Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!mailrus!ulowell!tegra!vail
From: vail@tegra.UUCP (Johnathan Vail)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Need DMA channel information.
Message-ID: <530@atlas.tegra.UUCP>
Date: 12 Jun 89 15:58:23 GMT
References: <27528@mirror.UUCP>
Organization: Tegra, Inc., Billerica, MA
Lines: 33
In-reply-to: mguyott@mirror.UUCP's message of 9 Jun 89 21:50:06 GMT

In article <27528@mirror.UUCP> mguyott@mirror.UUCP (Marc Guyott) writes:

   IRQ  0 - Timer.
   IRQ  1 - Keyboard.
   IRQ  2 - EGA vertical retrace.
   IRQ  3 - COM2.
   IRQ  4 - COM1.
   IRQ  5 - Fixed disk.
   IRQ  6 - Diskette.
   IRQ  7 - LPT1.
   IRQ  8 - Real time clock.
   IRQ  9 - LAN adapter 1.
   IRQ 10 - Reserved.
   IRQ 11 - Reserved.
   IRQ 12 - Mouse.
   IRQ 13 - Coprocessor.
   IRQ 14 - Fixed Disk.
   IRQ 15 - Reserved.

Something seems wrong about the above but I don't have the info in
front of me (just this frontal lobotomy).  PC/XT only have IRQs 0-7.
ATs have 8-15.  On an AT IRQ 2 is the cascaded output from the second
interrupt controller (IRQ8-15).  Also, I believe that IRQ5 is LPT2:.
Maybe the EGA shares the IRQ and software if smart enough to figure
out who really interrupted.  Also, maybe an XT can only have one
paralell port?  Maybe someone (myself when I bring the info in to
work) will repost this with the distinctions between AT and XT.

"Always Mount a Scratch Monkey"
 _____
|     | Johnathan Vail | tegra!N1DXG@ulowell.edu
|Tegra| (508) 663-7435 | N1DXG@145.110-,145.270-,444.2+,448.625-
 -----