#include "EXTERN.h"
#include "perl.h"
#include "conio.h"
#include "XSUB.h"

MODULE = InOut        PACKAGE = InOut

IV inp(IV p)
    CODE:
    {
      RETVAL = inp( (unsigned short) p);
    }
    OUTPUT:
    RETVAL

void outp(IV p, IV v)
    CODE:
    {
      outp((unsigned short) p, (unsigned char) v);
    }

IV inpw(IV p)
    CODE:
    {
      RETVAL = inp( (unsigned short) p);
    }
    OUTPUT:
    RETVAL

void outw(IV p, IV v)
    CODE:
    {
      outp((unsigned short) p, (unsigned short) v);
    }

IV inpd(IV p)
    CODE:
    {
      RETVAL = inp( (unsigned short) p);
    }
    OUTPUT:
    RETVAL

void outpd(IV p, IV v)
    CODE:
    {
      outp((unsigned short) p, (unsigned long) v);
    }
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package InOut;

require 5.005_92;
use strict;
use warnings;

require Exporter;
require DynaLoader;

our @ISA = qw(Exporter DynaLoader);
our @EXPORT_OK = qw(inp outp inpw outpw inpd outpd);
our $VERSION = '1.00';

bootstrap InOut $VERSION;

1;
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use InOut;

$b = inp($port);
$w = inpw($port);
$d = inpd($port);

outp($port, $b);
outpw($port, $w);
outpd($port, $d);
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Thanks for your help. Here is an update:
MakeMaker (ActiveState 5.8.0) hates spaces where perl.exe's path is concerned or I am to stupid to figure out a way to fix its problem with "C:\Program Files\perl".
Uninstalled perl. Re-installed in "C:\perl" and got a little farther.

While linking I got unresolved references.
Tried coping msvcrt.lib & conio.h everywhere. No luck. I found 'libpth' in Config.pm and 'libpath' in Makefile but changes there didn't work. There is more with the libs but the answer was:
In the XS code above I needed '_inp' not 'inp' (and the same for the rest). My fault for not mentioning I'm on a Windows 2000 machine. :(

Now I just have to figure out the way around NT complaining with STAUS_PRIVILEGED_INSTRUCTION when I use outp. :| Ugh.

Does anyone know how to get it to work in kernel mode instead of user? That should probably be a new question.

While linking I got unresolved references.

Opps, forgot to mention that you need to compile/link in release mode as inp and outp will not work in debug mode.

Now I just have to figure out the way around NT complaining with STAUS_PRIVILEGED_INSTRUCTION when I use outp.

You could use a Windows NT/2000/XP I/O Port device driver to do the port I/O on your behalf. Have a look at the following article which gives an insight to the problem and solution.