Table of Contents
Advertisement
ARCHIVE PYTHON DDS-DC OAT DRIVES---PRODUCT DESCRIPTION MANUAL
• • • MODE CHANGE
C:::
J
NO MODE CHANGE
Figure 8-4
Python State Diagram.
The custom automatic track finding (ATF) LSI combined with the four-head design implements the ANSI
DDS standard specifications and provides the precision required to perform seamless appends, the ability to
add information after a stop immediately adjacent to the last data written on the tape, with no significant loss
of tape storage capacity.
In Python internal models, an accessible switch bank lets you select certain operational options, such as a
default at power up of SCSI-1 or SCSI-2 interface, SCSI parity enable, DDS pass-through (uncompressed)
operation, and a power-on diagnostic self-test. A serial port is provided for access to firmware that provides
internal drive access. Also, a 6-pin header allows remote SCSI ID selection. Refer to Section 3.5.1 for
information about setting these operational switches.
Additionally, the internal models provide an accessible jumper at the rear of the drive that allows you to
enable terminator power if needed.
(The default for Python internal models is with terminator power
disabled. For external Python drives, the default is with terminator power enabled.)
NOTE: Also, a terminator power fuse
is
located at the rear of internal drives to provide
protection from component damage in case the SCSI cable
is
connected upside down
(with terminator power enabled).
The drive provides several sensors, both optical and mechanical, to conform to the ANSI Helical Scan Tape
Cassette specification; to effectively implement mode changes; and to insert and eject the cassette.
Two rectangular front panel light-emitting-diodes (LEDs) indicate drive busy status and tape cassette in
place status. When blinking, these LEDs also function as fault indicators. (Refer to Section 4.3 for a
summary of the function of these LEDs.) The 4352 external subsystem also provides a round, green LED on
the front panel to indicate power on.
The general information above is discussed in more detail in the following sections.
8-6
Advertisement
Table of Contents
