Date: Wed, 5 May 1999 19:18:10 -0400 From: "Mark Turpin" <mturpin@spel.com> To: "Jean-Michel DRICOT" <jdricot@ulb.ac.be> Cc: <questions@freebsd.org> Subject: Re: Writing directly to PC Parallel Port Message-ID: <006101be974d$8ae9b2c0$8227e2d0@spel.com> References: <37303C6F.2BAD8B47@ulb.ac.be>
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you'll need to open /dev/io then outb should work.
like this....
open("/dev/io",O_RDWR);
outb(0x378, 0xFF);
----- Original Message -----
From: Jean-Michel DRICOT <jdricot@ulb.ac.be>
To: FreeBSD Questions <freebsd-questions@FreeBSD.ORG>
Sent: Wednesday, May 05, 1999 8:41 AM
Subject: Writing directly to PC Parallel Port
> Hello,
> I found this small code (see attachement) on the Web. It is for Linux
> and I tried compiling it.
> I get first error from "ioperm" function that BSD know how to handle.
> I fired it and tried aganin. This time it compiled but didn't run (core
> dumped :-) ).
>
> I wonder thus how to write directly to ports with FreeBSD. I'd like to
> write bits directly to the port. Assembly code like "outb" and so
> doesn't seem to be enough...
>
> Any idea ?
>
> Thanks
>
> jim
>
> ________________________________________________________________________
>
> "Unix IS user friendly. It's just selective about who it's friends are."
>
> Dricot Jean-Michel
> 3eme Annee du grade d'Ingenieur Civil Informaticien
> Universite Libre de Bruxelles - Ecole Polytechnique
>
> URL: http://student.ulb.ac.be/~jdricot
> e-mail: jdricot@ulb.ac.be
>
>
----------------------------------------------------------------------------
----
> >From joev@mikasa.WPI.EDU Sun Jan 1 18:34:40 EST 1995
> Article: 144 of comp.os.linux.development.system
> Path:
bigblue.oit.unc.edu!concert!gatech!bloom-beacon.mit.edu!news2.near.net!news.
mathworks.com!bigboote.WPI.EDU!mikasa.WPI.EDU!joev
> From: joev@mikasa.WPI.EDU (Joseph W. Vigneau)
> Newsgroups: comp.os.linux.development.system
> Subject: My LED performance meter thing...
> Date: 1 Jan 1995 23:18:28 GMT
> Organization: Worcester Polytechnic Institute
> Lines: 147
> Message-ID: <3e7d84$or5@bigboote.WPI.EDU>
> NNTP-Posting-Host: mikasa.wpi.edu
>
> Last week, someone wrote here asking about robotic contol via Linux... I
> responded explaining how I used the parallel port to control a sort-of
> "performance meter". I've recieved a lot of requests on how I did this.
> Here's the story:
>
> Last year, at school (WPI), Silicon Graphics brought this huge 18-wheel
> truck that is basically a demonstrationmobile. Inside it had Indys,
> Crimsons, and some of their big machines like a couple of Onyxes and an
> *monsterous* Power Challenge.. I'm relatively young (17 at the time), and
> I'd never seen a computer this big before: It looked like an oversized
> refrigerator, with cooling ducts running in and out of it! On the front
of
> this beast, was a little LCD backlit readout about the size of my HP-48G's
> display. It was labeled "CPU Activity", and had a little bar chart
showing
> how hard each processor was working. I thought it would be cool to have
one
> of these mounted on my Linux box :)
>
> I finally got a computer of my own this past November, and finally got to
run
> Linux on my own, instead of administering it for a number of people on my
> floor. I had a Shack attack, and went to Radio Shack, and picked up the
> following items: a breadboard, a 10-bar LED, breadboard wires, and a
> package of assorted resistors. [Side note: While at the Shack with a few
of
> my suitemates, we were way in back in the component section (the only good
> part of the store any more), and were approached by a lady who thought we
> were employees there :). Back to the project.]
>
> It was wired up like this, via the parallel port:
>
> pin 20 (ground)
> |
> 150ohm LED |
> pin 2 (D0) ----/\/\/------|>|-----+
> |
> pin 3 (D1) ----/\/\/------|>|-----+
> |
> pin 4 (D2) ----/\/\/------|>|-----+
>
> [...]
> |
> pin 9 (D7) ----/\/\/------|>|-----+
>
> Note: 2 of the LEDs weren't connected.
>
> Now, the software part:
>
> Two files were used: the first is a routine written by a roomate
> (damianf@wpi.edu) used to blast raw bytes at a port, and read them. Please
> contact him for more info, or if you want to use it in a progrm of your
own.
>
> static inline int port_in( int port )
> {
> unsigned char value;
> __asm__ volatile ("inb %1,%0"
> : "=a" (value)
> : "d" ((unsigned short)port));
> return value;
> }
>
> static inline void port_out( unsigned short int port, unsigned char val )
> {
> __asm__ volatile (
> "outb %0,%1\n"
> :
> : "a" (val), "d" (port)
> );
> }
>
> I originally wanted to use the load average to determine how many of the
> LEDs lit up, but realized that it was only updated every minute.. I wanted
a
> display similar to xload or xosview, but I really coun't figure out how
they
> were determined.. What I ended up doing was reading the output of 'ps
aux',
> and summing up the %CPU column. I then converted that into a number
> representing how many LEDs should light, and blast it at the printer port.
>
> NOTE: I wrote and built this thing in a bout 90 minutes, so it's quick and
> dirty, and not at all as elegant as I hoped it to be.
>
> Here's the program:
>
> /* meter.c by Joseph W. Vigneau (joev@wpi.edu) (c)1994.
> This program is covered under the GNU copyleft agreement.
> */
>
> #include <stdio.h>
> #include <unistd.h>
> #include <errno.h>
> #include <time.h>
> #include "port.h"
>
> float loadavg(void)
> {
> FILE *f;
> char line[80];
> float cpu = 0.0, totalcpu = 0.0;
>
> if((f = popen("/bin/ps -aux","r"))==NULL) {
> fprintf(stderr,"Couldn't fork /bin/ps.\n");
> exit(1);
> }
>
> fgets(line, 80, f);
> while(!feof(f)) {
> sscanf(line,"%*s %*d %f",&cpu);
> totalcpu += cpu;
> fgets(line, 80, f);
> }
> /* printf("TOTAL: %f\n",totalcpu); */
> pclose(f);
> return totalcpu/100.0;
> }
>
>
> main()
> {
> unsigned char lights;
> float ave;
> char dir = 0;
> char foo[10];
> register unsigned char numlights, i;
>
> if(ioperm(0x378,1,1)) {
> fprintf(stderr,"ioperm error.\n");
> exit(1);
> }
>
> while(1) {
> ave = loadavg();
> numlights = (int)(ave*8.0);
> /* printf("ave = %f, numlights = %d\n",ave, numlights); */
>
> lights = 0;
> for(i=0;i<numlights;i++)
> lights |= (1<<i);
>
> port_out(0x378, lights);
> usleep(750000L);
> }
> }
>
> This program has to be suid root, due to the ioperm call.
>
> Good luck, and have fun! Your mileage may vary.. If this makes your
computer
> explode or something, I'm not responsible, etc.. If you improve upon
this,
> post it here, so everyone else can see!
>
> --
> joev@wpi.edu WPI Computer Science '97
Linux!
> <a href="http://www.wpi.edu/~joev">; Click Here! </a>
>
>
>
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