Windows Server 2008 - Understanding resources

Computers provide a number of resources. Some resources are dynamic. When you start an application, it allocates memory from a pool of memory that the server provides. However, other resources are static. The server allocates the resources to address specific needs. Most hardware uses static resources in one of four categories:

• Memory
• I/O
• IRQ
• DMA

The hardware relies on the memory to perform tasks, just as applications do. For example, a display adapter uses memory to store images that you eventually see on the monitor. The processor communicates with a particular piece of hardware using a specific I/O address. When a piece of hardware needs to communicate with the processor, it relies on an IRQ. Hardware may also need to transfer data from its own, “personal” memory to the system memory using DMA. DMA provides data transfers between main memory and device memory without interrupting the CPU. You can view resources by type or connection. Sometimes you want to view the resources used by a particular device. In this case, right-click the device you want to view and choose Properties from the context menu. Select the Resources tab and you see a listing of the resources used by that device.

Notice that this device, the Standard VGA Graphics Adapter, has both memory and I/O range resource requirements. In addition, the system tells you that this device isn’t conflicting with any other device on the system, which means that no two devices require the same memory or I/O range.

All the entries you see are in hexadecimal (base 16) because that’s how the computer thinks about the resources. If you ever need to change any of the resource settings, you also need to think in hexadecimal. Normally, hexadecimal entries appear with 0x in front of them. For example, 0xF is a hexadecimal value with the decimal value 15. However, all values in Device Manager are in hexadecimal, even if they aren’t preceded by 0x.

Most devices have standardized settings. For example, communications port 1 (COM1) normally uses an I/O range of 0x03F8 to 0x3FF and an IRQ of 4. A standard computer can have up to four COM ports, each of which has its own standard settings. The same statement holds true for parallel (LPT) ports and many other devices. Windows stores these settings in the information (INF) files associated with the device. If you need to use an alternative setting, clear the Use Automatic Settings option and you find that you can choose from one of the recognized alternatives. In this case, the COM port can use one of eight alternative settings.

In very rare circumstances, you can provide custom settings for a particular device. To make this happen, you must clear the Use Automatic Settings option and choose one of the resources. For example, you might choose to change the IRQ for the COM port. Click Change Settings and you see an Edit Interrupt Request dialog box, where you can choose a different IRQ. Device Manager tells you whether any other devices are using the setting you choose. In some cases, you might have to disable one device to make room for another — although this, too, is extremely rare when working with Windows Server 2008.


The settings you change in Device Manager aren’t arbitrary. The hardware must have the required configuration to accept the new settings. For example, if a serial card has settings for only IRQ 3 and IRQ 4, then you can’t set the card for IRQ 5 in Device Manager and expect it to work. The settings in Device Manager define the physical interface between the Windows drivers and the hardware. Normally, you want to stick with the automatic settings when you can, and use the standard configurations provided by the device vendor when the automatic configuration fails. Avoid providing custom settings unless you truly know which settings the device accepts.


An easy technique for converting between hexadecimal and decimal
Most people don’t think about numbers in hexadecimal. In fact, making the transition can prove difficult, even when you need to use hexadecimal for every task. Fortunately, Windows provides an easy method of converting between decimal and hexadecimal: the Calculator utility. To start this utility, choose Start -> Programs -> Accessories -> Calculator. When you see the Calculator utility, choose View -> Scientific. Notice that Calculator view changes to include a number of new features, including Hex and Dec options. Conversions are easy: To convert a number from decimal to hexadecimal, click Dec, type the decimal value you want to convert, and then click Hex. The number automatically changes from decimal to hexadecimal form. Likewise, if you want to convert a number from hexadecimal to decimal, click Hex, type the hexadecimal value you want to convert, and then click Dec.


Source of Information : For Dummies Windows Server 2008