Datasheet

Identifying Characteristics of Ports and Cables
57
Audio jacks
ßN
PS/2 (mini-DIN)
ßN
Centronics
ßN
Let’s look at each one and how it is used.
FIGURE 1.37 RJ ports
Universal Serial Bus (USB)
Most computers built after 1997 have one or more flat ports in place of one DE9M
serial port. These ports are Universal Serial Bus (USB) ports, and they are used for con-
necting multiple (up to 127) peripherals to one computer through a single port (and the
use of multiport peripheral hubs). USB version 1.1 supported data rates as high as 12Mbps
(1.5MBps). USB 2.0 supports data rates as high as 480Mbps (60MBps), 40 times that of
its predecessor. Figure 1.38 shows an example of a set of Type A USB ports. Port types are
explained in the “Common Peripheral Interfaces and Cables” section later in this chapter.
USB 2.0 uses the same physical connection as the original USB, but it is
much higher in transfer rates and requires a cable with more shielding that
is less susceptible to noise. You can tell if a computer, hub, or cable sup-
ports USB 2.0 by looking for the red and blue “High Speed USB” graphic
somewhere on the computer, device, or cable (or on its packaging).
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