Device Request 06H: Input Status
This tells the driver to return its input status; in particular, to
indicate whether there are characters in the device input buffer ready for
Offset Size Contents
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+0 1 bLen 0dH (length of this request packet)
+1 1 bUnitNo (not used)
+2 1 bCmd 06H (command code)
+3 2 rStatus OUTPUT: Device Status Word must fill before exit
+5H 8 res (reserved)
13 size of this structure
rStatus On exit, the driver must place a DevStatusWord here. Always
set the Done bit (bit 8).
If no characters are ready, set the Busy bit (bit 9).
Otherwise, clear bit 9 to indicate that a call to DvRq 04H
will be satisfied without waiting.
Notes: ■ This is the device driver "catch-point" for DOS fn 0bH (get
It is also called by DOS to avoid waiting in an input loop.
See Also: Device Requests
Installable Device Drivers