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Author Topic: erratic pulse train fix?  (Read 7143 times)

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Offline Hood

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Re: erratic pulse train fix?
« Reply #10 on: June 10, 2013, 01:25:27 PM »
That is basically what it boils down to, some computers will be fine, some will not but of the "nots" some can be made to work with doing the optimisation steps.

More modern computers with onboard graphics stand a better chance of being good than older with onboard graphics.
I did the driver test on an Atom mobo a while back, I was using an external controller so didnt need to but I was curious. It had the flattest smoothest line I have ever seen in the driver test, and that was testing at all frequencies right up to 100KHz.

So its just a case of try and see I am afraid or if you can get specific models/makes to use from someone like angel tech or ones to avoid such as the models Rich tried then thats a good way. .


Offline RICH

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Re: erratic pulse train fix?
« Reply #11 on: June 10, 2013, 07:15:01 PM »
Sorry, but I didn't keep track of the Dell's model numbers as we tried them but the problem was typical in that each had on-board graphics and had ringing on the signal. Additionaly the driver test would show pulse rate was not near
the test pulse rate ( say 20k instead of 25k).  The one I am currently on at this moment, GX520, is fine for everything but just sucks for use with Mach.

Have an old laptop ( NEC with PP and runs Mach with no problem ........but it is so slowwwwwwwwww......

Had a computer put together for me and works fine. So do the driver test and look at the signal if you can and decide form there is the only true advice I can give.

Re: erratic pulse train fix?
« Reply #12 on: June 11, 2013, 12:18:17 AM »
I have the system working.

I switched XP from ACPI to "Standard PC" and the pulse stability was good when I used the test utility. I set the BIOS to disable ACPI too. I also found that the BIOS offered EPP and ECP modes for the parallel port, plus a mode called EPP + ECP. The latter does the trick to get bidirectionality, though I think EPP alone is supposed to do this.

MACH3 still shows occasional deviations from a steady pulse stream and the "charge pump" fault detector on the G540 trips. I have switched that facility off.

The machine now runs with a smooth jog and I'm currently exercising it with 100,000 random G00 vectors in a 48" x 48" x 6" volume.

Incidentally, the board has a crappy Via/S3 graphics processor but I doubt that it is causing any of my problems.
Re: erratic pulse train fix?
« Reply #13 on: June 11, 2013, 12:21:44 PM »
i'll try that on one of the novatechs here, well spotted.