Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!purdue!ames!eos!shelby!polya!Polya.Stanford.EDU
From: stanton@Polya.Stanford.EDU (Scott Stanton)
Newsgroups: comp.sys.ibm.pc
Subject: AT keyboards, ports, and other things
Message-ID: <10146@polya.Stanford.EDU>
Date: 21 Jun 89 02:36:47 GMT
Sender: Scott Stanton <stanton@polya.Stanford.EDU>
Reply-To: stanton@Polya.Stanford.EDU (Scott Stanton)
Organization: Stanford University
Lines: 15

Is it possible for an extended (101 key) keyboard to do chording on an
AT (clone)?  i.e. Can I detect if more than one key is being pressed
at the same time?  I have no qualms about going straight to the
hardware interrupts on this one, assuming I can find any info on
those.

Which brings me to my next question:  Could someone provide me
with a description of how INT 9H works?  Is it triggered by both
key press and key release?  How do I query the keyboard to
determine which key(s) are currently being held down?  I assume
the info is available on some port, but I'm having trouble
finding any books that will tell me anything about this.  (or
anything about ports at all, for that matter)

--Scott (stanton@polya.stanford.edu)