Chapter 4

MANAGING DEVICES AND

PERIPHERALS

Device Manager

Provides a graphic view of hardware installed on the computer

Helps to manage and trouble shoot the hardware

Shows whether hardwire is working properly

Automatic Installation of Hardware

Plug-and-Play (PNP) has changed the way we install hardware

Manual installation of hardware is a thing of the past

All you need to install PNP hardware isThe hardwareThe driverThe directions

Automatic Installation of Hardware

The Plug and Play (PnP) basic input/output system (BIOS) automatically identifies PnP devices and arbitrates their resource requests.

The resource allocation among PnP devices is not permanent.

If another PnP device requests a resource that has already been allocated, the BIOS again arbitrates the requests to satisfy all of them.

Automatic Installation of Hardware

After startup, Windows XP takes over management of devices and might again change one or more assignments to suit its own requirements

Troubleshooting Installations

The best way to avoid problems with the installation of hardware is to follow the manufactures instructions

Although you can run into problems with their instructions.

Troubleshooting Installations

If you see any of the icons indicating a hardware problem try the following

Open the Properties dialog box for the device. The General tab lists the status of the device and lets you launch a device troubleshooter.

Troubleshooting Installations

Consult the manufacturer’s instructions to verify that you have performed all necessary steps to configure the device

Right-click the device and select Uninstall. Restart Windows, and allow it to detect the device again.

Hardware Resources

Hardware resources are used by the hardware to communicate with the operating system

They are Interrupts Input/Output (I/O) portsDirect Memory Access (DMA) channels

Hardware Resources

Hardware resources are dynamically changed in the PNP process

It is important to remember not to change the resources of a PNP device because this can have and effect on the dynamic process

Interrupts

Hardware devices must get the processor’s attention to send messages.

The microprocessor knows this process as an interrupt request (IRQ)

The microprocessor uses this information to determine which device needs its attention and the type of attention that it needs.

Interrupts

Modern computers have minimum of 15 interrupts

Computers with Advanced Programmable Interrupt Controllers (APICs) can have up to 24 IRQs,

Input/Output (I/O) Ports

I/O ports are a section of memory that a hardware device uses to communicate with the operating system.

When a microprocessor receives an interrupt request via an IRQ, the operating system checks the I/O port address to retrieve additional information about what the hardware device wants it to do.

Direct Memory Access (DMA) channels DMA channels allow a hardware device,

such as a floppy disk drive, to access memory directly, without interrupting the microprocessor.

DMA channels speed up access to memory

Direct Memory Access (DMA) channels Modern computers have eight DMA

channels, numbered 0 through 7 DMA channels are managed by the

motherboard’s chipset or by devices that have their own DMA controller.