Hardware Data Compression; Active Terminator; Terminator Power - Seagate STD124000N Product Manual

Chapter 3

Hardware Data Compression

Active Terminator

Terminator Power

Page 26
Hardware data compression (HDC) is set by either using Switch S6 on the
switchbank or by using the jumper block.
The default setting is HDC enabled (no jumper on pins 9 and 10). Placing a jumper
on pins 9 and 10 overrides the switchbank setting and disables HDC.
As stated earlier, HDC can also be selected by the proper SCSI Mode Select
command issued by the host computer.
The Scorpion 24 drive provides a jumper-selectable active terminator feature as a
substitute for terminator resistor packs. Termination is required if the drive is the
only device on the SCSI bus or in the event that the drive is the last device on the
bus.
The active terminator option is disabled as the factory-default.
If you need to have an active terminator for the drive, place a jumper across pins 11
and 12.
The Scorpion 24 drive also provides jumper-selectable terminator power. You can
enable +5-volt terminator power if needed for terminators or other SCSI devices
through a jumper placement.
The factory-default for the Scorpion 24 drive is with terminator power disabled.
To enable terminator power, place the jumper shunt across pin 15 and 16 as shown
in Figure 12 on page 25.
Be sure the jumper is firmly in place.
!
Caution. If the jumper is installed, be careful not to short the TERMPWR
signal to ground.
The Scorpion 24 also contains a terminator power fuse to prevent damage to drive
components in case the terminator power is shorted. The terminator power fuse is
located beside the terminator power jumper.
In the event that the fuse has blown to prevent damage to the drive, please return
the drive to the nearest Seagate authorized repair facility for replacement.
Installation
DAT Drives