Re: [CAD_CAM_EDM_DRO] DRO

> I have a small DRO question. I want to build a DRO, but my computer
> does not have a ISA slot, and I don't want to downgrade my workshop
> computer. Is there such a beast as a LPT port DRO card or a PCI DRO
> card???

Yes, I can think of serveral obvious choices, and I am sure there are
others as well:

US digital (www.usdigital.com) sells computer interface modules for
quadrature encoders which connect to the computer in various ways.

I believe there is code floating around somewhere to directly read the
quadrature signlas in via the parallel port. The problem with this is
that if the computer gets distracted or the encoder is pulsing more
rapidly than expected, it may loose count. But it may well be fine
for use at a limited resolution on a manual machine with not much else
running on the computer.

Or one could buid something using the same chip (LS7266) from US
Digital used on the ISA card kit popular here, only talk to it via the
parallel port. You would have to do some software work on your own,
and would need to verify that you computer has a bidirectional
parallel port.

Chris Stratton

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Christopher C. Stratton
Engineer, Instrument Maker, and Horn Player
ccs@... 617 628 1062
http://web.mit.edu/~stratton/www/brassbuild.html