Dma direct memory access channels are conduits used

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sharing of an IRQ; older (legacy) devices had to be assigned a unique IRQ. DMA (Direct Memory Access) channels are conduits used by high-speed devices to bypass the CPU and communicate directly with RAM. o Devices such as hard drives, sound cards, and FireWire cards use DMA channels to increase the speed of data transfers. o Devices must have a unique DMA channel. An I/O address (also known as a port address ) allows two devices in a computer to send information to each other. o When a device wants to send information to another device, it addresses the data to the receiving I/O port number and sends it out on the system bus. o Each device in a computer must have its own I/O address. Plug and play Newer systems use plug and play to automatically configure the resources used by each device. Be aware of the following when using plug and play: The device, the BIOS, and the operating system must support plug and play standards. All new devices and operating systems are plug and play compatible. Plug and play allows for IRQ sharing and ensures that DMA and I/O resources used by each device are unique. A legacy device is one that does not support Plug and Play. In older systems, you had to manually configure the resources used by each device. Troubleshooting of legacy systems often involved finding and resolving resource conflicts. Although a plug and play system attempts to assign configuration resources around the needs of legacy devices, legacy devices often interfere with a plug and play system's ability to properly assign resources. Driver A driver is program that enables the operating system to interact with hardware devices. Plug and play does not replace the need for a driver; the operating system still requires a driver to be able to configure and use the device. Windows detects newly installed devices and tries to find and load the driver automatically. o Many drivers are automatically included with the operating system. o Some drivers are preinstalled during the operating system installation. Windows will
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automatically use preinstalled drivers when they match new devices. o Windows can search the Internet for some drivers. o If Windows cannot find a suitable driver, you are prompted to identify alternate locations to search in order to find the correct driver. Signed drivers are drivers that include a digital signature. The digital signature proves that the driver: o Comes from the reported publisher o Has not been altered or modified o Is compatible with the operating system version Drivers that have passed specific tests on Windows qualify for the Certified for Windows logo and are given a special digital signature. An unsigned driver is one without a digital signature; a self-signed driver is one that includes a digital signature, but the identity of the entity that signed the driver cannot be verified. You can install unsigned or self-signed drivers.
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