RE: [CAD_CAM_EDM_DRO] Re: Interface. Gauging interest.

Dave,

I think I know what you're talking about. Basically 8-bit data getting
clocked out with a strobe, and waiting for a "ready" or a "not busy". If we
simplified our interfaces to just the step/dir bits, and wrote enough bytes
to get the pulses started/stopped, one MIGHT be able to do some minimal
stepper motion through such a "virtual" driver. I don't believe it would
ever be enough to really run CNC. We need a windoz driver that allows us to
"own" the real parallel port, and be called by our program. I wrote DOS
drivers, windoz has something similar. But it's all for not, as windoz can
take the processor whenever it wants, and there goes your timing!

Better to send "commands" at some level, and let a little uP on the other
side of the USB interface do the timing, I think!

I'm driving steppers from PICs, now just do the same development/learning
curve in getting multiple steppers and coordinated moves in a PIC (or other
uP) along with the USB framework!

Alan KM6VV

> Windows used to have an option for printers that would let you 'capture'
> a printer to an lpt port so that DOS applications could print. I don't
> see it in windows XP or NT any more, but if you have an older version of
> windows somewhere you might try turning on that option. Evidently it
> would rig up the IO space in the DOS box so that writes to the printer
> port would be redirected to the captured windows print driver.
>
> There's a chance that you could get a DOS program like TurboCNC to
> output pulses to a USB parallel port with something like that. Of
> course the timing would be shot all to hell and the pulse stream nearly
> useless, but if it works you could probably at least send a motor into
> fits with it :)
>
> Dave K
>