Theory Of Operations; Overview - Seagate STD124000N Product Manual

Theory of Operations

Overview

Product Manual
The Scorpion 24 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 drives are the result of:
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Combining the economies of scale from the audio electronics market for key
components, such as the cylinder, heads and audio LSIs, with a computer
grade drive (3.5-inch) using four direct drive motors, a no-mode change
mechanism and electronic tape path control for the demanding computer
storage environment.
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Implementing a four-head design to provide read-after-write (RAW) error
correction and to maximize the benefits of the helical scan recording method,
namely: (1) high-density recording (all tape space is used by dense, overlapping
tracks at alternating azimuth angles) and (2) high-speed searches.
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Using second-generation audio and custom LSIs for efficient circuit layout and
increased reliability with low power consumption. These LSIs are quad-flat-pack
(QFP) designs that use complementary metal-oxide semiconductor (CMOS)
technology.
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Implementing the DDS-3 format.
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Implementing hardware data compression in the drive using the SCSI/data-
compression chip.
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Using flash memory devices for easy firmware upgrades.
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Storing configuration information in the parameter block of flash memory.
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Enabling the user to access configuration information in the flash memory using
the SCSI MODE SENSE command and to program the flash memory using the
SCSI MODE SELECT command.
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Implementing custom C3 ECC coprocessor capabilities and other error-
correction techniques.
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Embedding a full-LSI SCSI controller with capability for SCSI-2 command sets
in single-ended SCSI DDS-DC models.
This chapter describes the Scorpion 24 DDS-3 drive in more detail and explains
implementation-specific information.
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