LOCAL I/O OPERATIONWhen an application requests I/O services, the underlying operating system calls device driver software that is resident in BIOS on most MS-DOS PCs. Device driver software is written to communicate with the device controller card, and can thus forward the I/O request to firmware that is resident on the controller.The device controller then provides the required control signals to the device. Additional query words:
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Last Reviewed: September 24, 1999 © 2000 Microsoft Corporation. All rights reserved. Terms of Use. |