Adaptec AHA-1740A - Manual (Page 24)

Preparation
The configuration options for the AHA-1740A/1742A/1744 can be
selected from software. Therefore, jumpers do not need to be
checked before installing the AHA-1740A/1742A/1744 into the
EISA system.
One exception is the AHA-1742A, since it contains an on-board
floppy controller. The on-board floppy controller is shipped with a
jumper installed at J6, position 6, floppy enabled. If the floppy
controller on the AHA-1742A is not used, this jumper should be
removed. Only one floppy controller per EISA system can be
enabled.
The AHA-1740A/1742A/1744 has a jumper that can be changed.
This is the jumper block labeled J4, near the external connector.
This determines whether or not the AHA-1740A/1742A/1744 will
provide termination power to the SCSI bus. By default, the
jumper is installed and termination power is provided by the host
adapter. In general, the host adapter should always supply termi-
nator power. However, no more than five SCSI devices should be
configured to supply terminator power to a single SCSI bus.
adaptec AHA-1740A/1742A/1744
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