Hardware Reference
In-Depth Information
• Support for CAT5 cable, even though it uses pairs on pins 1/2 and 7/8 only for greater
reliability. It also doesn't require crossover cables.
TheinitialimplementationsofIEEE1394buseanewnine-wireinterfacewithtwopairsof
signalingwires.However,toenablea1394bporttoconnectto1394a-compatibledevices,
two versions of the 1394b port are used:
• Beta
• Bilingual
Beta connectors support only 1394b devices, whereas bilingual connectors can support
both 1394b and 1394a devices. As
Figure 14.16
shows, the connectors and cables have
the same pinout but are keyed differently.
Figure 14.16
Bilingual and beta 1394b connectors and cables. Many 1394b implementations use both
types of connectors.
Notethatbilingualsocketsandcableshaveanarrowernotchthanbetasocketsandcables.
This prevents cables designed for 1394a devices from being connected to the beta socket.
Figure 14.17
compares a beta-to-beta 1394b cable to bilingual-to-1394a cables.
