. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DAT 72 and DDS-4 Tape Drives . . . . . . . . . . . .
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 exam
Introduction 3 In data-compression mode, the Seagate DAT 72 and DDS-4 drives typically double the storage capacity and transfer rate of the native u
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 install
Introduction 5 Figure 3. External Drive
6 DAT 72/DDS-4 Product Manual
Specifications 7 Specifications Overview This chapter includes technical specifications for the internal and external SCSI drives. This information
8 DAT 72/DDS-4 Product Manual 41.3 mm(1.63 in)101.6 mm(4.00 in)101.6 mm(4.00 in)94.0 mm(3.70 in)3.8 mm (0.15 in)13.0 mm (0.51 in)2 places5.0 mm
Specifications 9 Power Specifications The following table lists the power specifications for the internal DAT 72 and DDS-4 drives. Specification +12
10 DAT 72/DDS-4 Product Manual Drive Performance Specifications The following table lists the specifications for the DAT 72 drive. Specification Valu
Specifications 11 The following table lists the specifications for the DDS-4 drive. Specification Value Capacity (with 2:1 compression) 90 m MP 120
Copyright © 2003 by Certance LLC. All Rights Reserved.. Part Number: 50000712, June 2003 Certance and the Certance logo are tradema
12 DAT 72/DDS-4 Product Manual Environmental Requirements The following table lists the environmental specifications for DAT 72 and DDS-4 drives. The
Specifications 13 Mean Time Between Failures The mean time between failures (MTBF) is specified at 412,000 hours minimum. This specification includes
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 Re
Installation 15 Installation Introduction This chapter explains how to install the DAT 72 and DDS-4 drives. Some of the information relates to all m
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. Drive
Installation 17 SCSI ID=0SCSI ID=1SCSI ID=2SCSI ID=3SCSI ID=4SCSI ID=5SCSI ID=6SCSI ID=7SCSI ID=8SCSI ID=9SCSI ID=10SCSI ID=11SCSI ID=12SCSI ID=13SCS
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 jump
Installation 19 Media-Recognition System (Switch 3) The media-recognition system allows the drive to determine whether a given tape cartridge conform
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). F
Installation 21 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 mountin
FCC Notice This equipment generates and uses radio frequency energy and, if not installed and used properly—that is, in strict accordance with the m
22 DAT 72/DDS-4 Product Manual Ultra2 SCSI 68-pinhigh-density connectorpin 34pin 68pin 35pin 1 Figure 11. Interface Connector on an Internal Drive S
Installation 23 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. P
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 a
Installation 25 Connecting the SCSI Interface Cable The external drive provides two 68-pin, shielded connectors on the rear panel of the enclosure. E
26 DAT 72/DDS-4 Product Manual
Drive operation and maintenance 27 Drive Operation and Maintenance Loading a Cartridge Seagate DAT drives have a front-loading cartridge bay for eas
28 DAT 72/DDS-4 Product Manual CleanLED(green)MediaLED(green)EjectButtonDriveLED(amber) Figure 17. Location of the Eject Button and LEDs on i
Drive operation and maintenance 29 Write protectedWrite enabled Figure 18. Write-Protect Tab on a DDS Cartridge LED Codes As shown in Figure 19, th
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 cartridg
Drive operation and maintenance 31 • If the Drive LED is flashing rapidly, a hardware fault has occurred. If this fault occurs immediately after powe
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 dr
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
Drive operation and maintenance 33 • Place the drive in a position that provides stable temperatures. Do not place the drive near open windows, fans,
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 pro
Theory of operations 35 Theory of Operations Overview The Seagate DAT 72 and DDS-4 tape drive design integrates DAT technology (helical scan recordin
36 DAT 72/DDS-4 Product Manual factor. These design features are also important contributors to the overall reliability, durability and performance o
Theory of operations 37 Figure 20 illustrates a helix track and the four-head design, and shows the 102-degree wrap angle. 6˚ Drum inclination angle
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 mot
Theory of operations 39 Refer to Chapter 4 for information about loading new firmware using a Seagate firmware upgrade cartridge. Sensors A number of
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
Theory of operations 41 Slider Lock (2)Slider Lock (1)Datum HolesFile Protect Hole (Restorable)RecognitionHoles (1, 2, 3, 4)(4)(1)(2)(3)Lid Lock(L
iii Contents Contents Introduction 1 Overview...
42 DAT 72/DDS-4 Product Manual
Data compression 43 Data Compression Introduction Overview Typical data streams of text, graphics, software code or other forms of data contain repe
44 DAT 72/DDS-4 Product Manual Data Compression Considerations In an effective data-compression method, several factors are important: • The amount o
Data compression 45 Hardware Compression If data compression is used in software on the host computer rather than in the hardware of the drive, you c
46 DAT 72/DDS-4 Product Manual DCLZ Algorithm Within the computer industry, algorithms developed by Abraham Lempel and Jacob Ziv (enhanced later by T
Data compression 47 The following table illustrates this simplified operation. Input Byte Current String Match Build Entry Output Code Value R R Y
48 DAT 72/DDS-4 Product Manual • Dictionary codes, codewords 264 through 4,095: The dictionary codes refer to dictionary entries and represent multi
Data compression 49 The following steps describe a simplified version of the operation of the algorithm for decompressing data. 1. From a reset dicti
Publication Number: 50000712 Printed in USA
iv DAT 72/DDS Product Manual Unloading a Cartridge...27
v Contents Simplified Decompression Operation...48
vi DAT 72/DDS Product Manual Figures Figure 1. 3.5-Inch Internal Drive ......
Introduction 1 Introduction Overview The Seagate® DDS-4 (digital data storage) and DAT 72 (digital audio tape) drives are designed for computer envi
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