Hi.

>
> At 08:52 AM 3/3/98 +0000, you wrote:
> >        Hi.
> >        In short, yes, if Murphy is hanging around. But let us see the
> reasons.
> >        If printer and computer have not the same ground, they may be at
> >different voltages, or simply one of them has some electrostatic charge.
> >When you introduce the connector, nobody assures you that gnd will go in
> >first (unless a very well built cable, taking these things into
> consideration).
> >Therefore, during some tenths of a second, there may be a great current
> >flowing through signal pins while the two devices exchange electrons, which
> >will destroy that or those signals.
> >        If your system is well grounded, not a great risk; I do it all
> >the time with those I use.
> >
> How do I know if my system is well grounded?
>
> Thanks,
>
> Changhsu Liu
>

        A home solution is with an ohm-meter. First, check the AC and DC voltage
between signal gnd's on the connectors, and if near to 0, check the resistance
between them: should be fractions of ohm.
        But don't risk and don't connect while on.
************************************
Javier Vizcaino. Ability Electronics. [log in to unmask]

Starting point:        (-1)^(-1) = -1
Applying logarithms: (-1)*ln(-1) = ln(-1)
Since ln(-1) <> 0, dividing:  -1 = 1
     (ln(-1) is complex, but exists)