PC Hardware A Beginner’s Guide

External Ports and Connectors Although the basic set of external ports on a PC has settled into a sort of standard, it can vary ...

cial characters, and numbers of American English. Table 19-1 includes a sampling of ASCII characters showing the binary and deci ...

Serial and Parallel Data Data is transmitted and moved in one of two formats: parallel or serial. Parallel data is sent one char ...

Full, Half, and Single Modes Depending on the mode of the communications line, two devices may be restricted or completely free ...

(^484) PC Hardware: A Beginner’s Guide ports, and communications are based on the principle that serial data is transmitted one ...

Chapter 19: Ports and Connectors^485 A serial cable, like all PC cables, is made u pof a wire cable that has as few as 2 wires a ...

These bits mark the beginning and ending of each character transmitted. The start bit has a value of 0, and the stop bit is set ...

 Converting the received serial bit stream into parallel data for transmission over the PC’s internal data bus On the PC, the d ...

The UARTs above the 16550 are used in various types of high-speed and multiport adapter cards and devices, such as ISDN and DSL ...

Chapter 19: Ports and Connectors^489 The DTE signals over its Request to Send (RTS) line requesting the DCE to send any data it ...

system resource assignments used for the serial ports on most PCs. Notice that COM1 shares an IRQ with COM3 and COM2 shares an I ...

Parallel Ports Parallel ports are much more straightforward than serial ports. Because all of a charac- ter’s data moves over a ...

better known as the IEEE 1284 standard. IEEE 1284 incorporates the two pre-existing par- allel port standards that were already ...

The USB Interface When the PC had only a printer or a modem connected to it, one or two serial and parallel ports were enough to ...

The USB interface supports up to 127 devices on a single channel. Most PCs have only one or two USB connectors, as illustrated i ...

Chapter 19: Ports and Connectors^495 Figure 19-10. Connecting to a USB port on a PC Figure 19-11. Multiple USB devices can be co ...

The USB Interface A USB interface has three essential components: a host, a hub, and peripheral devices.
USB host A PC is the ...

Several manufacturers have implemented the IEEE 1394 standard largely as propri- etaryandlicensedinterfaces.Themorepopularofthes ...

(^498) PC Hardware: A Beginner’s Guide FireWire Device Drivers Virtually all of the later versions of popular operating systems, ...

is blocking the path, you must move either the obstruction or the controller to reopen the line-of-sight. Using an IR connection ...