External Ports and Connectors
Although the basic set of external ports on a PC has settled into a sort of standard, it can
vary from PC to PC. The standard set includes a serial port or two, a parallel port or two,
USB ports or FireWire ports, a video port, a game device port, and speaker and micro-
phone jacks, as illustrated in Figure 19-4. These are the ports and connectors that are the
focus of this chapter.
These interfaces are each explained, right after some background information that
will help you to understand how the interfaces work.Character Data
So, what does character data have to do with ports and connectors? Well, in order to un-
derstand many of the principles of data communications, you must first understand the
data being communicated. Data on a PC is stored in a format defined in the American
Standard Code for Information Interchange or ASCII (pronounced “askie”). ASCII de-
fines the standard character set used on PCs, which includes special command, inquiry,
and graphics characters along with the upper- and lowercase alphabetic characters, spe-(^480) PC Hardware: A Beginner’s Guide
Figure 19-3. Peripheral device connectors located on a motherboard