Seagate CD72LWH Product Manual page 6

iv
Theory of Operations
Data Compression
Unloading a Cartridge ................................................................................................27
Initializing a Blank Cartridge ......................................................................................28
DDS Cartridge Compatibility ......................................................................................28
Write-Protecting a Cartridge ......................................................................................28
LED Codes.................................................................................................................29
Clean LED ...........................................................................................................30
Media LED...........................................................................................................30
Drive LED ............................................................................................................30
LED Code Summary ...........................................................................................31
Cleaning the Tape Heads ..........................................................................................31
When to Clean the Tape Heads ..........................................................................31
How to Clean the Tape Heads ............................................................................32
Automatic Drive Spin-Down and Write.......................................................................32
Operating the Drive in High-Temperature or Humidity Conditions ............................32
Data Compression .....................................................................................................33
Loading Revised Firmware from Seagate Firmware Cartridges................................33
Flash Memory......................................................................................................33
Firmware Download Process via Tape ...............................................................33
Overview....................................................................................................................35
Drive Mechanism.................................................................................................35
Motors and Control Circuits .......................................................................................38
Timing Tracking Circuitry.....................................................................................38
Signal-Processing Electronics.............................................................................38
Flash Memory ............................................................................................................38
Sensors......................................................................................................................39
Read-After-Write ........................................................................................................39
Media Recognition System (MRS).............................................................................40
About the DDS Data Cartridge...................................................................................40
Introduction ................................................................................................................43
Overview .............................................................................................................43
Data Compression Considerations......................................................................44
Hardware Compression.......................................................................................45
Data Integrity .......................................................................................................45
DCLZ Algorithm .........................................................................................................46
Simplified Compression Operation......................................................................46
Dictionary ............................................................................................................47
DAT 72/DDS Product Manual
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