Master/Slave Configuration - Seagate ST3655 Series Product Manual

ST3655 Family AT Drives Product Manual, Rev. A

2.4.3 Master/slave configuration

Your drive is shipped with a jumper installed in a spare location on pins 1
and 3 of the master/slave jumper block. If you are installing only one
drive, you can leave the jumper installed on pins 1 and 3, or you can
remove all jumpers from the jumper block.
You can install up to two drives in a standard AT system. If you are
installing two drives in your system, configure one drive as the master
and the other as the slave according to the following guidelines:
• To configure the drive as a master with a slave present, install a jumper
on pins 3 and 4 only of the master/slave jumper block of the master
drive.
Note. If both the master and the slave are ST3655 family drives, you
do not need to install a jumper on pins 3 and 4. This is because
the master can detect the presence of the slave using the
DASP– signal on the AT interface cable. If the drives in your
application do not implement the DASP– signal, install the
jumper on pins 3 and 4 of the master/slave jumper block on the
master drive only.
• To configure the drive as a slave, install a jumper on pins 1 and 2 only
of the master/slave jumper block on the slave drive.
With the aid of a special interface ribbon cable, the cable select option
allows you to determine the master and slave according to where the
drives are plugged in the cable. Cable select is described in more detail
in Section 2.5.
Note. Early ST3655 family drives do not support the cable select option.
To use cable select on an ST3550A, your circuit board part number
must be 260058-109 or 260100- xxx . To use cable select on an
ST3390A or an ST3655A, your circuit board part number must be
260124- xxx .
17