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[DavidR]

I wish to use a free dll that allows direct port access under 2000/NT/XP. I've experimented with it a bit but really don't have a firm grasp of the proper calling procedures. The developer has posted details for Delphi (as well as C & VB) so hopefully someone here can get me pointed in the right direction with some examples of the correct syntax.
The software is available at http://www.geekhideout.com/iodll.shtml
The instructions for Delphi are as follows:

Delphi Prototypes
procedure PortOut(Port : Word; Data : Byte);
procedure PortWordOut(Port : Word; Data : Word);
procedure PortDWordOut(Port : Word; Data : DWord);
function PortIn(Port : Word) : Byte;
function PortWordIn(Port : Word) : Word;
function PortDWordIn(Port : Word) : DWord;
procedure SetPortBit(Port : Word; Bit : Byte);
procedure ClrPortBit(Port : Word; Bit : Byte);
procedure NotPortBit(Port : Word; Bit : Byte);
function GetPortBit(Port : Word; Bit : Byte) : WordBool;
function RightPortShift(Port : Word; Val : WordBool) : WordBool;
function LeftPortShift(Port : Word; Val : WordBool) : WordBool;
function IsDriverInstalled : Boolean;
Important! To use these functions in your Delphi program, the correct calling convention of stdcall is required. For example:
procedure PortOut(Port : Word; Data : Byte); stdcall; external 'io.dll';

Here's a couple of lines that returns the expected result from the simplest function but I'm kind of lost after this..

[Hooligan]

David,

Just a guess on my part...
I suspect that this dll is designed to address io ports directly through the port's address, i.e. instead of using "COM1", you would have to use "3f8", assuming COM1 is assigned that address. Your usage would now look like this: info @LIB(io.dll,PortIn,STR:,INT:@binary(word,3f8))
To break down what was done:
@lib( - perform a library call
io.dll, - the library being called
PortIn, - the function within that library being used
STR:, - the TYPE being returned (in this case, a character in the form of a string)
INT:@binary(word,3f8) - the value being passed to the function (in this case, the port address) and its TYPE (word integer)

I hope this helps (and that I got it right...)
Hooligan

[DavidR]

Thanks for the replies, I'm making some progress with this but another question comes up.
I'd like to (programatically) determine the base address of the Parallel ports installed on a particular computer. I can get this information by running debug in a command window and examining 0000:0408 where the base address of LPT1 is stored, Or I can look in the control panel under system/hardware but I'd like my program to be able to get this information on its own. I thought it might be available in the registry but was unable to locate it. Perhaps there's an API call that can return this number?
Any ideas ?
Thanks........
..............David