How does INT 16 know that INT 9 has executed?

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#1479

From: Yossi Gil
Date: Sun, 13 Sep 1992 05:31

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Suppose you call int 16 with ah=0 and that there are no
keys in the keyboard queue. Int 16 codes then waits for
a keystroke to occur and return it.

Q:  What is the communication mechanism? How does int 9 signal
to int 16 that a keystroke occured. 

I did few experiments and as far as I can tell, int 16 doesn't loop
until head != tail for the keyboard queue. 

--
Joseph (Yossi) Gil                 {alberta,uw-beaver,uunet}!ubc-cs!yogi
Dept. of Computer Science          yogi@cs.ubc.ca (cs.ubc.ca=137.82.8.5)
6356 Agricultural Road., Univ. of B.C.,             Tel: +1-604-822-8175
Vancouver, British Columbia, V6T 1Z2, Canada.       Fax: +1-604-822-5485

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Path: arc1-ca.pugleaf.net!sparky!uunet!spool.mu.edu!sol.ctr.columbia.edu!destroyer!ubc-cs!yogi
From: yogi@cs.ubc.ca (Yossi Gil)
Subject: How does INT 16 know that INT 9 has executed?
Message-ID: <1992Sep13.053140.12086@cs.ubc.ca>
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Organization: Computer Science, University of B.C., Vancouver, B.C., Canada
Date: Sun, 13 Sep 92 05:31:40 GMT
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