Chr 

This tells the driver to return its output status; in particular, to

indicate whether an output request can be satisfied without waiting.

DevReq0aRec

Offset Size Contents

+0      1  bLen         0dH (length of this request packet)

+1      1  bUnitNo      (not used)

+2      1  bCmd         0aH (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 the driver is unable to accept any additional characters,

set the Busy bit (bit 9).  Otherwise, clear bit 9 to indicate

that a call to DvRq 08H will be satisfied without waiting.

Notes:   Output devices can be optimized by processing DvRq 10H (output

until busy).

See Also: Device Requests

DevRequestHdrRec

Installable Device Drivers

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