DOS Device Drivers DOS Devices may be accessed by Int 21 Function calls which support file I/O by specifying the name of a device rather than a file or by useing the Handle Read and Write functions with the STDIN, STDOUT, and STDERR devices which are set to handles 0, 1, and 2 respectfully when dos loads any program. Some Device drivers also add new Interrupt Functions to the DOS or BIOS. Console Input and Output Clock device Physical Communication Drivers Logical Communication Device Physical Printer Logical Printer see also: BIOS Device Drivers Handle Close Int21円F3円E Handle Open Int21円f3円D Handle Read Int21円f3円F Handle Write Int21円f40円 IOCTL
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