[fpc-pascal] Parallel Port Access with Free Pascal - windows
James Richters
james at productionautomation.net
Sat Jul 23 12:53:23 CEST 2016
Thank you for getting me on the right track with this Marc, I have it
working now!
Here is a link I found that explains it:
http://www.freepascal.org/docs-html/ref/refsu72.html
I would have never thought of that!
I posted the fixed program on github here if anyone is interested:
https://github.com/Zaaphod/FPC-Parallel-Port
I tested it the Inp32 and Out32 functions and they are now working!
Thank you everyone very much for the help with this!
-----Original Message-----
From: fpc-pascal-bounces at lists.freepascal.org
[mailto:fpc-pascal-bounces at lists.freepascal.org] On Behalf Of Marc Santhoff
Sent: Saturday, July 23, 2016 1:09 AM
To: fpc-pascal at lists.freepascal.org
Subject: Re: [fpc-pascal] Parallel Port Access with Free Pascal - windows
On Sa, 2016-07-23 at 05:55 +0200, Marc Santhoff wrote:
> On Fr, 2016-07-22 at 18:20 -0400, James Richters wrote:
> > I'm trying to avoid custom hardware if possible. I have always used
> > parallel ports and never had a problem with them until now. I like the
> > idea of a parallel port because they are still built onto motherboards,
and
> > there are also a TON of USB to parallel port adapters out there. I'm
> > trying to keep this simple.
> >
> > I put a repository of my test program here:
> > https://github.com/Zaaphod/FPC-Parallel-Port. Perhaps someone can see
what
> > I'm doing wrong. I'm reading 255s no matter what I do. I included
my
> > old turbo pascal test program. I would normally specify the port in
> > hex with a $ like this $378. I could write to the port then read
> > back what I just wrote.. which is what I am trying to do now.. I
> > don't have anything hooked up to the port yet, I should be able to write
to it and read it back.
> >
> > I seem to be accessing the DLL correctly, because I tried it on a
> > windows 7 computer and IsInpOutDriverOpen was false, because I
> > forgot to install the driver, once I installed the driver
> > IsInpOutDriverOpen is now true, so that tells me I'm accessing the DLL
and the DLL is confirming the driver is open.
>
> >From what I know, although it may be a bit outdated, on windows
> >external
> functions have to be declared 'cdecl'. Which isn't so in the library
> port to pascal.
>
> One example:
>
> implementation
> Function IsInpOutDriverOpen; external 'inpout32.DLL';
>
> would then be:
>
> implementation
> Function IsInpOutDriverOpen; cdecl; external 'inpout32.DLL';
No, sorry. It has to be the other way round:
Function IsInpOutDriverOpen; {$ifndef Win32}cdecl{$else}stdcall{$endif};
external 'inpout32.DLL';
I didn't recognize that it is $ifndef, not $ifdef.
Marc
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