Quantum DAT 240 Loader Manual de usuario descargar pdf (Pagina 43)

Theory of operations

Overview

The Scorpion 240 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 signal-processing LSIs, with a computer grade drive (3.5-inch) using

four direct drive motors and electronic tape path control for the demanding

computer storage environment.

•

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.

•

Using second-generation signal-processing 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.

•

Implementing the DDS-4 format.

•

Using flash memory devices for easy firmware upgrades.

•

Storing configuration information in the onboard nonvolatile memory.

•

Enabling the user to access configuration information stored inside the drive

using the SCSI MODE SENSE command and to program the flash memory

using the SCSI MODE SELECT command.

•

Implementing custom ECC 1, 2, and 3 and other error-correction techniques.

•

Embedding a full-LSI SCSI controller with capability for SCSI-2 command sets in

single-ended and low-voltage differential (LVD) SCSI DDS-DC models.

•

Embedded 40 Mhz ARM CPU with cache

•

10-Mbyte SDRAM data buffer.

The rest of this chapter describes the Scorpion 240 DDS-4 drive in more detail and

provides implementation-specific information.

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Quantum DAT 240 Loader Manual de usuario Pagina 43