Re: [CAD_CAM_EDM_DRO] Mach3 & laptops

Danny,

The problem is not with accessing the parallel port, but with the
internal timing of the Mach3 program.

Mach3 uses a special kernel mode software driver which is necessary to
provide high precision timing required to get all the various step
pulses out the door at the precise instant needed for a proper cut.
Laptops have all sorts of integral proprietary hardware with special
drivers that confuse the dickens out of Mach3.

When you get down to it, it's pretty amazing that Mach3 works as well as
it does, considering that even on a desktop, Windows is a highly
non-deterministic operating system. It takes a lot of high power
programming on Mach3's behalf to make sure Windows does not decide that
NOW is the time it has to do a defrag, just as you are half way through
the 4167th line of your G-code program. Laptops just add a whole
'nother layer of complexity to the issue.

Since Mach3 will run just fine on an old Pentium 3 that you can snag for
free at curbside on trash day, it's just not worth the developers'
effort that would be required to make it compatible with laptops,
particularly when nearly every laptop is a collection of custom parts.
(Have you ever tried to buy a replacement keyboard or LCD for a laptop?
-- essentially every model is unique, and the corresponding internal
software drivers are similarly unique).

I'm pretty sure that Mach3 directly writes to the parallel port I/O
pins, and will not work on a USB to Parallel adapter, at least not in
the versions that I was familiar with.

HTH,

Dave

Danny Miller wrote:

> I was looking to set up Mach3 & a Taig with a laptop, and saw on
> Artsoft's website that "Laptops are not supported because the power
> saving features of the chipsets disrupt the pulse stream".
>
> What's the real story here? ALL laptops?? I'm kinda having a hard time
> believing this. Parallel ports are usually designed to... well, /work/
> at transferring data as designed. It's kind hard to even see this
> statement as credible, I mean the explanation borders on the absurd,
> power management and the parallel port datastream are two different
> things. Will this actually not work?
>
> And what's a "non-integrated video card", one that's not on the mb like
> a laptop? Why would that matter?
>
> My laptop does have a parallel port built into it. I could also get a
> USB-to-parallel port cable. That would add the complexity of the
> internal bridge and all but it would use a different data path than the
> internal serial port.
>
> Thanks,
> Danny