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Path: utzoo!linus!decvax!hplabs!sdcrdcf!uscvax!nadji
From: nadji@uscvax.UUCP (Behzad Nadji)
Newsgroups: net.micro.pc
Subject: 8259 PIC
Message-ID: <84@uscvax.UUCP>
Date: Thu, 10-Apr-86 19:38:46 EST
Article-I.D.: uscvax.84
Posted: Thu Apr 10 19:38:46 1986
Date-Received: Mon, 14-Apr-86 01:45:44 EST
Distribution: net
Organization: CS&CE Depts, U.S.C., Los Angeles, CA
Lines: 24

"One can send a EOI to 8259 PIC by writing a 20H into port 20H."

Where can I get more detail on this?
I have looked through the followings with no success:

   1) IBM PC TECH REF MANUAL
   2) IBM AT TECH REF MANUAL
   3) Norton's "Programmers Guide.."
   4) Dan Rollins' "IBM PC 8088 Assembler Prog."
   5) David Bradley's "Assembly Language Programming for the IBM PC"

The only place I found any reference to this was in Bradley's book
and that was very brief. And by looking at other peoples code and seeing 
that they all write a 20H to port 20H at the end of their interrupt handling 
routines.

Is there anything else to know about port 20H? Can anyone direct me
(exact pointers please) to find a little detail about this and related 
subjects.

Thanxs, 
nadji
                              ARPA:     nadji%usc-cse@csnet-relay.arpa
                              CSNET:    nadji@usc-cse.csnet