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Changing a jumper setting – IBM 704 User Manual

Page 308

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Changing Jumper and Switch Settings

Changing a Jumper Setting

A jumper covers pins on a pin block and might be positioned to the
left or to the right. The jumper setting depends on which pins are
covered.

To change a jumper setting:

1. Lift the jumper straight up off the pin block.
2. Slide the jumper down over the correct pins.

Note:

1. Always grip the narrow ends of the jumper when you

use a pair of fine needle-nosed pliers to remove or install
a jumper. Gripping the wide sides of the jumper can
damage contacts inside of the jumper, causing
intermittent problems.

Do not squeeze the pliers or other tool that you use to
remove a jumper, or you might bend or break the stake
pins on the board.

2. Jumper positions for system-board configuration jumpers

are described and illustrated in “Setting System-Board
Configuration Jumpers” on page 292.

Setting SCSI ID Jumpers

If you install additional SCSI devices in the upper-left front bay, set
their SCSI IDs so that they do not conflict with IDs used in the
hot-swap bays.

Jumpers on the front of the SCSI backplanes define the SCSI IDs for
hot-swap drives. See Table 14 on page 292 for the default SCSI IDs.

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PC Server 704 User's Handbook