Re: [CAD_CAM_EDM_DRO] Re: The mechanical part of my router is done!

OK, guys...I need a little bit of help. Who's good with electronics?

I have bought 3 stepper controller boards -- they are based on the
L297/298 chipset, and run my motors very nicely. The down side is that
they have an on-board pulse generator -- no hookup for a parallel port.
Which means...modifications!

Here's the schematic for the board -- it's a surplus board from TI.
http://makeashorterlink.com/?V59F32F45

As I see it, I need to bypass the 555...cut the lead between pin3 on
the 555 and pin 17 on the 297, which is step input. And I need to hook
into pin 18 on the 297, which is direction. Of course it didn't work
like this, which is why I'm asking for help.

Assume nothing -- I've played with serial ports, but I'm not sure about
parallel interfaces -- does anything need to be tied to ground, a state
or enable pin tied such that it is active, etc?

Now, all of this, I can do (though maybe with some help from you
guys)...is there any real danger of blowing something out? I live in a
TINY town, and having to build a breakout board, or something similar,
would add in a week's delay, just because of the unavailability of parts
in this area. To be honest with you all, I just want to see my motors
spin under computer control! Down and dirty hacks are fine, at this
stage of the game.

HELP?!

-- Chuck Knight