barcode scanner for java Mike Meyers A+ Guide to Managing and Troubleshooting PCs in Software

Encoder QR Code ISO/IEC18004 in Software Mike Meyers A+ Guide to Managing and Troubleshooting PCs

Mike Meyers A+ Guide to Managing and Troubleshooting PCs
Decoding QR Code In None
Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications.
Draw Denso QR Bar Code In None
Using Barcode creator for Software Control to generate, create QR image in Software applications.
ROM Motherboards store the keyboard controller support programming, among other programs, on a special type of device called a read-only memory (ROM) chip A ROM chip stores programs exactly like RAM: that is, like an 8-bit-wide spreadsheet But ROM differs from RAM in two important ways First, ROM chips are non-volatile , meaning that the information stored on ROM isn t erased when the computer is turned off Second, traditional ROM chips are read-only, meaning that once a program is stored on one, it can t be changed Modern motherboards use a type of ROM called flash ROM that differs from traditional ROM in that you can update and change the contents through a very specific process called flashing the ROM, covered later in this chapter Figure 58 shows a typical flash ROM chip on a motherboard When the CPU Figure 58 Typical flash ROM wants to talk to the keyboard controller, it goes to the flash ROM chip to access the proper programming (Figure 59) Every motherboard has a flash ROM, called the system ROM chip because it contains code that enables your CPU to talk to the basic hardware of your PC As alluded to earlier, the system ROM holds BIOS for more than just the keyboard controller It also stores programs for communicating with the floppy drives, hard drives, optical drives, video, USB ports, and other basic devices on your motherboard
QR Code ISO/IEC18004 Recognizer In None
Using Barcode decoder for Software Control to read, scan read, scan image in Software applications.
Denso QR Bar Code Creator In C#.NET
Using Barcode drawer for .NET Control to generate, create QR-Code image in VS .NET applications.
Figure 59
QR Code Maker In .NET
Using Barcode creation for ASP.NET Control to generate, create QR Code 2d barcode image in ASP.NET applications.
QR Code 2d Barcode Printer In .NET
Using Barcode encoder for .NET framework Control to generate, create QR Code ISO/IEC18004 image in .NET framework applications.
Function of the flash ROM chip
Encoding QR Code In Visual Basic .NET
Using Barcode creator for Visual Studio .NET Control to generate, create QR image in Visual Studio .NET applications.
Print Data Matrix In None
Using Barcode creation for Software Control to generate, create Data Matrix 2d barcode image in Software applications.
5: BIOS and CMOS
Printing UPCA In None
Using Barcode generation for Software Control to generate, create UPC Code image in Software applications.
EAN 128 Creator In None
Using Barcode generator for Software Control to generate, create UCC.EAN - 128 image in Software applications.
Programs stored on ROM chips flash or any other kind of ROM chip are known collectively as firmware, as opposed to programs stored on erasable media that are collectively called software
Barcode Generator In None
Using Barcode generator for Software Control to generate, create barcode image in Software applications.
Generating Code 128 Code Set B In None
Using Barcode generation for Software Control to generate, create Code-128 image in Software applications.
To talk to all of that hardware requires hundreds of little services (2 to 30 lines of code each) These hundreds of little programs stored on the system ROM chip on the motherboard are called, collectively, the system BIOS (See Figure 510) Techs call programs stored on ROM chips of any sort firmware The system ROM chips used on modern PCs store as much as 2 MB of programs, although only 65,536 bytes are used to store the system BIOS This allows for backward compatibility with earlier systems The rest of the ROM space is put to good use doing other jobs
Paint DUN - 14 In None
Using Barcode drawer for Software Control to generate, create DUN - 14 image in Software applications.
Code 128 Printer In VS .NET
Using Barcode printer for Reporting Service Control to generate, create Code 128 Code Set B image in Reporting Service applications.
System BIOS Support
Generate Linear 1D Barcode In Visual Basic .NET
Using Barcode generation for Visual Studio .NET Control to generate, create 1D image in VS .NET applications.
Code 39 Full ASCII Maker In Java
Using Barcode encoder for Java Control to generate, create Code 39 Extended image in Java applications.
Every system BIOS has two types of hardware to support First, the system BIOS supports all the hardware that never changes, such as the keyboard (You can change your keyboard, but you can t change the keyboard controller built into the Southbridge) Another example of hardware that never changes is the PC speaker (the tiny one that beeps at you, not the ones that play music) The system ROM chip stores the BIOS for these and other devices that never change Second, the system BIOS supports all the hardware that might change from time to time This includes RAM (you can add RAM), hard drives (you can replace your hard drive with a larger drive or add a second hard drive), and floppy drives (you can add another floppy drive) The system ROM chip stores the BIOS for these devices, but the system needs another place to store information about the specific details of a piece of hardware This enables the system to differentiate between a Western Digital Caviar 500-GB hard drive and a Seagate Barracuda 60-GB drive, and yet still support both drives right out of the box
Drawing Barcode In Java
Using Barcode printer for Java Control to generate, create bar code image in Java applications.
UCC-128 Generator In C#
Using Barcode creation for .NET Control to generate, create EAN / UCC - 14 image in .NET framework applications.
Figure 510
Encode Code 128 Code Set C In VB.NET
Using Barcode drawer for Visual Studio .NET Control to generate, create Code-128 image in .NET applications.
Generate EAN / UCC - 14 In Objective-C
Using Barcode encoder for iPhone Control to generate, create EAN 128 image in iPhone applications.
CPU running BIOS service
Mike Meyers A+ Guide to Managing and Troubleshooting PCs
CMOS
A separate memory chip, called the complementary metal-oxide semiconductor (CMOS) chip, stores the information that describes specific device parameters CMOS does not store programs; it only stores data that is read by BIOS to complete the programs needed to talk to changeable hardware CMOS also acts as a clock to keep the current date and time Years ago, CMOS was a separate chip on the motherboard, as Figure 511 Old-style CMOS shown in Figure 511 Today, the CMOS is almost always built into the Southbridge Most CMOS chips store around 64 KB of data, but the PC usually needs only a very small amount about 128 bytes to store all the necessary information on the changeable hardware Don t let the tiny size fool you The information stored in CMOS is absolutely necessary for the PC to function! If the data stored on CMOS about a particular piece of hardware (or about its fancier features) is different from the specs of the actual hardware, the computer will not be able to access that piece of hardware (or use its fancier features) It is crucial that this information be correct If you change any of the previously mentioned hardware, you must update CMOS to reflect those changes You need to know, therefore, how to change the data on CMOS
Copyright © OnBarcode.com . All rights reserved.