PC ports, Encoder resolution and EDM PSU info

Hi All

I'm new to this group (about 10 days listening). Fascinating!

Three queries which I'm sure someone will know about...

1) Has anyone considered using the EIDE interfaces on the PC boards to interface out to the real
world? Seems it's a very simple interface to use, with 8 off 8/16 bit read writable addresses?
There's usually at least one spare on a low end machine, and it's easy to get 2 extra ports on an
add-in card.

2) Having 'sparked' an interest in EDM (and reading The EDM Handbook for starters), does anyone have
a source of info on the PSU designs used (seems it's mainly proprietary black magic), and how fast
does the wire move in wire EDM (the handbook above never mentions this).

3) re encoders on lathes to enable CNC threading, I see the Microkinetics units are 200 or 400 per
rev, with pseudo-800 using all edges. Say with 1 thou periphery movement then 800 only allows
0.8/pi, or only a 1/4 inch diameter item. Seems very small to me, where have I gone wrong? I've
seen encoders with 5000 steps, which seems more likely to be needed.

Cheers
Dennis Fielder, Cambridge, England