Newbie parallel port question

[hedg12]

First off I have to say great job on Vixen! I've used LOR in the past & have to say Vixen is much more capable, and FREE! Thanks, KC.

I'm planning on using Vixen to control some Halloween props this year, and I'm running into some issues. I've based my planning on the assumption that the basic parallel plugin simply sets the data pins on the parallel port (2-9) "high" when the corresponding channel is on, and "low" when it's off. However, I've done some simple testing with a volt meter and a simple sequence, and have not been able to get any response from the port. Pins 2-5 are "high" all the time, and 6-9 are "low." I'm running Win2K on a 1Ghz Via mini-ITX board with 512 megs of ram, and had no problem with the installation or configuration. Anyone have any thoughts on this, or am I incorrect in my assumptions about the function of the plugin? (You know what they say about assuming making an A** out of U and ME!)
Thanks,
Jason

[teberle]

There have always been issues with how the parallel port is setup in the bios. My is epp and that seems to work with all of the parallel boards.

I also believe your assumption is correct.

[hedg12]

Thanks, I'll check the settings tonite.

[P. Short]

Which mini-itx board? Apart from the issues that you mention here, I've used a scope to look at the parallel port signals on the rather old 1G mb (EPIA-V) mb that I have, the waveforms are not very good. The voltage levels on the data signals are rather low, and the rise times on the control signals are pretty big.

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Phil

[ErnieHorning]

I always wondered if the cure would have been to use the nAck and/or the Busy lines like a printer would. Or even if we would have used the ECP mode with its automatic handshaking capabilities like Tony had proposed. This would have slowed the port down to operate within its own rise/fall times.

If some one hadn’t come up with a much better controller using PIC’s, we probably would have. :)

[P. Short]

Ernie,

I think that you've hit the nail on the head. The only other issue is making sure to use the right drivers and receivers (TTL-level).

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Phil

[hedg12]

It is in fact an old EPIA-V. I'll run some tests on the board itself tonite. I'm not planning to use it w/ a relay card (ala Kit-74), I'm interfacing it with the device directly. I just need + 4-5 V.

[P. Short]

Some oscilloscope waveforms are here, towards the bottom of the page. However, it turns out that I was looking at an even older 800 Mhz mb, not the EPIA-V, so ymmv.

http://luminous-dots.blogspot.com

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Phil

[hedg12]

I changed the port settings to EPP in the BIOS & that solved the problem. Thanks for the help. My skull will be talking in no time.