Seagate Technology 10002475-003, Product Description Manual

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Chapter 7 Theory of Operations
Page 64 STT8000 ATAPI Minicartridge Drive
The 512-KB DRAM data buffer allows the drive to maintain streaming when
the host cannot provide data continuously at the tape streaming rate.
The write driver receives data from the write formatter and generates write
current, causing data to be written on tape by the tape head.
The read channel amplifies and conditions the signal from the tape head and
passes it back to the read formatter.
The head stepper and drive motor both receive current from the control logic to
control the stepping of the head from track to track and to move the tape
forward and back across the tape head.
Head Design
The recording/playback head is a state-of-the art, thin-film design—a thin-film
inductive write head paired with an advanced magneto-resistive read head.
This head design provides the drive with exceptional performance and
reliability. The material composition of the head also results in exceptional
wear characteristics, resulting in stable performance throughout the life of the
drive.
Flash EEPROM
Because the drive uses flash EEPROM (electronically erasable, programmable
read-only memory), the drive firmware can be easily upgraded when new
revisions of the firmware are released. The circuitry includes 128 KB of flash
EEPROM.
You can load new firmware by using a specially encoded firmware upgrade
cartridge.
Refer to chapter 4 for information about loading new firmware using a Seagate
firmware upgrade cartridge.
Sensors and Switches
A number of mechanical and optical sensors and switches are integrated in the
drive design. The Cartridge In switch detects when a cartridge is fully loaded
and positioned against the A-plane datum of the cartridge. The Unsafe switch
senses the position of the SAFE indicator on the cartridge and disables writing
of write-protected (SAFE) cartridges.
The Head-Position Sensor is an electro-optical assembly (LED and
phototransistor) to determine the approximate head position.
The drive has an electro-optical sensor assembly comprised of a solid-state light
source (LED) and a photosensor (phototransistor) that sense the beginning-of-
tape (BOT), end-of-tape (EOT), load point, and early warning holes of the
cartridge.