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Date:      Tue, 29 Oct 2002 17:08:45 +0100
From:      Bernd Walter <ticso@cicely8.cicely.de>
To:        Joe Sunday <sunday@csh.rit.edu>
Cc:        David Nicholas Kayal <davek@saturn5.com>, freebsd-hackers@FreeBSD.ORG
Subject:   Re: i am looking for a 5 volt signal
Message-ID:  <20021029160844.GA16922@cicely8.cicely.de>
In-Reply-To: <20021028135635.GA28293@csh.rit.edu>
References:  <Pine.BSF.4.44.0210270911490.329-100000@blackbox.yayproductions.com> <20021028135635.GA28293@csh.rit.edu>

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On Mon, Oct 28, 2002 at 08:56:35AM -0500, Joe Sunday wrote:
> On Sun, Oct 27, 2002 at 09:12:33AM -0800, David Nicholas Kayal wrote:
> 
> > I'm looking for a 5 volt signal.
> > 
> > I have wires plugged into pins 2 and 25 of the parallel port.
> > 
> > I have written a small program:
> > 
> > #include <stdio.h>
> > #include <dev/ppbus/ppi.h>
> > #include <dev/ppbus/ppbconf.h>
> > 
> > int main()
> > {
> >   int fd;
> >   while(1)
> >     {
> >       ioctl(fd, PPISDATA, 255);
> >     }
> > }
> 
> PPISDATA actually takes an int* argument. (The man page may be a tad
> confusing here.)

No it takes an u_int8_t* exactly as written in the manpage.
Using an int doesn't work in all cases.
I have no idea what part of the manpage is confusing.

> Try
> int main() {
>     int fd;
>     int d = 255;
u_int8_t d = 255;

>     fd = open( "/dev/ppi0", O_RDWR );
> 
>     ioctl( fd, PPISDATA, &d );
> 
>     return 0;
> }

-- 
B.Walter              COSMO-Project         http://www.cosmo-project.de
ticso@cicely.de         Usergroup           info@cosmo-project.de


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