Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!apollo!ulowell!tegra!vail
From: vail@tegra.UUCP (Johnathan Vail)
Newsgroups: comp.sys.ibm.pc
Subject: Re: COM ports - I am still confused!!!
Message-ID: <536@atlas.tegra.UUCP>
Date: 23 Jun 89 14:23:00 GMT
References: <29697@ucbvax.BERKELEY.EDU> <6049@microsoft.UUCP> <645@octopus.UUCP>
Organization: Tegra, Inc., Billerica, MA
Lines: 24
In-reply-to: pete@octopus.UUCP's message of 21 Jun 89 07:43:06 GMT

In article <645@octopus.UUCP> pete@octopus.UUCP (Pete Holzmann) writes:

   More specifically: LPT1 can be any of several I/O ports, depending on which
   hardware you have. DOS checks for 3 standard LPT addresses (3BC, 278 and
                      ^^^
   378, in that order), and fills in a table starting at 40:8 with whichever

   DOS checks for the normal COM1/COM2 addresses (2F8, 3F8) and fills in a table
   ^^^
   at 40:0. This is fine, but by universal common convention, the table is

Is it really DOS that does this or BIOS?  Memory at segment 40 is the
BIOS data area and I was wondering if DOS is the one that mormally
goes in and sets this up (of course I am sure that it can and does on
occasion but is this supposed to be true?).

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|     | Johnathan Vail | tegra!N1DXG@ulowell.edu
|Tegra| (508) 663-7435 | N1DXG@145.110-,145.270-,444.2+,448.625-
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