Parallel Port I/O Access Under Win2K?

stumped-by-MS asks: "I'm having a tough time accessing my parallel port under Win 2K. I'm working off of a Dell Precision P4 workstation, and using Microsoft ASseMbler to run simple programs involving IN and OUT commands. Initially I read about 2K's strict I/O control, and found the PortTalk driver to get around it. This driver, when coupled with the supplied allowio.exe, is supposed to give any program User level 0 to any specified port. Using the program (syntax: allowio test.exe 0x378 ) allows access to the base address just fine, however with base+1 (0x379), the input port, is still unresponsive. Using allowio to specifically give access to that port also fails, as well as giving my program access to all ports, which I would rather not do in the first place. " Is there some hidden set of permissions a program must have before they are allowed access to certain I/O ports under Windows 2000?

"Am I missing some concept here? As I understand it, allowing access to base=0378H should give access beyond 0x380! If anyone knows what I am doing wrong, or the location of some software that does things right, it would help me a lot."

DLPortIO

[discoinferno]

Do a search for DLPortIO. (http://www.driverlinx.com)

It has all the answers to your question, and you would have run across it had you really done a search.

Hardware access is restricted.

[eric2hill]

On a Windows 2K/XP box, all hardware-level access is prohibited for user-space programs. Drivers are the only thing that are allowed to talk to hardware.

Go pick up a generic driver that you communicate with to do what you want. See the following...

http://www.torry.net/portaccess.htm

There are many components available for Delphi (with source) to talk to hardware. Port to [insert language here] as necessary. Just remember to use standard calling conventions when calling the DLL.

HeRvoPort

[roryi]

HeRvoPort ( http://www.ks.net/hervoport/ ) does exactly what you need, and is available for Win NT3.1-4.0 on MIPS, Alpha an x86, and for Win2000 on both IA32 and IA64.

An earlier version provides the same control for OS/2

It was developed origingally by Dave Brucken, who came up with the originial FOSSIL (Fido/Opus/SeaDog Standard Interface Layer) serial spec for FidoNet, and it's since been expanded to manage all port access for Windows.

They used to sell a parallel break-out box, and a strange sort of music synth to go with it, but i think that's fallen by the wayside. cool stuff, anyhow.