Specifications

The IEEE 1394b standard defines long-haul media using Cat 5 UTP and several kinds of optical fiber. The Power

Mac G5 computer is interoperable with such cables but cannot be directly connected to them. To use long-haul

cables, connect the computer to a 1394b hub that has the desired kind of long-haul connectors. If the hub has

a bilingual port, that port can be connected to any of the computer’s FireWire ports. If the hub has a beta-only

port, it can be connected only to the computer’s 9-pin port.

FireWire 400 Connector

The FireWire 400 ports 1 and 2 use the six-pin connectors shown in Figure 3-3 (page 34). The connector signals

and pin assignments are shown in Table 3-3 (page 34).

Figure 3-3 6-pin FireWire 400 connector

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Table 3-3 Signals on the 6-pin FireWire 400 connector

DescriptionSignal namePin

Power (approximately 25 V DC)Power1

Ground return for power and inner cable shieldGround2

Twisted-pair B MinusTPB–3

Twisted-pair B PlusTPB+4

Twisted-pair A MinusTPA–5

Twisted-pair A PlusTPA+6

Outer cable shield—Shell

Input and Output Devices

FireWire Ports