RE: Parallel port inactive

[Tim Goldstein <tgoldstein-at-mlh-services.com>]

Seems to me that there are quite a number of issues with EMC working on a
486. I thought it was discussed that to get it working would require many
changes for the real time extensions to work properly with the memory
arrangement of a 486?

Tim
[Denver, CO]


> On Thu, 29 Mar 2001, Wallace wrote:
> 
> > Hello,  I have just set up EMC on a 486Dx33 with Redhat 5.2 and the
> > associated RTlinux patch.  I have also been able to get it 
> to run using the
> > steppermod.o and minimillio.  The problem that I am having 
> is that although
> > I can get it out of estop and jog the axis I cannot get any 
> activity on the
> > parallel port.  I have an oscilloscope set up to read the 
> port pins and they
> > just stay at +5V.  The port is set up at 0x378.  Any 
> suggestions would be
> > helpful.
> > 
> >  I also wouldn't recommend this slow of a processor for 
> more than getting
> > set up experience, it can just run xemc but is not even 
> usable with tkemc
> > (well unless you can wait 30 sec for the mouse to move)
> 
> Wallace
> 
> Welcome and congratulations on getting the install successfully.  
> 
> You might try running a little script that is in the emc/tcl/scripts
> directory.  It is called IO_Exercise.  It must be run from the emc
> directory but can stand alone.  For this test, don't run the 
> EMC at the
> same time.  The command would be
> 
> cd usr/local/***/emc (replace *** with whatever for your machine)
> tcl/scripts/IO_Exercise.tcl
> 
> and you should see a wish window with several buttons and labels.
> 
> Set the address to show to 378 and the address to change to the same
> and then click some set pin buttons on the right and you will see
> the number above those buttons change to a new value.  Press 
> number set
> and you should see the lamps change on the left side of the window. 
> 
> If no change, the parport is dead or not at that address.  If 
> the lights
> change but you see no change on the scope, then you need pull 
> up or pull
> down resistors or an external 5 volt supply.  For slow tests like
> IO_Exercise, the scope is not the best instrument to use.  A 
> multimeter may
> be easier to read and if all else fails, you can use the ohms 
> scale and
> watch for an npn junction attempting to short a pin to ground.
> 
> IO_Exercise can also be used to watch for signals into the parport by
> setting the value to 379.  You can also use IO_show in the 
> same directory.
> 
> Hope this helps.  
> 
> Ray
>