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Path: utzoo!watmath!clyde!cbosgd!ihnp4!drutx!mtuxo!mtuxt!dmt
From: dmt@mtuxt.UUCP (D.TUTELMAN)
Newsgroups: net.micro.pc
Subject: re: 8259 PIC
Message-ID: <640@mtuxt.UUCP>
Date: Sun, 20-Apr-86 08:36:50 EST
Article-I.D.: mtuxt.640
Posted: Sun Apr 20 08:36:50 1986
Date-Received: Mon, 21-Apr-86 07:49:48 EST
Organization: AT&T Information Systems, Holmdel NJ
Lines: 32

> From: nadji@uscvax.UUCP (Behzad Nadji)
> Newsgroups: net.micro.pc
> Date: Thu, 10-Apr-86 19:38:46 EST
> Organization: CS&CE Depts, U.S.C., Los Angeles, CA
> 
> "One can send a EOI to 8259 PIC by writing a 20H into port 20H."
> 
> Where can I get more detail on this?
> 
> [ ... references to a number of non-helpful sources ... ]
> 
> 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.

I didn't see in any of the replies so far reference to an excellent
article on the subject by Chris Dunford (yes, the author of CED).
Check out the PC Tech Journal for Nov/Dec 1983, pp 173-199.

The article concentrates on how the 8259 is used in the PC, and thus prunes
out some information (no doubt interesting, but not relevant) that you'd
have to wad through in the Intel spec sheet.  (But don't throw away the
spec sheet; IT'S the primary reference source.)

             		Dave Tutelman
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