression The following table illustrates this simplified operation. Input Byte R I — N — T — I — N T — I N — Current String R RI I IN N NT T TI I IN INT T TI TIN N Match Y N Y N Y N Y N Y Y N Y Y N Y Build Entry — RI — IN — NT — TI — — INT — — TIN — Output Code Value — (R) — (I) — (N) — (T) — — (IN) — — (TI) — Dictionary The dictionary is built and contained logically in external RAM and is not output as a distinct item.
48 DAT 72/DDS-4 Product Manual • Dictionary codes, codewords 264 through 4,095: The dictionary codes refer to dictionary entries and represent multiple bytes (a string of characters) in the input data stream. These codes are built as the input stream is processed. These codes are pointers to other locations and eventually end by pointing to one of the byte values 0 through 255. A linked chain is created that builds up a string of characters.
49 Data compression The following steps describe a simplified version of the operation of the algorithm for decompressing data. 1. From a reset dictionary point, (which contains only control codes and encoded bytes) codewords are fetched from the input stream and looked up in the dictionary. 2. New dictionary codes are built by combining the previously received codewords. (The dictionary created during compression is recreated, guaranteeing that any codeword received is contained in the dictionary.
Publication Number: 50000712 Printed in USA
