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Thread: Parallel ports in wiindows xp

  1. #1

    Default Parallel ports in wiindows xp

    hi my name is aditya.recently after reading the parallel port tutorials here,i decided to experiment it on my comp which is running xp.
    I downloaded porttalk22 which opens up any specific port in os like xp.
    http://<br /> <a href="</a><br />
    now, i wrote a the program in C and compiled it in borland TURBO C 2.01 running as
    #include <dos.h>
    #include <stdio.h>
    #include <stdlib.h>
    #define port 0x3BC
    #define value 0x00
    void main(void)
    outportb(port,value) ;
    The address of lpt1 can be found by running another c program which can be downloaded.
    The problem is though the program conmpiles and runs with porttalk perfectly i see no change in value of output in the parrallel port.It always reads 4.51v.
    Any help will be much appreciated.Thanks a lot.


  2. #2
    Member Advanced User
    Join Date
    Sep 2004



    Choose the DATA output port.
    Change the address to 0x378

    MIG India

  3. #3


    windows xp does not allow to access parallel port pins ....
    u have to either use windows 98 or u have to use bootble disc.
    Subhasis Behera
    If you are not living on the EDGE, then you are wasting space...

  4. #4

    Default Clarification

    hi ingenium and pulkit.thanks a lot for answering.i really didn't expect such a fast reply.
    But i think i have left out a fewthings.I am already using yhe pins 2-9 of lpt1(are those the DATA output pins?).Also i am using a hp computer and am 100% sure that my lpt1 is located at 0x3bc.
    and porttalk22 does open up ports on xp.I am not sure if i am llowed to but here's the readme file to it.

    Beyond Logic Port Talk I/O Port Driver

    The PortTalk driver combined with allowIO.exe, grants certain programs
    exclusive access to IO Ports on a Windows NT/2000/XP system.

    Important information for Upgrading PortTalk from V1.x
    __________________________________________________ ____

    When installing PortTalk V2.0 on machines with an older version
    of V1.x, the existing driver must be un-installed. Simply run
    uninstall.exe with administrator privileges.

    Installing PortTalk V2.0

    The PortTalk usermode programs now come with a self installer.
    This is built into allowio.exe and ioexample.exe. When these
    usermode programs are executed, a check is made if the PortTalk
    driver is started. If the driver is not started it attempts to
    install the driver and then start it.

    Allowio - Grants programs access to IO Ports.

    Usage : AllowIO <executable.exe> <Hex Addresse(s)> <Switches>

    eg. Using allowio to grant access to IO ports 0x42, 0x43 and 0x61

    C:\porttalk\AllowIO>allowio 0x42 0x43 0x61 beep.exe
    Beyond Logic AllowIO.EXE
    Address 0x042 (IOPM Offset 0x08) has been granted access.
    Address 0x043 (IOPM Offset 0x08) has been granted access.
    Address 0x061 (IOPM Offset 0x0C) has been granted access.
    Executing beep.exe with a ProcessID of 1096
    PortTalk Device Driver has set IOPM for ProcessID 1096.

    This is more secure than allowing all programs and processes access
    to all IO ports.

    If you don't know what addresses a certain program uses, you can
    grant access to all ports.

    C:\porttalk>allowio beep /a
    BeyondLogic AllowIO
    Granting exclusive access to all I/O Ports
    Executing beep with a ProcessID of 524
    PortTalk Device Driver has set IOPM for ProcessID 524.

    This is less secure. For example the program can talk to COM1
    and lock up your mouse.

    Craig Peacock
    13th January 2002
    All help appreciated.thanks.

  5. #5
    Senior Member Cyborg
    Join Date
    Sep 2004


    Hi Aditya,

    Though your parallel port may have 3 possible port addresses:
    0x3BC, 0x378, 0x278

    Im wondering how correct is the output of the C-program which you downloaded ? (which shows you the port-address)

    it would be better if you simply see the base address in Bios settings , or through windows xp: as given here,00.htm

    if its correct, then you may like to read the beyond logic tutorials and porttalk pages again, in detail.

    cheers & goodluck!

  6. #6


    oh i forgot to mention,
    on some machines it is necessary to change the port mode
    TO--> "Standard Mode"
    from ECP or some thing else.
    done In--> Bios settings...
    these are usually P4 class machines...


  7. #7
    Senior Member T-1000
    Join Date
    Jun 2004


    SPP should is EPP...mines on ECP and works like a breeze...
    U get a split second boew of ur parallel port address at start up...
    On windows+Pause break

    Select the Hardware tab...
    Go to device manager.
    Select ur Parallel port
    go to RESOURSES
    and check ur base address.

    Now u know ur base address.If thats right ,then there something else going wrong...keep us posted

  8. #8
    Senior Member T-1000
    Join Date
    Jun 2004


    Hmmmm...didn't read the above posts...Since ur sure ur address is 3BC..

    Is ur port working...?

    Not sure....Get someone's printer home and check if the printer is workin..

    Third...can't do the second..
    I assume ur in an Engg college..Use one of ur lab PC's parallel port.

    Ur program is simple .Shoul've worked..How many parallel ports do u have.Most of the time it's one,but sometimes there are 2.

    Another thing did u try checking the inputs?

  9. #9
    Member Advanced User
    Join Date
    Sep 2004


    Hi ,
    Try this utility at MIG India :

    MIG India

  10. #10


    Hi guys,thnaks a lot for replying.There still seems to be problems .Here's what i did.
    I went to this link
    http://<br /> <a href="http://asia.....htm</a><br />
    (thanks to vivek) which gave me almost everytihng i wanted.I chacked the port addresses in the Bios (i got 0x378) the program i downloaded was erroneous.In the Bios there were 3 modes:ECP,EPPandBI-directiona(default was ecp)l.I used bi-directional.Then I changed the parallel port conf. in the device manager and i thought i was ready to go.but i was still getting 4.52v from all the pins in lpt1.
    Then i checked this link which says something about a new dll for i/o access
    but i think i have to use Vc++ for that.
    http://<br /> <a href="http://www.l....htm</a><br />
    but i will use that as a last resort.Maybe i will try epp and see what happens.
    Pulkits files also seem to be using inout32.dll.Pulkit can u ad like a browse button to like upload a file directly to the port?also,a confirmation mesg. saying the port has been opened or something?
    Also can anyone try porttalk22 on their comp. and tell me if it works or not.It can be found at
    http://<br /> <a href="</a><br />
    Also ice what do u mean by checking the inputs?I am sure my ports are working fine.
    Any suggestions welcome.again,thanks a lot everybody.

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