Is it possible to address high Ports with Inpout32.dll?

Question

I want to address Port 0xE020 (Hex -> Dec = 57.376) but it is out of bounds for a short. Now, I need this to test PCI-E Extension Parallel Ports.

Thanks to the answer to this question (https://stackoverflow.com/a/4618383/3391678) I use the following working code for 32-bit environments:

using System;
using System.Runtime.InteropServices;

namespace LPTx86
{
    public class LPT
    {
        //inpout.dll

        [DllImport("inpout32.dll")]
        private static extern void Out32(short PortAddress, short Data);

        [DllImport("inpout32.dll")]
        private static extern char Inp32(short PortAddress);

        private short _PortAddress;

        public LPT(short PortAddress)
        {
            _PortAddress = PortAddress;
        }

        public void Write(short Data)
        {
            Out32(_PortAddress, Data);
        }

        public byte Read()
        {
            return (byte)Inp32(_PortAddress);
        }
    }
}

And for 64-bit environments:

using System;
using System.Runtime.InteropServices;

namespace LPTx64
{
    class LPT
    {
        [DllImport("inpoutx64.dll", EntryPoint = "Out32")]
        private static extern void Out32_x64(short PortAddress, short Data);

        [DllImport("inpoutx64.dll", EntryPoint = "Inp32")]
        private static extern char Inp32_x64(short PortAddress);

        private short _PortAddress;

        public LPT64(short PortAddress)
        {
            _PortAddress = PortAddress;
        }

        public void Write(short Data)
        {
            Out32_x64(_PortAddress, Data);
        }

        public byte Read()
        {
            return (byte)Inp32_x64(_PortAddress);
        }
    }
}

(Yes, I removed every piece of safeties and sanity checking, my second name is "Danger" ;) )

Is it possible and how can I address ports that do not fit into a short?

Use `ushort` to get ahead, the port number is not a signed value. — Hans Passant, Oct 14 '16 at 11:02
i looked into the header files and yes, it's ushort, i better correct that before something breaks... — Dennis Christian, Oct 17 '16 at 09:44

score 1 · Answer 1 · answered Aug 07 '19 at 15:08

My header looks like this

void    _stdcall Out32(short PortAddress, short data);
short   _stdcall Inp32(short PortAddress);

The accepted answer works, but I think a more idiomatic way of using longer addresses is keeping the signatures consistent and casting to short in an unchecked context

[DllImport("inpout32.dll")]
private static extern void Out32(short PortAddress, short data);

[DllImport("inpout32.dll")]
private static extern short Inp32(short PortAddress);

public void Write(int address, short data) {
    short portAddress;
    unchecked {
        portAddress = (short)address;
    }
    Out32(portAddress, data);
}

public short Read(int address) {
    short portAddress;
    unchecked {
        portAddress = (short)address;
    }
    return Inp32(portAddress);
}

Dennis Christian · Accepted Answer · 2016-10-14T08:04:02.943

It's possible:

I tried and changed the type of the port variable from short to int, i tested it and it seems to work:

Edit: Refactored Code to combine the data/control/status ports into one Package

using System;
using System.Runtime.InteropServices;

namespace LPTtestdrive
{
    class LPT_X
    {
        //inpout.dll

        [DllImport("inpout32.dll")]
        private static extern UInt32 IsInpOutDriverOpen();

        [DllImport("inpout32.dll")]
        private static extern void Out32(int PortAddress, short Data);

        [DllImport("inpout32.dll")]
        private static extern char Inp32(int PortAddress);

        //inpoutx64.dll

        [DllImport("inpoutx64.dll", EntryPoint = "IsInpOutDriverOpen")]
        private static extern UInt32 IsInpOutDriverOpen_x64();

        [DllImport("inpoutx64.dll", EntryPoint = "Out32")]
        private static extern void Out32_x64(int PortAddress, short Data);

        [DllImport("inpoutx64.dll", EntryPoint = "Inp32")]
        private static extern char Inp32_x64(int PortAddress);

        private bool _X64;
        private int DataAddress;
        private int StatusAddress;
        private int ControlAddress;

        public LPT_X(int PortAddress)
        {
            DataAddress = PortAddress;
            StatusAddress = (int)(DataAddress + 1);
            ControlAddress = (int)(DataAddress + 2);

            //now the code tries to determine if it should use inpout32.dll or inpoutx64.dll
            uint nResult = 0;

            try
            {
                Console.WriteLine("trying 32 bits");
                nResult = IsInpOutDriverOpen();
                if (nResult != 0)
                {
                    Console.WriteLine("using 32 bits");
                    return;
                }
            }
            catch (BadImageFormatException)
            {
                Console.WriteLine("32 bits failed");
            }
            catch (DllNotFoundException)
            {
                throw new ArgumentException("Unable to find InpOut32.dll");
            }
            catch (Exception exc)
            {
                Console.WriteLine(exc.Message);
            }

            try
            {
                Console.WriteLine("trying 64 bits");
                nResult = IsInpOutDriverOpen_x64();
                if (nResult != 0)
                {
                    Console.WriteLine("using 64 bits");
                    _X64 = true;
                    return;
                }
            }
            catch (BadImageFormatException)
            {
                Console.WriteLine("64 bits failed");
            }
            catch (DllNotFoundException)
            {
                throw new ArgumentException("Unable to find InpOutx64.dll");
            }
            catch (Exception exc)
            {
                Console.WriteLine(exc.Message);
            }

            throw new ArgumentException("Unable to open either inpout32 and inpoutx64");
        }

        public void WriteData(short Data)
        {
            if (_X64)
            {
                Out32_x64(DataAddress, Data);
            }
            else
            {
                Out32(DataAddress, Data);
            }
        }

        public void WriteControl(short Data)
        {
            if (_X64)
            {
                Out32_x64(ControlAddress, Data);
            }
            else
            {
                Out32(ControlAddress, Data);
            }
        }

        public byte ReadData()
        {
            if (_X64)
            {
                return (byte)Inp32_x64(DataAddress);
            }
            else
            {
                return (byte)Inp32(DataAddress);
            }
        }

        public byte ReadControl()
        {
            if (_X64)
            {
                return (byte)Inp32_x64(ControlAddress);
            }
            else
            {
                return (byte)Inp32(ControlAddress);
            }
        }

        public byte ReadStatus()
        {
            if (_X64)
            {
                return (byte)Inp32_x64(StatusAddress);
            }
            else
            {
                return (byte)Inp32(StatusAddress);
            }
        }
    }
}

Use it like this:

LPT_X LPT;
int read;
int Adress = 0xE020;
try
{
    LPT = new LPT_X(Address);
    LPT.WriteData(251);
    LPT.WriteControl(0);

    read = LPT.ReadStatus();
    ...
}

Is it possible to address high Ports with Inpout32.dll?

2 Answers2