Re: 5-axis machine controller

["D.F.S." <dfs-at-xmission.com>]

> 
> 
> > I'd hope for something along the lines of --  Move_Axis_Z(Direction, Count)
> 
> No, it is a LOT more complicated than that.  
Good, because I was starting to feel pretty stupid for not being able to 
find it.

> There are 12 layers (well, maybe
> really only 5) of software between the G-code and the step pulses.  EMC
> was originally designed for servos,  so the easiest hack was to simulate
> a servo system, and then generate step pulses from the middle of the
> simulation.  But, you really don't need to know ANY of that to make
> it work.  You don't need to look at the code, it outputs either step and
> direction
> or stepper phase signals from the parallel port.  There is a table of the bit
> assignments somewhere on the Linuxcnc web site.

The only pinouts I have been able to find are for the Step & Direction Type.

I need the other one.

> > I'd like to toggle the bits on the port and drive the stepper coils directly
> > thru FETs. I figure a 3-to-8 ttl Decoder and 3 latches along with a dozen
> > Transistors should do it. I have all that stuff close at hand.
> 
> Well, you really don't need that, as EMC will output the stepper phases
> directly, as an option.

Where do I find the info how to to do that?

I'd like to look at that particular piece of code that sets the bits, and
still can't find it.

and... since I'm running 3 axis and 3 steppers with 4 phases Each I'll
need 12 bits. 
How does it deal with that, without a scheme like I mentioned
without latches, and 8255 or something?


> 
> > What particular distribution and version number of Linux will work
> > with what version number of RT Linux and what version of EMC will
> > work with that?
> 
> I'm using Red Hat 5.2 Linux, with the 0.9J RTLinux patch, and the
> 20-DEC-1999 version of EMC.  
The problem I have is finding any of this stuff currently.
I have the OLD linux releases because I'm a pack rat  and got it new 
years ago, but the 2 web sites only have current releases of 
EMC and RTLinux as far as I can see.

> I think the 2.2.13 kernel with the appropriate RT patch and the latest version
> of EMC is also supposed to be rock solid, but I haven't tried to upgrade
> yet.

Even the Latest stuff is getting a bit hard to find.
The RTLinux stuff appears to have moved on to version 3 although I got what I 
think is the correct source package, the Binary Packages appear to be new or
nothing.

I happen to have a version of Mandrake 7.0, but I bought that 6-8 months ago as
as close-out due to being replaced by 7.1.

Mandrake 7.1 Sucked IMHO, I had much better luck on my laptop by going back to
a new install of 7.0.

Now, you guys are doing a great job, and as long as the software does what it 
should I see no reason to upgrade, but the three times I tried to go get all this
stuff over the last year and a half, I never was able to get the "Complete" set
of everything.  
Is any of this stuff restricted in any way that would prevent
setting up a small archive of a complete set to address this?

As long as it works, Who cares if it is 4 year old verisons of Linux, RTLinux
and EMC as long as someone can still get a complete set.
It's just that In this day and age, this stuff gets superceded and simply 
disappears. The only reason I have old versions of linux is that they are CDs.
Stuff on the net simply disappears.

Please excuse the rant, from looking at the code you guys have clearly put a lot
of time and effort into this, but I still can't seem to get enough stuff together
to get a complete build.

Thanks for the help.

Marc