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From: Ralf.Brown@B.GP.CS.CMU.EDU
Newsgroups: comp.os.msdos.programmer
Subject: Re: COM1 COM2 interrupt numbers?
Message-ID: <27016283@ralf>
Date: 27 Sep 90 02:22:59 GMT
Sender: ralf@b.gp.cs.cmu.edu
Organization: Carnegie Mellon University School of Computer Science
Lines: 23
In-Reply-To: <Iaw_cB600VY6IMyqUW@andrew.cmu.edu>

In article <Iaw_cB600VY6IMyqUW@andrew.cmu.edu>, jc58+@andrew.cmu.edu (Johnny J. Chin) wrote:
}INT 0 - NMI (non-maskable interrupt) - usually due to memory parity error
}INT 1 - reserved
}INT 2 - used by many EGA/VGA cards (usually available on 8088)
}        cascading interrupt on 286/386/486 machines
}INT 3 - COM2:
}INT 4 - COM1:
}INT 5 - Hard Disk Controller on 8088 (available for LPT2: on 286/386/486)
}INT 6 - Floppy Controller
}INT 7 - LPT1:
}
}INT 14 - cascaded off INT 2 - Hard Disk Controller on 286/386/486.

Read IRQ instead of INT for all of the above (IRQ0-7 are normally programmed
to appear as INT 08-0F and IRQ8-15 as INT 70-77).  Secondly, NMI is *not*
tied to any IRQ (it is INT 02).  IRQ0 is the system clock tick and IRQ1 is
the keyboard interrupt.

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