Re: [CAD_CAM_EDM_DRO] Laptops

Hi Terry, James, Bill,

You don't want to add a second opto-isolator (Geckos already have 'em).
A simple 74LS series buffer I.C. will do the trick.

Also, most parallel ports can SINK more current then they can source.
The output gate in the parallel port "pulls down" the interface line.
You use the +5V and the parallel port lines from the PC, the ground line
is not needed.

HTH

Alan KM6VV


James Owens wrote:

>
> Hi,
>
> Surely this can be cured by using an opto-isolation board? There are however
> some problems with how laptops use the system clock. Art can tell you more
> of this on the Master 5 list.
>
> Regards,
>
> Terry
>
> > I have seen quite a few problem using laptops with Gecko's because a
> > lot of them will only put out 3.2V on the parallel port. Marriss
> > repeatedly insists that you have at least 4.2V on the step and direction
> > lines and 5VDC is better.
> > Use a destop PC and save your self a lot of problems.
> > Dan
>