Quantum DLT 2000 Handbook page 155

trol. In most cases, firmware interprets or translates commands from
you, from applications, or from communication controllers and
turns them into commands the machine or device can understand.
Firmware And Your DLTtape System
Every Quantum DLTtape system comes from the factory with
firmware loaded in EEPROMs on the controller board mounted at
the base of the drive. In the DLT 8000 drive, for example, there are
approximately 400,000 lines of code written, primarily, in the C
and C++ programming languages. That's a large program! Your
microwave oven, for instance, requires a mere 1,000-3,000 lines of
code in order to cook your frozen peas to perfection.
Firmware oversees the operation of the DLT 8000 drive's two
microprocessors and, through them, various other electronic drive
components. The personality of a DLTtape system is embodied in
its firmware. Nearly every aspect of operation is controlled
through firmware, including:
•
SCSI bus communications.
•
Data flow to and from the drive.
•
Adaptive caching.
•
Error detection/correction.
•
Event and "bugcheck" logs.
• Head servo control.
• Tape speed and tension control.
• Read/write control.
• Data formatting.
• Data compression.
• Library interface.
15.2 FIRMWARE